Pub Date : 2022-06-29DOI: 10.3329/jname.v19i1.52171
Rajasekar Rajendran, Vadivuchezhian Kaliveeran
This paper proposes a new thin curved sensor/strip to measure the relative slip between pad and specimen under fretting condition. Since the relative contact displacement is an important parameter to categorize the fretting process, the measurement of contact displacement between pad and specimen is necessary. Because of high yield strength and the ability to return to its initial position even with notable deflection, the spring steel have chosen to fabricate the thin curved strip. Before the fabrication, the detailed Finite Element Analysis (FEA) of the thin curved sensor was carried out. The strip consists of different shapes (rectangular, circular and elliptical) of slots and the number of slots in each strip is varied from 2 to 6. The Strain Energy Approach (SEA) has been used to calculate the displacement for the curved strip and it was compared, verified and validated with its FEA and Experimental results. From FEA study of thin curved strip with slots, four configurations were chosen to measure micro level displacement between pad and specimen under fretting experiments. The study reveals that the increasing number and size of holes presented in the curved strip indicate that the increased in displacement and von-Mises stress values which offers the higher flexibility to the strip. The reduction in area and minimum thickness of the curved strip could be the reason for the decrease in the stiffness of the curved strip. This study explores the use of new simple and novel instrument/sensor to capture the micro level relative displacement between the pad and specimen under fretting condition.
{"title":"Design of thin curved sensor to measure contact slip in fretting experiments","authors":"Rajasekar Rajendran, Vadivuchezhian Kaliveeran","doi":"10.3329/jname.v19i1.52171","DOIUrl":"https://doi.org/10.3329/jname.v19i1.52171","url":null,"abstract":"This paper proposes a new thin curved sensor/strip to measure the relative slip between pad and specimen under fretting condition. Since the relative contact displacement is an important parameter to categorize the fretting process, the measurement of contact displacement between pad and specimen is necessary. Because of high yield strength and the ability to return to its initial position even with notable deflection, the spring steel have chosen to fabricate the thin curved strip. Before the fabrication, the detailed Finite Element Analysis (FEA) of the thin curved sensor was carried out. The strip consists of different shapes (rectangular, circular and elliptical) of slots and the number of slots in each strip is varied from 2 to 6. The Strain Energy Approach (SEA) has been used to calculate the displacement for the curved strip and it was compared, verified and validated with its FEA and Experimental results. From FEA study of thin curved strip with slots, four configurations were chosen to measure micro level displacement between pad and specimen under fretting experiments. The study reveals that the increasing number and size of holes presented in the curved strip indicate that the increased in displacement and von-Mises stress values which offers the higher flexibility to the strip. The reduction in area and minimum thickness of the curved strip could be the reason for the decrease in the stiffness of the curved strip. This study explores the use of new simple and novel instrument/sensor to capture the micro level relative displacement between the pad and specimen under fretting condition.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42748416","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}
Pub Date : 2022-06-29DOI: 10.3329/jname.v19i1.55052
M. M. Channakote, V. D. Kalse
Abstract: This paper investigates the peristaltic transport of Ellis fluid in a non-uniform tube with combined/individual effects of convective and viscous dissipation analytically. Low Reynolds number and long-wavelength approximation assumptions are considered in the analysis. An examination of the properties of the walls is also carried out. The expressions for velocity, temperature profile, and stream function are obtained subjected to convective boundary conditions. The peristaltic transport's significant characteristics are delineated with plots for various Ellis fluid parameter values. The viscous dissipation effects are found to be related to the Brinkman number, so it leads to rising fluid temperature in all cases.
