The ground surface temperature changes with the diurnal cycle of solar radiation and ambient air temperature. However, the amplitude of the ground temperature variation diminishes with the increase of the depth of the ground and after a certain depth of the ground, it becomes almost constant, where is termed “undisturbed ground temperature (UGT)”. At this depth, the seasonal changes of solar radiation and ambient air temperature changes will no longer affect onground temperature. It is one of the important parameters for designing of the ground heat exchangersand building energy analyses. In this study ground temperatures at various depths in Melbourne were investigated using a 40 m deep borehole instrumented with thermistors. The ground temperatures at various depths (0 m to 40 m) in Melbourne were also simulated by using three methods: Kasuda formula method, simulation (TRNSYS, Type 77), and simplified correlation (developed by Ouzzane et al. in 2015) and the results were compared with the measured data. Root mean square error (RMSE) and mean bias error (MBE) were used to validate and verify the methods. It was found that the estimated ground temperatures at 2, 21, and 40 m depths by Kasuda formula method and simulation (TRNSYS)have the same trends as that of the measured data. The measured annual temperatures of ground at 2 m depth were between 14.7 °C and 19.8 °C, while the temperature at 21 m and 40 m depths remained almost constant. RMSE and MBEof the simulation (TRNSYS, Type 77) were found to be 1.39°C, and -1.39°C respectively compared to measured data at 21 m depth. Based on these values, we conclude that simulation (TRNSYS, Type 77) can reliably predict the ground temperature for the selected sitein Melbourne.The ground surface temperature changes with the diurnal cycle of solar radiation and ambient air temperature. However, the amplitude of the ground temperature variation diminishes with the increase of the depth of the ground and after a certain depth of the ground, it becomes almost constant, where is termed “undisturbed ground temperature (UGT)”. At this depth, the seasonal changes of solar radiation and ambient air temperature changes will no longer affect onground temperature. It is one of the important parameters for designing of the ground heat exchangersand building energy analyses. In this study ground temperatures at various depths in Melbourne were investigated using a 40 m deep borehole instrumented with thermistors. The ground temperatures at various depths (0 m to 40 m) in Melbourne were also simulated by using three methods: Kasuda formula method, simulation (TRNSYS, Type 77), and simplified correlation (developed by Ouzzane et al. in 2015) and the results were compared with the measured data...
地表温度随太阳辐射和环境气温的日循环而变化。但地温变化幅度随地表深度的增加而减小，达到一定深度后基本保持不变，称为“无扰动地温”。在这个深度，太阳辐射的季节变化和周围空气温度的变化将不再影响地面温度。它是地下换热器设计和建筑能耗分析的重要参数之一。在这项研究中，使用40米深的热敏电阻测量了墨尔本不同深度的地温。采用Kasuda公式法、模拟(TRNSYS, Type 77)和简化相关(Ouzzane et al. 2015)三种方法对墨尔本不同深度(0 m ~ 40 m)的地温进行模拟，并与实测数据进行对比。采用均方根误差(RMSE)和平均偏差误差(MBE)对方法进行验证和验证。结果表明，用Kasuda公式法和TRNSYS模拟得到的2、21和40 m深度的地温值与实测数据具有相同的变化趋势。2 m深度地表年平均温度在14.7 ~ 19.8℃之间，21 m和40 m深度地表年平均温度基本保持不变。与21 m深度的实测数据相比，模拟(TRNSYS, Type 77)的RMSE和mbec分别为1.39°C和-1.39°C。基于这些值，我们得出结论，模拟(TRNSYS, Type 77)可以可靠地预测墨尔本选定地点的地温。地表温度随太阳辐射和环境气温的日循环而变化。但地温变化幅度随地表深度的增加而减小，达到一定深度后基本保持不变，称为“无扰动地温”。在这个深度，太阳辐射的季节变化和周围空气温度的变化将不再影响地面温度。它是地下换热器设计和建筑能耗分析的重要参数之一。在这项研究中，使用40米深的热敏电阻测量了墨尔本不同深度的地温。采用Kasuda公式法、模拟(TRNSYS, Type 77)和简化相关(Ouzzane et al. 2015)三种方法对墨尔本不同深度(0 m ~ 40 m)的地温进行了模拟，并将结果与实测数据进行了对比。
{"title":"Undisturbed ground temperature in Melbourne","authors":"Sheikh Khaleduzzaman Shah, L. Aye, B. Rismanchi","doi":"10.1063/1.5115928","DOIUrl":"https://doi.org/10.1063/1.5115928","url":null,"abstract":"The ground surface temperature changes with the diurnal cycle of solar radiation and ambient air temperature. However, the amplitude of the ground temperature variation diminishes with the increase of the depth of the ground and after a certain depth of the ground, it becomes almost constant, where is termed “undisturbed ground temperature (UGT)”. At this depth, the seasonal changes of solar radiation and ambient air temperature changes will no longer affect onground temperature. It is one of the important parameters for designing of the ground heat exchangersand building energy analyses. In this study ground temperatures at various depths in Melbourne were investigated using a 40 m deep borehole instrumented with thermistors. The ground temperatures at various depths (0 m to 40 m) in Melbourne were also simulated by using three methods: Kasuda formula method, simulation (TRNSYS, Type 77), and simplified correlation (developed by Ouzzane et al. in 2015) and the results were compared with the measured data. Root mean square error (RMSE) and mean bias error (MBE) were used to validate and verify the methods. It was found that the estimated ground temperatures at 2, 21, and 40 m depths by Kasuda formula method and simulation (TRNSYS)have the same trends as that of the measured data. The measured annual temperatures of ground at 2 m depth were between 14.7 °C and 19.8 °C, while the temperature at 21 m and 40 m depths remained almost constant. RMSE and MBEof the simulation (TRNSYS, Type 77) were found to be 1.39°C, and -1.39°C respectively compared to measured data at 21 m depth. Based on these values, we conclude that simulation (TRNSYS, Type 77) can reliably predict the ground temperature for the selected sitein Melbourne.The ground surface temperature changes with the diurnal cycle of solar radiation and ambient air temperature. However, the amplitude of the ground temperature variation diminishes with the increase of the depth of the ground and after a certain depth of the ground, it becomes almost constant, where is termed “undisturbed ground temperature (UGT)”. At this depth, the seasonal changes of solar radiation and ambient air temperature changes will no longer affect onground temperature. It is one of the important parameters for designing of the ground heat exchangersand building energy analyses. In this study ground temperatures at various depths in Melbourne were investigated using a 40 m deep borehole instrumented with thermistors. The ground temperatures at various depths (0 m to 40 m) in Melbourne were also simulated by using three methods: Kasuda formula method, simulation (TRNSYS, Type 77), and simplified correlation (developed by Ouzzane et al. in 2015) and the results were compared with the measured data...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"11 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":"114073133","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. Noman, M. Tusar, K. Uddin, Faruk Uddin, S. Paul, M.M. Rahman
Unmanned Underwater Vehicle (UUV) is vehicle that is controlled by human or automatically and operated underwater for executing different task. For effective maneuverability, the hydro dynamic performance of the UUV has to be evaluated or predicted before employed in the workspace. CFD software was used in this study. The model was designed in CAD software. As the UUV was symmetric about XY plane axis, so half of the UUV body was simulated. It is seen that negative lift is present for all velocity at zero angle of attack. This is a great finding of the study. This is due to conning tower which is located upon the top surface. As the angle of attack change from negative to more positive value, negative lift shifts more quickly to positive value for higher velocity. At higher velocity Lift coefficient does not change so much with velocity. Same amount to drag experience by the UUV for different diving angle. A lot of variation was found with velocity as expected, since drag is proportional to the square of velocity. CD is almost same for all diving angle for different velocity, except for lowest velocity 0.2m/s. Further investigation is needed for this large variation. From lift curve it is seen that for 0.2m/s and 0.4m/s velocity almost always creating negative lift for all diving angle. But for 0.6m/s lift was positive. A considerable difference captured in CL at 0.2m/s and 1m/s for zero diving angle. This is an important finding of the study. Other Cl are not much differing for different diving angle. Pitching moment does not vary with diving angle for constant velocity. But considerable change found in velocity difference as expected. Pitching moment coefficients does not change above 5° diving angle for different velocity. But at low diving angle up to 5° the change is considerable.Unmanned Underwater Vehicle (UUV) is vehicle that is controlled by human or automatically and operated underwater for executing different task. For effective maneuverability, the hydro dynamic performance of the UUV has to be evaluated or predicted before employed in the workspace. CFD software was used in this study. The model was designed in CAD software. As the UUV was symmetric about XY plane axis, so half of the UUV body was simulated. It is seen that negative lift is present for all velocity at zero angle of attack. This is a great finding of the study. This is due to conning tower which is located upon the top surface. As the angle of attack change from negative to more positive value, negative lift shifts more quickly to positive value for higher velocity. At higher velocity Lift coefficient does not change so much with velocity. Same amount to drag experience by the UUV for different diving angle. A lot of variation was found with velocity as expected, since drag is proportional to the square of ...
