The phenomenon of natural convective flow being there with magnetic field in a trapezoidal cavity with cold triangular obstacle for different leaning angles ф (ф=0°, 30°, 45°) has been studied in this work numerically. The horizontal wall of the cavity is considered as non-uniformly heated while the upper wall of the cavity is thermal insulated and other side walls are at a cold temperature. Finite element technique of Galerkin weighted residual method (GWRM) is used to solve the principal partial differential equations. The numerical calculations are worked out for magnetic field parameter, such as, Hartmann number, Ha (0≤Ha≤200), which is used to find the effects on flow and temperature field and the study is also executed for other buoyancy parameters Rayleigh number, Ra (103≤Ra≤106) and Prandtl number, Pr = 0.7 and also for diverse orientations or rotations (0°≤rot≤90°) of cold triangular obstacle of the cavity. The obtained results are demonstrated in terms of streamlines, isotherms, heat transfer rates as well as local and average Nusselt numbers affected by the rotations of cold triangular obstacle and also aforesaid parameters.The phenomenon of natural convective flow being there with magnetic field in a trapezoidal cavity with cold triangular obstacle for different leaning angles ф (ф=0°, 30°, 45°) has been studied in this work numerically. The horizontal wall of the cavity is considered as non-uniformly heated while the upper wall of the cavity is thermal insulated and other side walls are at a cold temperature. Finite element technique of Galerkin weighted residual method (GWRM) is used to solve the principal partial differential equations. The numerical calculations are worked out for magnetic field parameter, such as, Hartmann number, Ha (0≤Ha≤200), which is used to find the effects on flow and temperature field and the study is also executed for other buoyancy parameters Rayleigh number, Ra (103≤Ra≤106) and Prandtl number, Pr = 0.7 and also for diverse orientations or rotations (0°≤rot≤90°) of cold triangular obstacle of the cavity. The obtained results are demonstrated in terms of streamlines, isotherms, heat transfer ra...
{"title":"A comprehensive analysis of natural convection in a trapezoidal cavity with magnetic field and cooled triangular obstacle of different orientations","authors":"M. S. Hossain, M. A. Alim, L. S. Andallah","doi":"10.1063/1.5115848","DOIUrl":"https://doi.org/10.1063/1.5115848","url":null,"abstract":"The phenomenon of natural convective flow being there with magnetic field in a trapezoidal cavity with cold triangular obstacle for different leaning angles ф (ф=0°, 30°, 45°) has been studied in this work numerically. The horizontal wall of the cavity is considered as non-uniformly heated while the upper wall of the cavity is thermal insulated and other side walls are at a cold temperature. Finite element technique of Galerkin weighted residual method (GWRM) is used to solve the principal partial differential equations. The numerical calculations are worked out for magnetic field parameter, such as, Hartmann number, Ha (0≤Ha≤200), which is used to find the effects on flow and temperature field and the study is also executed for other buoyancy parameters Rayleigh number, Ra (103≤Ra≤106) and Prandtl number, Pr = 0.7 and also for diverse orientations or rotations (0°≤rot≤90°) of cold triangular obstacle of the cavity. The obtained results are demonstrated in terms of streamlines, isotherms, heat transfer rates as well as local and average Nusselt numbers affected by the rotations of cold triangular obstacle and also aforesaid parameters.The phenomenon of natural convective flow being there with magnetic field in a trapezoidal cavity with cold triangular obstacle for different leaning angles ф (ф=0°, 30°, 45°) has been studied in this work numerically. The horizontal wall of the cavity is considered as non-uniformly heated while the upper wall of the cavity is thermal insulated and other side walls are at a cold temperature. Finite element technique of Galerkin weighted residual method (GWRM) is used to solve the principal partial differential equations. The numerical calculations are worked out for magnetic field parameter, such as, Hartmann number, Ha (0≤Ha≤200), which is used to find the effects on flow and temperature field and the study is also executed for other buoyancy parameters Rayleigh number, Ra (103≤Ra≤106) and Prandtl number, Pr = 0.7 and also for diverse orientations or rotations (0°≤rot≤90°) of cold triangular obstacle of the cavity. The obtained results are demonstrated in terms of streamlines, isotherms, heat transfer ra...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128283895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noise has always been a major disturbance for every living creature. Noise pollution is, thus, a threat to environmental pollution too. The noise created by a helicopter draws a great contribution to the noise pollution. Reducing the noise that creates from helicopter rotor blades, tail rotors, engine etc. is a one step closer to this crisis. Helicopter noise reduction is a topic of research into designing helicopters which can be operated more quietly. The major source of the noise come from the rotor blade vortex interaction. By attaching spoiler in the helicopter main rotor blades and tail rotors reduce the noise and silence the operation. The spoiler is made of supple, resilient, and durable non-ferrous material, such as rubber, a rubber like material, plastic, rubber-impregnated with thin steel mesh, canvas reinforced rubber, rubber composites, and other durable materials that do not prematurely fatigue. The spoiler attached at the trailing edges of blades have free edges exhibits a non-repeating pattern of feather-like projections that collectively break up the vortex formed by blade rotation by providing clean air for each successive blade. The blade efficiency is also increased by using spoiler. This paper addresses the use of spoiler and comparison of noise level of rotor blades with or without spoiler.