{"title":"Combined convective and viscous dissipation effects on peristaltic flow of Ellis fluid in non uniform tube","authors":"M. M. Channakote, V. D. Kalse","doi":"10.3329/jname.v19i1.55052","DOIUrl":"https://doi.org/10.3329/jname.v19i1.55052","url":null,"abstract":"Abstract: \u0000This paper investigates the peristaltic transport of Ellis fluid in a non-uniform tube with combined/individual effects of convective and viscous dissipation analytically. Low Reynolds number and long-wavelength approximation assumptions are considered in the analysis. An examination of the properties of the walls is also carried out. The expressions for velocity, temperature profile, and stream function are obtained subjected to convective boundary conditions. The peristaltic transport's significant characteristics are delineated with plots for various Ellis fluid parameter values. The viscous dissipation effects are found to be related to the Brinkman number, so it leads to rising fluid temperature in all cases.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49561453","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}
Pub Date : 2022-06-29DOI: 10.3329/jname.v19i1.53078
K. I. B. Iqbal, A. Rafique, M. F. Uddin
Inventory models for deteriorating items of a supply chain is of critical essence to the maritime industry. This study proposes a real and economically efficient multicriteria inventory policy of inventory models for deteriorating items of a supply chain with nonlinear ramp functions and permissible delay in payment under inflation, two conditions Shortages Followed by Inventory (SFI) and Inventory Followed by Shortages (IFS) have been considered for the formulation of models. Both the models consist of ordering cost, unit cost, deterioration cost, shortage cost and holding cost with replenishment where delay in payments is allowed. The development of these models is to minimize the total average cost per unit time. In order to validate the models, numerical examples have been considered and the sensitivity of several major parameters of exponential and quadratic functions is analyzed. From the numerical result, it is clear that the cost per unit time of IFS model decreases with the increment of the values of parameters of the quadratic function and holding cost whereas, with the increment of the values of parameters of the exponential function as well as holding cost per unite time, the cost per unit time of SFI model decreases. However, if the values of the parameters of the exponential functions as well as ordering cost and shortage cost increase, the cost per unit time of IFS model increases. On the other hand, it will also increase considering SFI condition, if the values of parameters of the quadratic function as well as ordering cost and shortage cost increase. Finally, it is observed that the model considering IFS case works better than SFI model up to a certain level.
{"title":"Inventory optimization model of deteriorating items with nonlinear ramped type demand function","authors":"K. I. B. Iqbal, A. Rafique, M. F. Uddin","doi":"10.3329/jname.v19i1.53078","DOIUrl":"https://doi.org/10.3329/jname.v19i1.53078","url":null,"abstract":"Inventory models for deteriorating items of a supply chain is of critical essence to the maritime industry. This study proposes a real and economically efficient multicriteria inventory policy of inventory models for deteriorating items of a supply chain with nonlinear ramp functions and permissible delay in payment under inflation, two conditions Shortages Followed by Inventory (SFI) and Inventory Followed by Shortages (IFS) have been considered for the formulation of models. Both the models consist of ordering cost, unit cost, deterioration cost, shortage cost and holding cost with replenishment where delay in payments is allowed. The development of these models is to minimize the total average cost per unit time. In order to validate the models, numerical examples have been considered and the sensitivity of several major parameters of exponential and quadratic functions is analyzed. From the numerical result, it is clear that the cost per unit time of IFS model decreases with the increment of the values of parameters of the quadratic function and holding cost whereas, with the increment of the values of parameters of the exponential function as well as holding cost per unite time, the cost per unit time of SFI model decreases. However, if the values of the parameters of the exponential functions as well as ordering cost and shortage cost increase, the cost per unit time of IFS model increases. On the other hand, it will also increase considering SFI condition, if the values of parameters of the quadratic function as well as ordering cost and shortage cost increase. Finally, it is observed that the model considering IFS case works better than SFI model up to a certain level. \u0000 ","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48965448","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}
Pub Date : 2022-06-29DOI: 10.3329/jname.v19i1.55029
R. Parthiban, G. Palani
The current study aims to explore stagnation spot flow of a micropolar liquid about a plain linear exponentially expanding penetrable surface in the incidence of chemical reaction and in-house heat production/absorption. Through similarity mapping, the mathematical modeling statements are reformed as ODE's and numerical results are found by shooting techniques. The impact of varying physical constants on momentum, micro-rotation, temperature and concentration are demonstrated through graphs. The computed measures including shear, couple stress and mass transfer with distinct measures of factors involved in this proposed problem are presented through a table. The presence of heat source increases the temperature of the fluid but has no impact on the velocity, angular velocity and concentration.