{"title":"Performance analysis of an unmanned under water vehicle using CFD technique","authors":"A. Noman, M. Tusar, K. Uddin, Faruk Uddin, S. Paul, M.M. Rahman","doi":"10.1063/1.5115886","DOIUrl":"https://doi.org/10.1063/1.5115886","url":null,"abstract":"Unmanned Underwater Vehicle (UUV) is vehicle that is controlled by human or automatically and operated underwater for executing different task. For effective maneuverability, the hydro dynamic performance of the UUV has to be evaluated or predicted before employed in the workspace. CFD software was used in this study. The model was designed in CAD software. As the UUV was symmetric about XY plane axis, so half of the UUV body was simulated. It is seen that negative lift is present for all velocity at zero angle of attack. This is a great finding of the study. This is due to conning tower which is located upon the top surface. As the angle of attack change from negative to more positive value, negative lift shifts more quickly to positive value for higher velocity. At higher velocity Lift coefficient does not change so much with velocity. Same amount to drag experience by the UUV for different diving angle. A lot of variation was found with velocity as expected, since drag is proportional to the square of velocity. CD is almost same for all diving angle for different velocity, except for lowest velocity 0.2m/s. Further investigation is needed for this large variation. From lift curve it is seen that for 0.2m/s and 0.4m/s velocity almost always creating negative lift for all diving angle. But for 0.6m/s lift was positive. A considerable difference captured in CL at 0.2m/s and 1m/s for zero diving angle. This is an important finding of the study. Other Cl are not much differing for different diving angle. Pitching moment does not vary with diving angle for constant velocity. But considerable change found in velocity difference as expected. Pitching moment coefficients does not change above 5° diving angle for different velocity. But at low diving angle up to 5° the change is considerable.Unmanned Underwater Vehicle (UUV) is vehicle that is controlled by human or automatically and operated underwater for executing different task. For effective maneuverability, the hydro dynamic performance of the UUV has to be evaluated or predicted before employed in the workspace. CFD software was used in this study. The model was designed in CAD software. As the UUV was symmetric about XY plane axis, so half of the UUV body was simulated. It is seen that negative lift is present for all velocity at zero angle of attack. This is a great finding of the study. This is due to conning tower which is located upon the top surface. As the angle of attack change from negative to more positive value, negative lift shifts more quickly to positive value for higher velocity. At higher velocity Lift coefficient does not change so much with velocity. Same amount to drag experience by the UUV for different diving angle. A lot of variation was found with velocity as expected, since drag is proportional to the square of ...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"11 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":"121881412","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}
South Asia makes up nearly one quarter of the world’s population. Yet its per capita yearly electric power consumption is the 2nd lowest (just above the Sub Saharan Africa) compared to any regions and sub regions in the world. Access to power and meagre per capita consumption make South Asia one of the poorest regions in the world based on economic and human development indices. Limited indigenous energy resources of individual nations in South Asia are not enough to generate adequate power for rapid industrialization, economic and social development. Moreover, the availability of limited indigenous energy resources varies among South Asian nations. The power demand and supply also differ due to seasonal variability. With rapidly rising power demand in all South Asian countries, there are opportunities for cooperation and optimization of available generated power through cross-border power trade. This paper reviews power present generation in South Asia and highlights the potential for cross border power trade to boast regional economic development and prosperity.South Asia makes up nearly one quarter of the world’s population. Yet its per capita yearly electric power consumption is the 2nd lowest (just above the Sub Saharan Africa) compared to any regions and sub regions in the world. Access to power and meagre per capita consumption make South Asia one of the poorest regions in the world based on economic and human development indices. Limited indigenous energy resources of individual nations in South Asia are not enough to generate adequate power for rapid industrialization, economic and social development. Moreover, the availability of limited indigenous energy resources varies among South Asian nations. The power demand and supply also differ due to seasonal variability. With rapidly rising power demand in all South Asian countries, there are opportunities for cooperation and optimization of available generated power through cross-border power trade. This paper reviews power present generation in South Asia and highlights the potential for cross border power ...