{"title":"Noise reduction of helicopter rotor blades by using spoiler","authors":"M. T. Islam, M. Rabbi, M. Uddin","doi":"10.1063/1.5115885","DOIUrl":"https://doi.org/10.1063/1.5115885","url":null,"abstract":"Noise has always been a major disturbance for every living creature. Noise pollution is, thus, a threat to environmental pollution too. The noise created by a helicopter draws a great contribution to the noise pollution. Reducing the noise that creates from helicopter rotor blades, tail rotors, engine etc. is a one step closer to this crisis. Helicopter noise reduction is a topic of research into designing helicopters which can be operated more quietly. The major source of the noise come from the rotor blade vortex interaction. By attaching spoiler in the helicopter main rotor blades and tail rotors reduce the noise and silence the operation. The spoiler is made of supple, resilient, and durable non-ferrous material, such as rubber, a rubber like material, plastic, rubber-impregnated with thin steel mesh, canvas reinforced rubber, rubber composites, and other durable materials that do not prematurely fatigue. The spoiler attached at the trailing edges of blades have free edges exhibits a non-repeating pattern of feather-like projections that collectively break up the vortex formed by blade rotation by providing clean air for each successive blade. The blade efficiency is also increased by using spoiler. This paper addresses the use of spoiler and comparison of noise level of rotor blades with or without spoiler.","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130416465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mehnaz Urbee Jahangir, Farhana Islam, R. A. Jahan, Abdul Matin, M. Arafat
A large quantity of fish bones is dumped everyday by the food industry. It is a natural source of calcium and can be used to synthesize hydroxyapatite (HA). Considering thermal synthesis is a low cost and straightforward process, in this study, HA is synthesized by sintering cleaned fish bones at 900 °C and 1200 °C in a heating furnace. The powder obtained after sintering was characterized using a scanning electron microscope (SEM) and fourier transform infrared (FTIR) spectroscopy. SEM analysis shows that the particle size increases as the sintering temperature is increased and the particles tend to agglomerate. The shape of the particle becomes more irregular as the temperature is increased. The FTIR spectra showed absorption peaks of hydroxyl and phosphate groups in both the samples indicating the formation of HA. No peaks of the carbonate groups are present, as all the organic components are removed after sintering. However, some characteristic peaks of β-tricalciumphosphate (β-TCP) in the sample sintered at 1200 °C are observed indicating phase transformation of HA into β-TCP as the sintering temperature is increased.A large quantity of fish bones is dumped everyday by the food industry. It is a natural source of calcium and can be used to synthesize hydroxyapatite (HA). Considering thermal synthesis is a low cost and straightforward process, in this study, HA is synthesized by sintering cleaned fish bones at 900 °C and 1200 °C in a heating furnace. The powder obtained after sintering was characterized using a scanning electron microscope (SEM) and fourier transform infrared (FTIR) spectroscopy. SEM analysis shows that the particle size increases as the sintering temperature is increased and the particles tend to agglomerate. The shape of the particle becomes more irregular as the temperature is increased. The FTIR spectra showed absorption peaks of hydroxyl and phosphate groups in both the samples indicating the formation of HA. No peaks of the carbonate groups are present, as all the organic components are removed after sintering. However, some characteristic peaks of β-tricalciumphosphate (β-TCP) in the sample sint...