{"title":"Similarity solution of stagnation – spot flow of a micropolar fluid above a flat exponentially elongating penetrable surface with concentration and heat production/absorption","authors":"R. Parthiban, G. Palani","doi":"10.3329/jname.v19i1.55029","DOIUrl":"https://doi.org/10.3329/jname.v19i1.55029","url":null,"abstract":"The current study aims to explore stagnation spot flow of a micropolar liquid about a plain linear exponentially expanding penetrable surface in the incidence of chemical reaction and in-house heat production/absorption. Through similarity mapping, the mathematical modeling statements are reformed as ODE's and numerical results are found by shooting techniques. The impact of varying physical constants on momentum, micro-rotation, temperature and concentration are demonstrated through graphs. The computed measures including shear, couple stress and mass transfer with distinct measures of factors involved in this proposed problem are presented through a table. The presence of heat source increases the temperature of the fluid but has no impact on the velocity, angular velocity and concentration.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47944860","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}
Pub Date : 2021-12-31DOI: 10.3329/jname.v18i2.51412
T. G. Tran, V. T. Doan
In shipbuilding, the process of forming flat metal plate into curved hull plates with compound shapes is very important and has greatly affected many economic and technical factors such as strength, quality, and aesthetics of the hull, construction cost and time, etc. Currently, the forming method of curved hull plates by line heating is used effectively and commonly in many shipyards, however, its main problem is very difficult to determine where and how much to heat on the flat metal plate to obtain the plate of a certain shape. In this article, a finite element model is established and adjusted based on the actual data to numerical simulate the process of forming hull plates by using flame torch line heating. Base on this, the suitable position and temperature for the heating lines in the forming process are determined to form a metal plate into hull plates with the exact desired shapes. This research has been applied for forming by torch line heating of two plates, denoted K1 and K10, in the bulb bow of a 20,000 DWT cargo ship, built at Camranh Shipyard in Vietnam with the deformation deviations between the actual and desired plate surfaces are within ± 3%.
{"title":"A new approach to determining heating parameters suitable for hull plate forming by torch line heating","authors":"T. G. Tran, V. T. Doan","doi":"10.3329/jname.v18i2.51412","DOIUrl":"https://doi.org/10.3329/jname.v18i2.51412","url":null,"abstract":"In shipbuilding, the process of forming flat metal plate into curved hull plates with compound shapes is very important and has greatly affected many economic and technical factors such as strength, quality, and aesthetics of the hull, construction cost and time, etc. Currently, the forming method of curved hull plates by line heating is used effectively and commonly in many shipyards, however, its main problem is very difficult to determine where and how much to heat on the flat metal plate to obtain the plate of a certain shape. In this article, a finite element model is established and adjusted based on the actual data to numerical simulate the process of forming hull plates by using flame torch line heating. Base on this, the suitable position and temperature for the heating lines in the forming process are determined to form a metal plate into hull plates with the exact desired shapes. This research has been applied for forming by torch line heating of two plates, denoted K1 and K10, in the bulb bow of a 20,000 DWT cargo ship, built at Camranh Shipyard in Vietnam with the deformation deviations between the actual and desired plate surfaces are within ± 3%. ","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46202320","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}
Pub Date : 2021-12-31DOI: 10.3329/jname.v18i2.53624
Md Nasir Uddin, M. A. Alim, M. Karim, Md. Monjarul Alam
Blood flow in a double aneurysmatic artery of the normal tissue is studied. A Finite Element method is used to analyze numerical simulation of blood flow through aneurysmatic arteries. The Newtonian, generalized Newtonian, Oldroyd-B and generalized Oldroyd-B models are considered due to the behavior of blood viscosity. In this paper, the effect of aneurysmatic artery on blood flow with permeability in human organ has been investigated. The non-Newtonian models have been applied to study the blood velocity, pressure, and wall shear stress in an aneurysmatic artery. A set of partial differential equations are transformed into dimensionless equations using non-dimensional variables and solved numerically. We have focused our consideration on the simulation of blood velocity and pressure in terms of blood flow rate for various Weissenberg numbers (Wi) and Peclet numbers (Pe). The important effects on blood flow of aneursymatic artery for blood velocity, pressure and wall stress profiles are presented graphically for Newtonian and non-Newtonian models.