{"title":"South Asia’s power generation and cross-border power trading","authors":"F. Alam, S. Ahsan, Q. Alam","doi":"10.1063/1.5115970","DOIUrl":"https://doi.org/10.1063/1.5115970","url":null,"abstract":"South Asia makes up nearly one quarter of the world’s population. Yet its per capita yearly electric power consumption is the 2nd lowest (just above the Sub Saharan Africa) compared to any regions and sub regions in the world. Access to power and meagre per capita consumption make South Asia one of the poorest regions in the world based on economic and human development indices. Limited indigenous energy resources of individual nations in South Asia are not enough to generate adequate power for rapid industrialization, economic and social development. Moreover, the availability of limited indigenous energy resources varies among South Asian nations. The power demand and supply also differ due to seasonal variability. With rapidly rising power demand in all South Asian countries, there are opportunities for cooperation and optimization of available generated power through cross-border power trade. This paper reviews power present generation in South Asia and highlights the potential for cross border power trade to boast regional economic development and prosperity.South Asia makes up nearly one quarter of the world’s population. Yet its per capita yearly electric power consumption is the 2nd lowest (just above the Sub Saharan Africa) compared to any regions and sub regions in the world. Access to power and meagre per capita consumption make South Asia one of the poorest regions in the world based on economic and human development indices. Limited indigenous energy resources of individual nations in South Asia are not enough to generate adequate power for rapid industrialization, economic and social development. Moreover, the availability of limited indigenous energy resources varies among South Asian nations. The power demand and supply also differ due to seasonal variability. With rapidly rising power demand in all South Asian countries, there are opportunities for cooperation and optimization of available generated power through cross-border power trade. This paper reviews power present generation in South Asia and highlights the potential for cross border power ...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"98 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":"124685258","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 dry-sliding wear and frictional behavior of a polymeric matrix material commonly used in fiber-reinforced composite applications are investigated as a function of thermal ageing temperature. More specifically, the commercially available polyester resin is used in this study to prepare disc-like samples of diameter 75mm and thickness 3mm, which are then aged isochronally at temperatures of 25°C, 75°C, 100°C and 125°C for a period of one hour. The wear test has been carried out against a high-speed carbon steel pin with a diameter of 5mm at a test load of 10N, in which the sliding distance is varied from 20m to 1450m with a sliding velocity of 0.4ms−1. The wear and frictional behavior of the polyester resin are found to be improved quite significantly when the samples are thermally treated at a temperature of around 125°C. At lower temperatures, softening of the polymeric sheet occurs due to minimum heat generation, which, in turn, results in a reduction of hardness and wear resistance. A surface investigation by scanning electron microscopic (SEM) images reveals that some casting defects are present in the form of pores in the original non-worn surfaces, whereas the worn surfaces are subjected to a resultant of severe plastic deformation and scuffing when the polyester resin samples are thermally treated at 125°C.The dry-sliding wear and frictional behavior of a polymeric matrix material commonly used in fiber-reinforced composite applications are investigated as a function of thermal ageing temperature. More specifically, the commercially available polyester resin is used in this study to prepare disc-like samples of diameter 75mm and thickness 3mm, which are then aged isochronally at temperatures of 25°C, 75°C, 100°C and 125°C for a period of one hour. The wear test has been carried out against a high-speed carbon steel pin with a diameter of 5mm at a test load of 10N, in which the sliding distance is varied from 20m to 1450m with a sliding velocity of 0.4ms−1. The wear and frictional behavior of the polyester resin are found to be improved quite significantly when the samples are thermally treated at a temperature of around 125°C. At lower temperatures, softening of the polymeric sheet occurs due to minimum heat generation, which, in turn, results in a reduction of hardness and wear resistance. A surface invest...