{"title":"Thermal synthesis of hydroxyapatite from fish bones","authors":"Mehnaz Urbee Jahangir, Farhana Islam, R. A. Jahan, Abdul Matin, M. Arafat","doi":"10.1063/1.5115963","DOIUrl":"https://doi.org/10.1063/1.5115963","url":null,"abstract":"A large quantity of fish bones is dumped everyday by the food industry. It is a natural source of calcium and can be used to synthesize hydroxyapatite (HA). Considering thermal synthesis is a low cost and straightforward process, in this study, HA is synthesized by sintering cleaned fish bones at 900 °C and 1200 °C in a heating furnace. The powder obtained after sintering was characterized using a scanning electron microscope (SEM) and fourier transform infrared (FTIR) spectroscopy. SEM analysis shows that the particle size increases as the sintering temperature is increased and the particles tend to agglomerate. The shape of the particle becomes more irregular as the temperature is increased. The FTIR spectra showed absorption peaks of hydroxyl and phosphate groups in both the samples indicating the formation of HA. No peaks of the carbonate groups are present, as all the organic components are removed after sintering. However, some characteristic peaks of β-tricalciumphosphate (β-TCP) in the sample sintered at 1200 °C are observed indicating phase transformation of HA into β-TCP as the sintering temperature is increased.A large quantity of fish bones is dumped everyday by the food industry. It is a natural source of calcium and can be used to synthesize hydroxyapatite (HA). Considering thermal synthesis is a low cost and straightforward process, in this study, HA is synthesized by sintering cleaned fish bones at 900 °C and 1200 °C in a heating furnace. The powder obtained after sintering was characterized using a scanning electron microscope (SEM) and fourier transform infrared (FTIR) spectroscopy. SEM analysis shows that the particle size increases as the sintering temperature is increased and the particles tend to agglomerate. The shape of the particle becomes more irregular as the temperature is increased. The FTIR spectra showed absorption peaks of hydroxyl and phosphate groups in both the samples indicating the formation of HA. No peaks of the carbonate groups are present, as all the organic components are removed after sintering. However, some characteristic peaks of β-tricalciumphosphate (β-TCP) in the sample sint...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133220344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Induced drag is one of the major drag forces created in the finite wing of an aircraft. It is generated due to the pressure variation of the upper and lower portion of the wing. This drag leads to more fuel consumption and reduces speed and range of an aircraft. Winglet is a wingtip device which can reduce induced drag by reducing the pressure gradient at the wingtip of the wing. Several types of winglets have been introduced so far. The primary focus of this study is to investigate the performances of different types of winglets on a straight rectangular wing at subsonic cruise condition of flight. A rectangular wing of NACA 2412 airfoil and different types of winglets are designed by SolidWorks software and the wing models are analyzed by ANSYS Fluent software. Coefficients of lift, coefficients of drag and lift to drag ratios are measured at different angle of attacks of the wing with and without the winglets. Then comparison is carried out among them. It is found that all winglet mounted wing models provide higher lift coefficients, lower drag coefficients and higher lift to drag ratios than the wing model without winglet. Moreover, raked winglet yields the best lift to drag ratio at low angle of attacks but blended winglet with 45° cant angle provides the highest lift to drag ratio at high angle of attacks.Induced drag is one of the major drag forces created in the finite wing of an aircraft. It is generated due to the pressure variation of the upper and lower portion of the wing. This drag leads to more fuel consumption and reduces speed and range of an aircraft. Winglet is a wingtip device which can reduce induced drag by reducing the pressure gradient at the wingtip of the wing. Several types of winglets have been introduced so far. The primary focus of this study is to investigate the performances of different types of winglets on a straight rectangular wing at subsonic cruise condition of flight. A rectangular wing of NACA 2412 airfoil and different types of winglets are designed by SolidWorks software and the wing models are analyzed by ANSYS Fluent software. Coefficients of lift, coefficients of drag and lift to drag ratios are measured at different angle of attacks of the wing with and without the winglets. Then comparison is carried out among them. It is found that all winglet mounted wing models p...
{"title":"Performance comparison of different winglets by CFD","authors":"Chowdhury Abid Mahmood, R. Das","doi":"10.1063/1.5115907","DOIUrl":"https://doi.org/10.1063/1.5115907","url":null,"abstract":"Induced drag is one of the major drag forces created in the finite wing of an aircraft. It is generated due to the pressure variation of the upper and lower portion of the wing. This drag leads to more fuel consumption and reduces speed and range of an aircraft. Winglet is a wingtip device which can reduce induced drag by reducing the pressure gradient at the wingtip of the wing. Several types of winglets have been introduced so far. The primary focus of this study is to investigate the performances of different types of winglets on a straight rectangular wing at subsonic cruise condition of flight. A rectangular wing of NACA 2412 airfoil and different types of winglets are designed by SolidWorks software and the wing models are analyzed by ANSYS Fluent software. Coefficients of lift, coefficients of drag and lift to drag ratios are measured at different angle of attacks of the wing with and without the winglets. Then comparison is carried out among them. It is found that all winglet mounted wing models provide higher lift coefficients, lower drag coefficients and higher lift to drag ratios than the wing model without winglet. Moreover, raked winglet yields the best lift to drag ratio at low angle of attacks but blended winglet with 45° cant angle provides the highest lift to drag ratio at high angle of attacks.Induced drag is one of the major drag forces created in the finite wing of an aircraft. It is generated due to the pressure variation of the upper and lower portion of the wing. This drag leads to more fuel consumption and reduces speed and range of an aircraft. Winglet is a wingtip device which can reduce induced drag by reducing the pressure gradient at the wingtip of the wing. Several types of winglets have been introduced so far. The primary focus of this study is to investigate the performances of different types of winglets on a straight rectangular wing at subsonic cruise condition of flight. A rectangular wing of NACA 2412 airfoil and different types of winglets are designed by SolidWorks software and the wing models are analyzed by ANSYS Fluent software. Coefficients of lift, coefficients of drag and lift to drag ratios are measured at different angle of attacks of the wing with and without the winglets. Then comparison is carried out among them. It is found that all winglet mounted wing models p...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131055840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this paper is to investigate the boundary layer flow and heat transfer of biomagnetic fluid over a stretching/shrinking sheet in the presence of magnetic dipole. We use Lie group transformation to develop similarity transformation. Using this special form of transformation namely Lie group transformation, the governing nonlinear partial differential equations are reduced into a system of couple nonlinear ordinary differential equations subject to associated boundary conditions. The reduced resulting equation are then solved numerically by using MATLAB routine boundary value problem solver bvp4c. The effects of the pertinent parameters such as ferromagnetic parameter, suction parameter, stretching parameter and momentum slip parameter on the flow field and temperature as well as skin friction coefficient and heat transfer rate are presented and discussed through graphically in this study. Results indicate that the dual solutions exits for some specific range of governing parameter. The results of the present study have been compared with those reported by previous results and found a very good agreement that supports the validity of the present analysis and the accuracy of our numerical computations.The purpose of this paper is to investigate the boundary layer flow and heat transfer of biomagnetic fluid over a stretching/shrinking sheet in the presence of magnetic dipole. We use Lie group transformation to develop similarity transformation. Using this special form of transformation namely Lie group transformation, the governing nonlinear partial differential equations are reduced into a system of couple nonlinear ordinary differential equations subject to associated boundary conditions. The reduced resulting equation are then solved numerically by using MATLAB routine boundary value problem solver bvp4c. The effects of the pertinent parameters such as ferromagnetic parameter, suction parameter, stretching parameter and momentum slip parameter on the flow field and temperature as well as skin friction coefficient and heat transfer rate are presented and discussed through graphically in this study. Results indicate that the dual solutions exits for some specific range of governing parameter. The resul...