{"title":"Effect of aneurysmatic artery on blood flow having permeability in human organ","authors":"Md Nasir Uddin, M. A. Alim, M. Karim, Md. Monjarul Alam","doi":"10.3329/jname.v18i2.53624","DOIUrl":"https://doi.org/10.3329/jname.v18i2.53624","url":null,"abstract":" Blood flow in a double aneurysmatic artery of the normal tissue is studied. A Finite Element method is used to analyze numerical simulation of blood flow through aneurysmatic arteries. The Newtonian, generalized Newtonian, Oldroyd-B and generalized Oldroyd-B models are considered due to the behavior of blood viscosity. In this paper, the effect of aneurysmatic artery on blood flow with permeability in human organ has been investigated. The non-Newtonian models have been applied to study the blood velocity, pressure, and wall shear stress in an aneurysmatic artery. A set of partial differential equations are transformed into dimensionless equations using non-dimensional variables and solved numerically. We have focused our consideration on the simulation of blood velocity and pressure in terms of blood flow rate for various Weissenberg numbers (Wi) and Peclet numbers (Pe). The important effects on blood flow of aneursymatic artery for blood velocity, pressure and wall stress profiles are presented graphically for Newtonian and non-Newtonian models. ","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46748937","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}
Pub Date : 2021-12-31DOI: 10.3329/jname.v18i2.45982
K. Varghese, Vinay Gopi Nair, Avinashm Godey, P. Kumar
The Circulation Water Channel (CWC) is an experimental facility available at Indian Maritime University, Visakhapatnam Campus. A study for comparing the flow pattern and velocity in the test section, for different configurations of the CWC, is complex. To study the flow, a physical model of the CWC, with different configurations, should be made, which in overall is a complicated and time-consuming exercise. But this difficulty can be overcome through using Computational Fluid Dynamics (CFD) analysis, as in this study, where a CFD analysis is done using ‘STAR-CCM+’ software. A CFD model of the existing CWC [corresponding to the 1:4 scale setup at IMUV], is first made, and its validity is checked, by comparing the results of the CFD analysis, against those results obtained from the experimental analysis. On successfully validating the results, modifications are suggested for rectifying the disturbance which is present in the test section. The test section is the area in the CWC where experimental activities are carried out. In order to carry out the experiments with a certain degree of accuracy, it is important to have a smooth streamlined flow in the test section. To ensure this, a honeycomb structure is positioned such that the flow enters the test section through the honeycomb, which streamlines the flow. On successfully rectifying the disturbance, studies are carried out to improve the streamlined flow in the test section, for which, different configurations of honeycomb structure are studied. The optimum honeycomb structure, which produces a smooth flow in the test section of a CWC is found out, by conducting analyses for different shapes - i.e. for shapes ranging from rectangular to hexagonal and circular, against different inlet velocities. The present paper sums up the findings of our earlier research, ‘CFD as a Tool to Validate and Modify the Flow in the Test Section of a Circulating Water Channel’, and ‘Study of Flow in the Test Section of a Circulating Water Channel by Varying the Honey Comb Cross Section’, which were published in the conference proceedings of Indian Institute of Technology, Madras, and Indian Maritime University, Visakhapatnam, respectively.
{"title":"A study for validating, rectifying and optimizing the flow in the test section of a circulating water channel","authors":"K. Varghese, Vinay Gopi Nair, Avinashm Godey, P. Kumar","doi":"10.3329/jname.v18i2.45982","DOIUrl":"https://doi.org/10.3329/jname.v18i2.45982","url":null,"abstract":"The Circulation Water Channel (CWC) is an experimental facility available at Indian Maritime University, Visakhapatnam Campus. A study for comparing the flow pattern and velocity in the test section, for different configurations of the CWC, is complex. To study the flow, a physical model of the CWC, with different configurations, should be made, which in overall is a complicated and time-consuming exercise. But this difficulty can be overcome through using Computational Fluid Dynamics (CFD) analysis, as in this study, where a CFD analysis is done using ‘STAR-CCM+’ software. A CFD model of the existing CWC [corresponding to the 1:4 scale setup at IMUV], is first made, and its validity is checked, by comparing the results of the CFD analysis, against those results obtained from the experimental analysis. \u0000On successfully validating the results, modifications are suggested for rectifying the disturbance which is present in the test section. The test section is the area in the CWC where experimental activities are carried out. In order to carry out the experiments with a certain degree of accuracy, it is important to have a smooth streamlined flow in the test section. To ensure this, a honeycomb structure is positioned such that the flow enters the test section through the honeycomb, which streamlines the flow. \u0000On successfully rectifying the disturbance, studies are carried out to improve the streamlined flow in the test section, for which, different configurations of honeycomb structure are studied. The optimum honeycomb structure, which produces a smooth flow in the test section of a CWC is found out, by conducting analyses for different shapes - i.e. for shapes ranging from rectangular to hexagonal and circular, against different inlet velocities. \u0000The present paper sums up the findings of our earlier research, ‘CFD as a Tool to Validate and Modify the Flow in the Test Section of a Circulating Water Channel’, and ‘Study of Flow in the Test Section of a Circulating Water Channel by Varying the Honey Comb Cross Section’, which were published in the conference proceedings of Indian Institute of Technology, Madras, and Indian Maritime University, Visakhapatnam, respectively.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41449028","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}