{"title":"Effect of thermal ageing on dry-sliding wear behavior of polymeric matrix materials used in FRC applications","authors":"F. Tabassum, R. Asekin, M. S. Kaiser, S. R. Ahmed","doi":"10.1063/1.5115961","DOIUrl":"https://doi.org/10.1063/1.5115961","url":null,"abstract":"The dry-sliding wear and frictional behavior of a polymeric matrix material commonly used in fiber-reinforced composite applications are investigated as a function of thermal ageing temperature. More specifically, the commercially available polyester resin is used in this study to prepare disc-like samples of diameter 75mm and thickness 3mm, which are then aged isochronally at temperatures of 25°C, 75°C, 100°C and 125°C for a period of one hour. The wear test has been carried out against a high-speed carbon steel pin with a diameter of 5mm at a test load of 10N, in which the sliding distance is varied from 20m to 1450m with a sliding velocity of 0.4ms−1. The wear and frictional behavior of the polyester resin are found to be improved quite significantly when the samples are thermally treated at a temperature of around 125°C. At lower temperatures, softening of the polymeric sheet occurs due to minimum heat generation, which, in turn, results in a reduction of hardness and wear resistance. A surface investigation by scanning electron microscopic (SEM) images reveals that some casting defects are present in the form of pores in the original non-worn surfaces, whereas the worn surfaces are subjected to a resultant of severe plastic deformation and scuffing when the polyester resin samples are thermally treated at 125°C.The dry-sliding wear and frictional behavior of a polymeric matrix material commonly used in fiber-reinforced composite applications are investigated as a function of thermal ageing temperature. More specifically, the commercially available polyester resin is used in this study to prepare disc-like samples of diameter 75mm and thickness 3mm, which are then aged isochronally at temperatures of 25°C, 75°C, 100°C and 125°C for a period of one hour. The wear test has been carried out against a high-speed carbon steel pin with a diameter of 5mm at a test load of 10N, in which the sliding distance is varied from 20m to 1450m with a sliding velocity of 0.4ms−1. The wear and frictional behavior of the polyester resin are found to be improved quite significantly when the samples are thermally treated at a temperature of around 125°C. At lower temperatures, softening of the polymeric sheet occurs due to minimum heat generation, which, in turn, results in a reduction of hardness and wear resistance. A surface invest...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"292 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":"115133084","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}
In this research, a non-Newtonian model for blood flow within a stenosed artery is investigated numerically. Finite Element Method of Galerkin’s weighted residual scheme is used to solve the transport equations with appropriate boundary conditions. The main objective of this study is to explore the influence of magnetic field on the blood flow. The numerical results are presented in terms of the velocity, pressure distribution and shear rate of the stenosed artery.In this research, a non-Newtonian model for blood flow within a stenosed artery is investigated numerically. Finite Element Method of Galerkin’s weighted residual scheme is used to solve the transport equations with appropriate boundary conditions. The main objective of this study is to explore the influence of magnetic field on the blood flow. The numerical results are presented in terms of the velocity, pressure distribution and shear rate of the stenosed artery.