{"title":"Biomagnetic fluid flow past a stretching/shrinking sheet with slip conditions using lie group analysis","authors":"M. G. Murtaza, E. Tzirtzilakis, M. Ferdows","doi":"10.1063/1.5115892","DOIUrl":"https://doi.org/10.1063/1.5115892","url":null,"abstract":"The purpose of this paper is to investigate the boundary layer flow and heat transfer of biomagnetic fluid over a stretching/shrinking sheet in the presence of magnetic dipole. We use Lie group transformation to develop similarity transformation. Using this special form of transformation namely Lie group transformation, the governing nonlinear partial differential equations are reduced into a system of couple nonlinear ordinary differential equations subject to associated boundary conditions. The reduced resulting equation are then solved numerically by using MATLAB routine boundary value problem solver bvp4c. The effects of the pertinent parameters such as ferromagnetic parameter, suction parameter, stretching parameter and momentum slip parameter on the flow field and temperature as well as skin friction coefficient and heat transfer rate are presented and discussed through graphically in this study. Results indicate that the dual solutions exits for some specific range of governing parameter. The results of the present study have been compared with those reported by previous results and found a very good agreement that supports the validity of the present analysis and the accuracy of our numerical computations.The purpose of this paper is to investigate the boundary layer flow and heat transfer of biomagnetic fluid over a stretching/shrinking sheet in the presence of magnetic dipole. We use Lie group transformation to develop similarity transformation. Using this special form of transformation namely Lie group transformation, the governing nonlinear partial differential equations are reduced into a system of couple nonlinear ordinary differential equations subject to associated boundary conditions. The reduced resulting equation are then solved numerically by using MATLAB routine boundary value problem solver bvp4c. The effects of the pertinent parameters such as ferromagnetic parameter, suction parameter, stretching parameter and momentum slip parameter on the flow field and temperature as well as skin friction coefficient and heat transfer rate are presented and discussed through graphically in this study. Results indicate that the dual solutions exits for some specific range of governing parameter. The resul...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"200 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134072015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cooling towers have been widely used to dissipate heat by reducing temperature of hot water steam from heat sources to heat sink. However, the effectiveness of cooling tower depends on flow rates of air and water and water temperature. Hence, heat transfer process is very important since the heat comes from steam after spinning turbine must be removed otherwise the system will collapse due to overheating. Nanofluids are important coolant which provide new opportunities in excellent heat transfer performance, thus they can be regarded as the next-generation heat transfer fluids. The present study examined the effects of water and nanofluids as coolants on heat transfer coefficient, heat transfer rate, pressure drop and pumping power in the counter flow induced draft cooling tower and finding out the effect of adding toner as nanofluid to circulating cooling fluids. This was done by establishing and modifying experimental set up constructing computer program and varying the quality of circulating fluids by adding together at different ratio. Counter flow induced draft cooling tower and computer program give the various data required for calculation. From the result obtained a comparative study on terms of tower characteristics, water to air flow ratio (L/G), efficiency, range, percentage of make-up water and evaporation heat loss are presented in graphical form. It is estimated that efficiency and range increase by 8% & 4°c in average respectively. Furthermore, efficiency varies from 28.5 % to 39.15 % in case of cooling tower with water whereas with ink it is 42.55 % to 58.42 %which indicates the good performance of the developed system.Cooling towers have been widely used to dissipate heat by reducing temperature of hot water steam from heat sources to heat sink. However, the effectiveness of cooling tower depends on flow rates of air and water and water temperature. Hence, heat transfer process is very important since the heat comes from steam after spinning turbine must be removed otherwise the system will collapse due to overheating. Nanofluids are important coolant which provide new opportunities in excellent heat transfer performance, thus they can be regarded as the next-generation heat transfer fluids. The present study examined the effects of water and nanofluids as coolants on heat transfer coefficient, heat transfer rate, pressure drop and pumping power in the counter flow induced draft cooling tower and finding out the effect of adding toner as nanofluid to circulating cooling fluids. This was done by establishing and modifying experimental set up constructing computer program and varying the quality of circulating fluids by ...
{"title":"Experimental analysis on heat transfer performance of cooling tower with nanofluid","authors":"Habibur Rahman, A. Hossain, M. Ali","doi":"10.1063/1.5115918","DOIUrl":"https://doi.org/10.1063/1.5115918","url":null,"abstract":"Cooling towers have been widely used to dissipate heat by reducing temperature of hot water steam from heat sources to heat sink. However, the effectiveness of cooling tower depends on flow rates of air and water and water temperature. Hence, heat transfer process is very important since the heat comes from steam after spinning turbine must be removed otherwise the system will collapse due to overheating. Nanofluids are important coolant which provide new opportunities in excellent heat transfer performance, thus they can be regarded as the next-generation heat transfer fluids. The present study examined the effects of water and nanofluids as coolants on heat transfer coefficient, heat transfer rate, pressure drop and pumping power in the counter flow induced draft cooling tower and finding out the effect of adding toner as nanofluid to circulating cooling fluids. This was done by establishing and modifying experimental set up constructing computer program and varying the quality of circulating fluids by adding together at different ratio. Counter flow induced draft cooling tower and computer program give the various data required for calculation. From the result obtained a comparative study on terms of tower characteristics, water to air flow ratio (L/G), efficiency, range, percentage of make-up water and evaporation heat loss are presented in graphical form. It is estimated that efficiency and range increase by 8% & 4°c in average respectively. Furthermore, efficiency varies from 28.5 % to 39.15 % in case of cooling tower with water whereas with ink it is 42.55 % to 58.42 %which indicates the good performance of the developed system.Cooling towers have been widely used to dissipate heat by reducing temperature of hot water steam from heat sources to heat sink. However, the effectiveness of cooling tower depends on flow rates of air and water and water temperature. Hence, heat transfer process is very important since the heat comes from steam after spinning turbine must be removed otherwise the system will collapse due to overheating. Nanofluids are important coolant which provide new opportunities in excellent heat transfer performance, thus they can be regarded as the next-generation heat transfer fluids. The present study examined the effects of water and nanofluids as coolants on heat transfer coefficient, heat transfer rate, pressure drop and pumping power in the counter flow induced draft cooling tower and finding out the effect of adding toner as nanofluid to circulating cooling fluids. This was done by establishing and modifying experimental set up constructing computer program and varying the quality of circulating fluids by ...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123983593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Pervez, Priyo Nath Roy, H. Ahamed, Md. Manirul Islam, C. Oddo, G. Ciuti, P. Dario
Industrial robots are often used in positioning and material handling purposes. Due to low accuracy and high stiffness, the researchers are more concern on to improve in control operation like high accuracy trajectory tracking. This paper presents a real time position control of 6 DOF Mitsubishi robot and deals with Cartesian parameters monitoring and controlling. Feed forward control method is used. The robot movement is on Cartesian co-ordinate mode and operates from remote computer. These Cartesian parameters have to be continuously monitored and control in real time by the user. The Virtual Instrument is created using LabVIEW software which creates Graphical Control and monitoring system. An Ethernet User Datagram Protocol (UDP) is used for developing an online transmission process between client and server. This helps in easy and fast transmission of data in form of messages between the client PC(s) and server robot. With the help of internet protocol, client provides the value of set point according to which the control actions are taken by the server. Finally, experimental validation is performed using a Mitsubishi robot to verify the correctness and accuracy of the approach.