{"title":"Numerical analysis of a blood flow model for arterial stenosis in presence of external magnetic field","authors":"A. Akter, S. Parvin","doi":"10.1063/1.5115932","DOIUrl":"https://doi.org/10.1063/1.5115932","url":null,"abstract":"In this research, a non-Newtonian model for blood flow within a stenosed artery is investigated numerically. Finite Element Method of Galerkin’s weighted residual scheme is used to solve the transport equations with appropriate boundary conditions. The main objective of this study is to explore the influence of magnetic field on the blood flow. The numerical results are presented in terms of the velocity, pressure distribution and shear rate of the stenosed artery.In this research, a non-Newtonian model for blood flow within a stenosed artery is investigated numerically. Finite Element Method of Galerkin’s weighted residual scheme is used to solve the transport equations with appropriate boundary conditions. The main objective of this study is to explore the influence of magnetic field on the blood flow. The numerical results are presented in terms of the velocity, pressure distribution and shear rate of the stenosed artery.","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"96 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":"122583067","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 precise understanding of the aerosol particle transport and deposition (TD) in the realistic mouth-throat model is important for the respiratory health risk assessment and effective delivery of the aerosol medicine to the targeted positions of the lung. A wide range of studies have developed the particle TD framework for both idealized and non-idealized extra-thoracic airways. However, all of the existing in silico and experimental model reports a significant amount of aerosol particles are deposit at the extra-thoracic airways and the existing drug delivery device can deliver only 12 percent of the aerosol drug to the targeted position of the lung. This study aims to increase the efficiency of the targeted drug delivery by developing a realistic particle transport model for CT-Scan based mouth-throat replica. A 3-D realistic mouth-throat model is developed from the CT-Scan DiCom images of a healthy adult cast. High-Quality computational cells are generated for the replica model and the proper grid refinement test has been performed. ANSYS Fluent (19.1) solver is used for the particle TD computation. Tecplot and MATLAB software are used for the post-processing purpose. The numerical results report that the breathing pattern and particle diameter influences the overall particle TD in the mouth-throat model. The numerical results also depict different deposition hot spots for the mouth-throat model, which will eventually help to design a better drug delivery device. The numerical results reported that only 13.67 percent of the 10-μm diameter particles are deposited at the mouth-throat model at 15 lpm flow rate and which indicate that the remaining particles will move to the beyond airways. The present results along with more case studies will develop the understanding of the realistic particle deposition in the extrathoracic airways.A precise understanding of the aerosol particle transport and deposition (TD) in the realistic mouth-throat model is important for the respiratory health risk assessment and effective delivery of the aerosol medicine to the targeted positions of the lung. A wide range of studies have developed the particle TD framework for both idealized and non-idealized extra-thoracic airways. However, all of the existing in silico and experimental model reports a significant amount of aerosol particles are deposit at the extra-thoracic airways and the existing drug delivery device can deliver only 12 percent of the aerosol drug to the targeted position of the lung. This study aims to increase the efficiency of the targeted drug delivery by developing a realistic particle transport model for CT-Scan based mouth-throat replica. A 3-D realistic mouth-throat model is developed from the CT-Scan DiCom images of a healthy adult cast. High-Quality computational cells are generated for the replica model and the proper grid refi...
{"title":"Aerosol particle transport and deposition in a CT-scan based mouth-throat model","authors":"S. Saha, M. Islam, M. Rahimi-Gorji, M. Molla","doi":"10.1063/1.5115882","DOIUrl":"https://doi.org/10.1063/1.5115882","url":null,"abstract":"A precise understanding of the aerosol particle transport and deposition (TD) in the realistic mouth-throat model is important for the respiratory health risk assessment and effective delivery of the aerosol medicine to the targeted positions of the lung. A wide range of studies have developed the particle TD framework for both idealized and non-idealized extra-thoracic airways. However, all of the existing in silico and experimental model reports a significant amount of aerosol particles are deposit at the extra-thoracic airways and the existing drug delivery device can deliver only 12 percent of the aerosol drug to the targeted position of the lung. This study aims to increase the efficiency of the targeted drug delivery by developing a realistic particle transport model for CT-Scan based mouth-throat replica. A 3-D realistic mouth-throat model is developed from the CT-Scan DiCom images of a healthy adult cast. High-Quality computational cells are generated for the replica model and the proper grid refinement test has been performed. ANSYS Fluent (19.1) solver is used for the particle TD computation. Tecplot and MATLAB software are used for the post-processing purpose. The numerical results report that