工业机器人常用于定位和物料搬运目的。由于精度低、刚度大，如何提高控制操作精度，如高精度轨迹跟踪成为研究人员关注的问题。介绍了三菱六自由度机器人的实时位置控制，并对其笛卡尔参数进行了监测和控制。采用前馈控制方法。机器人运动采用直角坐标模式，通过远程计算机进行操作。这些笛卡尔参数必须由用户持续监测和实时控制。利用LabVIEW软件实现了虚拟仪器的图形化控制和监控系统。UDP (Ethernet User Datagram Protocol)协议用于开发客户端和服务器之间的在线传输过程。这有助于在客户端PC和服务器机器人之间以消息的形式轻松快速地传输数据。在互联网协议的帮助下，客户端提供设定值，服务器根据设定值采取控制动作。最后，利用三菱机器人进行了实验验证，验证了该方法的正确性和准确性。
{"title":"Real time position control of industrial robot over ethernet based communication framework","authors":"M. Pervez, Priyo Nath Roy, H. Ahamed, Md. Manirul Islam, C. Oddo, G. Ciuti, P. Dario","doi":"10.1063/1.5115966","DOIUrl":"https://doi.org/10.1063/1.5115966","url":null,"abstract":"Industrial robots are often used in positioning and material handling purposes. Due to low accuracy and high stiffness, the researchers are more concern on to improve in control operation like high accuracy trajectory tracking. This paper presents a real time position control of 6 DOF Mitsubishi robot and deals with Cartesian parameters monitoring and controlling. Feed forward control method is used. The robot movement is on Cartesian co-ordinate mode and operates from remote computer. These Cartesian parameters have to be continuously monitored and control in real time by the user. The Virtual Instrument is created using LabVIEW software which creates Graphical Control and monitoring system. An Ethernet User Datagram Protocol (UDP) is used for developing an online transmission process between client and server. This helps in easy and fast transmission of data in form of messages between the client PC(s) and server robot. With the help of internet protocol, client provides the value of set point according to which the control actions are taken by the server. Finally, experimental validation is performed using a Mitsubishi robot to verify the correctness and accuracy of the approach.","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128931607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md. Abdus Salam, V. Deshpande, S. Panday, N. Khan, M. Ali
The NACA0021 being a thick airfoil, possesses soft stall behavior with moderate maximum coefficient of lift (clmax). The present study focusses to improve aerodynamic performance using the moving surface boundary control. The modifications to airfoil include a rotating leading edge cylinder with airfoil aft body. The leading edge rotating cylinder injects momentum in top surface boundary layer thereby, keeping the flow attached in the otherwise adverse pressure gradient. The attached flow over top surface shall contribute to improve the airfoil aerodynamic performance in terms of lift, drag and stall angle. The present computational study focusses on modified airfoil performance for varying velocity ratios (i.e. ratio of tangential velocity of rotating cylinder and free stream velocity) between 0.0 and 1.78 at different airfoil angles of attack. The computational study clearly highlights improvement in modified airfoil aerodynamic performance in terms of coefficient of lift, drag, stall angle and clmax even at velocity ratios less than 1.0. The lift and drag characteristics of modified airfoil are found to be superior to base airfoil for velocity ratios beyond 0.356 and 0.7 respectively. The stall angle of attack for modified airfoil is also seen to increase linearly with velocity ratio. The stall angle of attack nearly doubles from 10° for stationary leading edge to 19° for velocity ratio of 1.78. The extent of momentum injection in boundary layer with varying cylinder speed is analysed by comparing the coefficient of pressure plots. The aerodynamic performance improvement thus achieved by momentum injection by low cost and practically feasible leading edge rotating cylinder in NACA 0021 promises its possible utilization for varied applications i.e. for low speed aircraft wing, wind turbine blades and hydrofoils.The NACA0021 being a thick airfoil, possesses soft stall behavior with moderate maximum coefficient of lift (clmax). The present study focusses to improve aerodynamic performance using the moving surface boundary control. The modifications to airfoil include a rotating leading edge cylinder with airfoil aft body. The leading edge rotating cylinder injects momentum in top surface boundary layer thereby, keeping the flow attached in the otherwise adverse pressure gradient. The attached flow over top surface shall contribute to improve the airfoil aerodynamic performance in terms of lift, drag and stall angle. The present computational study focusses on modified airfoil performance for varying velocity ratios (i.e. ratio of tangential velocity of rotating cylinder and free stream velocity) between 0.0 and 1.78 at different airfoil angles of attack. The computational study clearly highlights improvement in modified airfoil aerodynamic performance in terms of coefficient of lift, drag, stall angle and clmax ev...
{"title":"Improvement in aerodynamic performance of NACA0021 airfoil using moving surface boundary layer: A computational study","authors":"Md. Abdus Salam, V. Deshpande, S. Panday, N. Khan, M. Ali","doi":"10.1063/1.5115903","DOIUrl":"https://doi.org/10.1063/1.5115903","url":null,"abstract":"The NACA0021 being a thick airfoil, possesses soft stall behavior with moderate maximum coefficient of lift (clmax). The present study focusses to improve aerodynamic performance using the moving surface boundary control. The modifications to airfoil include a rotating leading edge cylinder with airfoil aft body. The leading edge rotating cylinder injects momentum in top surface boundary layer thereby, keeping the flow attached in the otherwise adverse pressure gradient. The attached flow over top surface shall contribute to improve the airfoil aerodynamic performance in terms of lift, drag and stall angle. The present computational study focusses on modified airfoil performance for varying velocity ratios (i.e. ratio of tangential velocity of rotating cylinder and free stream velocity) between 0.0 and 1.78 at different airfoil angles of attack. The computational study clearly highlights improvement in modified airfoil aerodynamic performance in terms of coefficient of lift, drag, stall angle and clmax even at velocity ratios less than 1.0. The lift and drag characteristics of modified airfoil are found to be superior to base airfoil for velocity ratios beyond 0.356 and 0.7 respectively. The stall angle of attack for modified airfoil is also seen to increase linearly with velocity ratio. The stall angle of attack nearly doubles from 10° for stationary leading edge to 19° for velocity ratio of 1.78. The extent of momentum injection in boundary layer with varying cylinder speed is analysed by comparing the coefficient of pressure plots. The aerodynamic performance improvement thus achieved by momentum injection by low cost and practically feasible leading edge rotating cylinder in NACA 0021 promises its possible utilization for varied applications i.e. for low speed aircraft wing, wind turbine blades and hydrofoils.The NACA0021 being a thick airfoil, possesses soft stall behavior with moderate maximum coefficient of lift (clmax). The present study focusses to improve aerodynamic performance using the moving surface boundary control. The modifications to airfoil include a rotating leading edge cylinder with airfoil aft body. The leading edge rotating cylinder injects momentum in top surface boundary layer thereby, keeping the flow attached in the otherwise adverse pressure gradient. The attached flow over top surface shall contribute to improve the airfoil aerodynamic performance in terms of lift, drag and stall angle. The present computational study focusses on modified airfoil performance for varying velocity ratios (i.e. ratio of tangential velocity of rotating cylinder and free stream velocity) between 0.0 and 1.78 at different airfoil angles of attack. The computational study clearly highlights improvement in modified airfoil aerodynamic performance in terms of coefficient of lift, drag, stall angle and clmax ev...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"297 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120848626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For modern supersonic vehicles, thrust vector control is a conspicuous prerequisite to accomplish high performance aerospace applications. Thrust vector control chiefly falls into a few classifications, for example, mechanical thrust vector control and shock vector control. Shock vector control is outstanding amongst other approaches to achieve this thrust vector control. A bypass mass injection is used to generate shock vectoring in a planar supersonic Convergent-Divergent (CD) propulsion nozzle in this study and a 10×10 square mm bypass channel was used for the injection. This bypass mass injection is kept perpendicular at the diverging section of the studied nozzle. Overexpanded nozzle flow is achieved by carrying out the investigation at Nozzle Pressure Ratio (NPR) of 3.0. The flow conditions and size of the square injection channel ensures the bypass mass flow ratio around 5%. Reynolds-Averaged-Navier-Stokes (RANS) equations with k-ω SST turbulence model have been applied through numerical computations to capture the three-dimensional steady characteristics of the flow field. Results show that the shock structure becomes asymmetric due to the bypass mass injection along with the formation of recirculation zone near the bypass mass injection. Moreover, a considerable thrust vectoring can be achieved due to the asymmetric velocity distribution at the exit plane.For modern supersonic vehicles, thrust vector control is a conspicuous prerequisite to accomplish high performance aerospace applications. Thrust vector control chiefly falls into a few classifications, for example, mechanical thrust vector control and shock vector control. Shock vector control is outstanding amongst other approaches to achieve this thrust vector control. A bypass mass injection is used to generate shock vectoring in a planar supersonic Convergent-Divergent (CD) propulsion nozzle in this study and a 10×10 square mm bypass channel was used for the injection. This bypass mass injection is kept perpendicular at the diverging section of the studied nozzle. Overexpanded nozzle flow is achieved by carrying out the investigation at Nozzle Pressure Ratio (NPR) of 3.0. The flow conditions and size of the square injection channel ensures the bypass mass flow ratio around 5%. Reynolds-Averaged-Navier-Stokes (RANS) equations with k-ω SST turbulence model have been applied through numerical computatio...
对于现代超声速飞行器来说，推力矢量控制是实现高性能航天应用的重要前提。推力矢量控制主要分为机械推力矢量控制和冲击矢量控制。在实现推力矢量控制的其他方法中，冲击矢量控制是突出的。在平面超声速会聚发散推进喷管中，采用旁通质量喷射来产生激波矢量，并采用10×10平方mm的旁通通道进行喷射。在所研究的喷管的发散部分保持这种旁路质量注入的垂直。在喷嘴压力比(NPR)为3.0时，研究了喷嘴过膨胀流动。方形注射通道的流动条件和尺寸保证了旁通质量流量比在5%左右。采用k-ω海温湍流模型的reynolds - average - navier - stokes (RANS)方程，通过数值计算捕捉了流场的三维稳态特征。结果表明:由于旁通质量注入，激波结构变得不对称，并在旁通质量注入附近形成再循环区;此外，由于出口平面的速度分布不对称，可以实现相当大的推力矢量。对于现代超声速飞行器来说，推力矢量控制是实现高性能航天应用的重要前提。推力矢量控制主要分为机械推力矢量控制和冲击矢量控制。在实现推力矢量控制的其他方法中，冲击矢量控制是突出的。在平面超声速会聚发散推进喷管中，采用旁通质量喷射来产生激波矢量，并采用10×10平方mm的旁通通道进行喷射。在所研究的喷管的发散部分保持这种旁路质量注入的垂直。在喷嘴压力比(NPR)为3.0时，研究了喷嘴过膨胀流动。方形注射通道的流动条件和尺寸保证了旁通质量流量比在5%左右。本文通过数值计算应用了具有k-ω海温湍流模型的reynolds - average - navier - stokes (RANS)方程。