the breathing pattern and particle diameter influences the overall particle TD in the mouth-throat model. The numerical results also depict different deposition hot spots for the mouth-throat model, which will eventually help to design a better drug delivery device. The numerical results reported that only 13.67 percent of the 10-μm diameter particles are deposited at the mouth-throat model at 15 lpm flow rate and which indicate that the remaining particles will move to the beyond airways. The present results along with more case studies will develop the understanding of the realistic particle deposition in the extrathoracic airways.A precise understanding of the aerosol particle transport and deposition (TD) in the realistic mouth-throat model is important for the respiratory health risk assessment and effective delivery of the aerosol medicine to the targeted positions of the lung. A wide range of studies have developed the particle TD framework for both idealized and non-idealized extra-thoracic airways. However, all of the existing in silico and experimental model reports a significant amount of aerosol particles are deposit at the extra-thoracic airways and the existing drug delivery device can deliver only 12 percent of the aerosol drug to the targeted position of the lung. This study aims to increase the efficiency of the targeted drug delivery by developing a realistic particle transport model for CT-Scan based mouth-throat replica. A 3-D realistic mouth-throat model is developed from the CT-Scan DiCom images of a healthy adult cast. High-Quality computational cells are generated for the replica model and the proper grid refi...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"80 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":"124603478","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 present study reports the science-based fire scene reconstruction of a fatal fire that occurred in a high-rise residential building in Dhaka in 2010, taking the lives of 7 inhabitants. Numerical methods have been applied to analyze the deadly event in order to demonstrate different smoke propagation and to compare them with the official investigation report on the actual incident. In this investigation, Computational Fluid Dynamics (CFD)-based fire dynamics simulator PyroSim is used for exploring the fire spread and smoke propagation. The results suggest that teak wood would not have been the only fuel source in this incident. It is proposed that burning of other fuel with higher CO yield such as turpentine oil or white spirit, in addition to the teak wood in the apartment where interior decoration and carpentry work was going on and where the fire was initiated, results in the required high level of CO to cause the asphyxiation of the trapped occupants. It is also to be mentioned that the victims of casualty were entrapped by the smoke within the main staircase due to a drop in the tenability which caused the fatality. By analyzing the effects of smoke temperature, visibility, CO concentration, the tenability limit for this residential building is measured. The use of engineering analysis and modelling of fire for fire forensic analysis is considered to be an important tool in fire investigation, this paper reports first such study in Bangladesh.The present study reports the science-based fire scene reconstruction of a fatal fire that occurred in a high-rise residential building in Dhaka in 2010, taking the lives of 7 inhabitants. Numerical methods have been applied to analyze the deadly event in order to demonstrate different smoke propagation and to compare them with the official investigation report on the actual incident. In this investigation, Computational Fluid Dynamics (CFD)-based fire dynamics simulator PyroSim is used for exploring the fire spread and smoke propagation. The results suggest that teak wood would not have been the only fuel source in this incident. It is proposed that burning of other fuel with higher CO yield such as turpentine oil or white spirit, in addition to the teak wood in the apartment where interior decoration and carpentry work was going on and where the fire was initiated, results in the required high level of CO to cause the asphyxiation of the trapped occupants. It is also to be mentioned that the victims of ...
{"title":"Forensic analysis of a fatal fire incident in a high-rise residential building in Bangladesh, 2010 using fire modelling","authors":"S. Mahmud, F. Haque, M. Rahman","doi":"10.1063/1.5115930","DOIUrl":"https://doi.org/10.1063/1.5115930","url":null,"abstract":"The present study reports the science-based fire scene reconstruction of a fatal fire that occurred in a high-rise residential building in Dhaka in 2010, taking the lives of 7 inhabitants. Numerical methods have been applied to analyze the deadly event in order to demonstrate different smoke propagation and to compare them with the official investigation report on the actual incident. In this investigation, Computational Fluid Dynamics (CFD)-based fire dynamics simulator PyroSim is used for exploring the fire spread and smoke propagation. The results suggest that teak wood would not have been the only fuel source in this incident. It is proposed that burning of other fuel with higher CO yield such as turpentine oil or white spirit, in addition to the teak wood in the apartment where interior decoration and carpentry work was going on and where the fire was initiated, results in the required high level of CO to cause the asphyxiation of the trapped occupants. It is also to be mentioned that the victims of casualty were entrapped by the smoke within the main staircase due to a drop in the