{"title":"3D computational study of thrust vectoring using bypass mass injection in a propulsion nozzle","authors":"Muhammad Abdun Nafi, A. Hasan","doi":"10.1063/1.5115900","DOIUrl":"https://doi.org/10.1063/1.5115900","url":null,"abstract":"For modern supersonic vehicles, thrust vector control is a conspicuous prerequisite to accomplish high performance aerospace applications. Thrust vector control chiefly falls into a few classifications, for example, mechanical thrust vector control and shock vector control. Shock vector control is outstanding amongst other approaches to achieve this thrust vector control. A bypass mass injection is used to generate shock vectoring in a planar supersonic Convergent-Divergent (CD) propulsion nozzle in this study and a 10×10 square mm bypass channel was used for the injection. This bypass mass injection is kept perpendicular at the diverging section of the studied nozzle. Overexpanded nozzle flow is achieved by carrying out the investigation at Nozzle Pressure Ratio (NPR) of 3.0. The flow conditions and size of the square injection channel ensures the bypass mass flow ratio around 5%. Reynolds-Averaged-Navier-Stokes (RANS) equations with k-ω SST turbulence model have been applied through numerical computations to capture the three-dimensional steady characteristics of the flow field. Results show that the shock structure becomes asymmetric due to the bypass mass injection along with the formation of recirculation zone near the bypass mass injection. Moreover, a considerable thrust vectoring can be achieved due to the asymmetric velocity distribution at the exit plane.For modern supersonic vehicles, thrust vector control is a conspicuous prerequisite to accomplish high performance aerospace applications. Thrust vector control chiefly falls into a few classifications, for example, mechanical thrust vector control and shock vector control. Shock vector control is outstanding amongst other approaches to achieve this thrust vector control. A bypass mass injection is used to generate shock vectoring in a planar supersonic Convergent-Divergent (CD) propulsion nozzle in this study and a 10×10 square mm bypass channel was used for the injection. This bypass mass injection is kept perpendicular at the diverging section of the studied nozzle. Overexpanded nozzle flow is achieved by carrying out the investigation at Nozzle Pressure Ratio (NPR) of 3.0. The flow conditions and size of the square injection channel ensures the bypass mass flow ratio around 5%. Reynolds-Averaged-Navier-Stokes (RANS) equations with k-ω SST turbulence model have been applied through numerical computatio...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121685950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90° bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS and Casson model predicts low WSS at all inlet velocity conditions which is indifferent from other non-Newtonian models. In moderate and high flow rates all the models are indistinguishable except in low flow rate. In case of increasing flow rate, Carreau and Herschel-Bulkley model demonstrate decreasing the value of IG thus acting as Newtonian fluid except for Casson and non-Newtonian power law. In conclusion, Carreau and Herschel-Bulkley models can be used for bifurcating LCA rather than Casson and non-Newtonian power law as they are very much sensitive to the non-Newtonian behavior of blood. As Herschel-Bulkley model predicts lower IG values than the Carreau model thus Carreau is more appropriate as blood viscosity model for bifurcating LCA.A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90° bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS and Casson model predicts low WSS at all inlet velocity conditions which is indifferent from other non-Newtonian models. In moderate and high flow rates all the models are indistinguishable except in low flow rate. In c...
{"title":"Computational analysis of left coronary bifurcating artery using different blood rheological models","authors":"Fahmida S. Laboni, Foysal Rabbi, M. Arafat","doi":"10.1063/1.5115933","DOIUrl":"https://doi.org/10.1063/1.5115933","url":null,"abstract":"A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90° bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS and Casson model predicts low WSS at all inlet velocity conditions which is indifferent from other non-Newtonian models. In moderate and high flow rates all the models are indistinguishable except in low flow rate. In case of increasing flow rate, Carreau and Herschel-Bulkley model demonstrate decreasing the value of IG thus acting as Newtonian fluid except for Casson and non-Newtonian power law. In conclusion, Carreau and Herschel-Bulkley models can be used for bifurcating LCA rather than Casson and non-Newtonian power law as they are very much sensitive to the non-Newtonian behavior of blood. As Herschel-Bulkley model predicts lower IG values than the Carreau model thus Carreau is more appropriate as blood viscosity model for bifurcating LCA.A numerical study is performed to investigate hemodynamic factors using Newtonian and non-Newtonian blood viscosity models under pulsatile blood flow condition. In this study, simulation is done on 90° bifurcating left coronary artery (LCA) by using Computational Fluid Dynamics (CFD). Comparative analysis is performed among one Newtonian and four non-Newtonian blood viscosity models. Wall shear stress (WSS), oscillatory shear index (OSI), global non-Newtonian importance factor (IG) and time-averaged wall shear stress (TAWSS) are shown at a specific point during the cardiac cycle. It is noticed that the pattern of WSS distribution is mostly consistent in all the models. However, the difference is only in the magnitude of WSS. For low inlet velocity, non-Newtonian power law predicts high WSS and Casson model predicts low WSS at all inlet velocity conditions which is indifferent from other non-Newtonian models. In moderate and high flow rates all the models are indistinguishable except in low flow rate. In c...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121802189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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