tenability which caused the fatality. By analyzing the effects of smoke temperature, visibility, CO concentration, the tenability limit for this residential building is measured. The use of engineering analysis and modelling of fire for fire forensic analysis is considered to be an important tool in fire investigation, this paper reports first such study in Bangladesh.The present study reports the science-based fire scene reconstruction of a fatal fire that occurred in a high-rise residential building in Dhaka in 2010, taking the lives of 7 inhabitants. Numerical methods have been applied to analyze the deadly event in order to demonstrate different smoke propagation and to compare them with the official investigation report on the actual incident. In this investigation, Computational Fluid Dynamics (CFD)-based fire dynamics simulator PyroSim is used for exploring the fire spread and smoke propagation. The results suggest that teak wood would not have been the only fuel source in this incident. It is proposed that burning of other fuel with higher CO yield such as turpentine oil or white spirit, in addition to the teak wood in the apartment where interior decoration and carpentry work was going on and where the fire was initiated, results in the required high level of CO to cause the asphyxiation of the trapped occupants. It is also to be mentioned that the victims of ...","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"2012 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":"123822216","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}
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}
Shajedul Hoque Thakur, M. Islam, Abrar Ul Karim, S. Saha, M. Hasan
A numerical study of two-dimensional, laminar, steady mixed convection heat transfer in a Cu-water nanofluid filled lid-driven square cavity with an isothermally heated cylinder has been conducted. The wall of the cylinder is maintained at a constant high temperature, whereas the walls of the cavity (including the moving lid) are maintained at a constant low temperature. The isothermally heated cylinder is placed at the center of the cavity. The fluid flow in the cavity is driven by the combined effect of the buoyancy force due to temperature gradient and forced flow due to the top moving wall in the +x direction. The developed mathematical model is governed by the two-dimensional continuity, momentum and energy equations, which are solved by using Galerkin finite element method. The working fluid inside the cavity is Cu-water nanofluid, where water has been considered as the base fluid. The influence of the Reynolds number (1 ≤ Re ≤ 500) and the solid volume fraction of the Cu nanoparticle (0≤ ϕ ≤0.05) on fluid flow and heat transfer has been numerically investigated for the case of pure mixed convection heat transfer. Numerical results are presented in terms of the distribution of streamlines and isothermal contours, local as well as average Nusselt number variation on the cylinder surface for different parametric conditions. It is observed that enhancement of heat transfer occurs significantly as Reynolds number and solid volume fraction of nanoparticle change continuously. Thus, the dynamic condition of the moving lid and solid volume fraction of the nanoparticle can be used as parameters for enhancing the heat transfer characteristics and flow behavior in that cavity.
{"title":"Numerical study of laminar mixed convection in a Cu-water nanofluid filled lid-driven square cavity with an isothermally heated cylinder","authors":"Shajedul Hoque Thakur, M. Islam, Abrar Ul Karim, S. Saha, M. Hasan","doi":"10.1063/1.5115924","DOIUrl":"https://doi.org/10.1063/1.5115924","url":null,"abstract":"A numerical study of two-dimensional, laminar, steady mixed convection heat transfer in a Cu-water nanofluid filled lid-driven square cavity with an isothermally heated cylinder has been conducted. The wall of the cylinder is maintained at a constant high temperature, whereas the walls of the cavity (including the moving lid) are maintained at a constant low temperature. The isothermally heated cylinder is placed at the center of the cavity. The fluid flow in the cavity is driven by the combined effect of the buoyancy force due to temperature gradient and forced flow due to the top moving wall in the +x direction. The developed mathematical model is governed by the two-dimensional continuity, momentum and energy equations, which are solved by using Galerkin finite element method. The working fluid inside the cavity is Cu-water nanofluid, where water has been considered as the base fluid. The influence of the Reynolds number (1 ≤ Re ≤ 500) and the solid volume fraction of the Cu nanoparticle (0≤ ϕ ≤0.05) on fluid flow and heat transfer has been numerically investigated for the case of pure mixed convection heat transfer. Numerical results are presented in terms of the distribution of streamlines and isothermal contours, local as well as average Nusselt number variation on the cylinder surface for different parametric conditions. It is observed that enhancement of heat transfer occurs significantly as Reynolds number and solid volume fraction of nanoparticle change continuously. Thus, the dynamic condition of the moving lid and solid volume fraction of the nanoparticle can be used as parameters for enhancing the heat transfer characteristics and flow behavior in that cavity.","PeriodicalId":423885,"journal":{"name":"8TH BSME INTERNATIONAL CONFERENCE ON THERMAL ENGINEERING","volume":"8 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":"127978859","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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