Pub Date : 2021-12-31DOI: 10.3329/jname.v18i2.38099
Agung Purwana, I. Ariana, W. Wardhana
In this study, numerical simulations on the noise of the underwater marine propeller for different pressures, skew angles, and performance conditions are investigated. The study has been carried out for the prediction of cavity and noise cavitation characteristics of the propeller. The blade sheet cavitation created by an underwater propeller is then evaluated using numerical analysis. The cavitation and cavity around marine propellers were predicted using MRF (Multiple Reference Frame) techniques. The simulation uses the Reynolds Averaged Navier-Stokes (RANS) formulation with the turbulence model k-ω Shear Stress Transport and the Fast Fourier Transform. The FW-H equation is used to measure far-field radiation under various operating conditions. The simulation is carried out to present that the pressure and skew propeller angles have an effect on the form and area of the cavity, as well as cavitation noise. The noise characteristics at various positions of hydrophones and speeds of the marine propeller are presented. The 3D model of B-series marine propeller with D=250 mm, Z=4, P/D= 1.0, AE/AO=0.55, skew angles of 16, 35, 53, and 72 degrees at advance coefficient, J=0.221, is used for the simulation
{"title":"Numerical study on the cavitation noise of marine skew propellers","authors":"Agung Purwana, I. Ariana, W. Wardhana","doi":"10.3329/jname.v18i2.38099","DOIUrl":"https://doi.org/10.3329/jname.v18i2.38099","url":null,"abstract":"In this study, numerical simulations on the noise of the underwater marine propeller for different pressures, skew angles, and performance conditions are investigated. The study has been carried out for the prediction of cavity and noise cavitation characteristics of the propeller. The blade sheet cavitation created by an underwater propeller is then evaluated using numerical analysis. The cavitation and cavity around marine propellers were predicted using MRF (Multiple Reference Frame) techniques. The simulation uses the Reynolds Averaged Navier-Stokes (RANS) formulation with the turbulence model k-ω Shear Stress Transport and the Fast Fourier Transform. The FW-H equation is used to measure far-field radiation under various operating conditions. The simulation is carried out to present that the pressure and skew propeller angles have an effect on the form and area of the cavity, as well as cavitation noise. The noise characteristics at various positions of hydrophones and speeds of the marine propeller are presented. The 3D model of B-series marine propeller with D=250 mm, Z=4, P/D= 1.0, AE/AO=0.55, skew angles of 16, 35, 53, and 72 degrees at advance coefficient, J=0.221, is used for the simulation","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46377009","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}
Pub Date : 2021-12-31DOI: 10.3329/jname.v18i2.51972
R. K. Chanda, M. Hasan, M. Alam, R. Mondal
Investigation on fluid flow and energy distribution in a rotating coiled rectangular duct (CRD) with differentially heated horizontal walls has been analyzed numerically by using a spectral-based numerical scheme. The system is rotated around the vertical axis in the clockwise direction over the Taylor number (Tr) ranging from 0 to 2000 keeping the other parameters constant as aspect ratio Ar =3, curvature ratio BETA=0.5 the Dean number Dn = 1000 and the Prandtl number Pr = 7.0 (water). To reveal steady solution (SS) curves, we applied path continuation technique and obtained five asymmetric SS curves comprising with 2- to 8-pair cell. A bar diagram is also drawn to visualize, at a glance, longitudinal vortex generation on various curves of steady solutions. To explore unsteady behavior, time-progression analysis is performed and flow characteristics are precisely determined by obtaining phase space trajectory of the solutions. The transient flow demonstrates various stages of physically realizable solutions including chaotic, multi-periodic, periodic and steady-state; and it is found that the number of secondary vortices declines as Tr is increased. Convective heat transfer (CHT) is computed and the corresponding dependence on the flow stages is discussed accurately. Finally, a comparison has been made between the numerical computation and experimental investigations which shows a benchmark agreement.
{"title":"A computational study on flow characteristics and energy distribution in a rotating coiled rectangular duct with longitudinal vortex generation","authors":"R. K. Chanda, M. Hasan, M. Alam, R. Mondal","doi":"10.3329/jname.v18i2.51972","DOIUrl":"https://doi.org/10.3329/jname.v18i2.51972","url":null,"abstract":"Investigation on fluid flow and energy distribution in a rotating coiled rectangular duct (CRD) with differentially heated horizontal walls has been analyzed numerically by using a spectral-based numerical scheme. The system is rotated around the vertical axis in the clockwise direction over the Taylor number (Tr) ranging from 0 to 2000 keeping the other parameters constant as aspect ratio Ar =3, curvature ratio BETA=0.5 the Dean number Dn = 1000 and the Prandtl number Pr = 7.0 (water). To reveal steady solution (SS) curves, we applied path continuation technique and obtained five asymmetric SS curves comprising with 2- to 8-pair cell. A bar diagram is also drawn to visualize, at a glance, longitudinal vortex generation on various curves of steady solutions. To explore unsteady behavior, time-progression analysis is performed and flow characteristics are precisely determined by obtaining phase space trajectory of the solutions. The transient flow demonstrates various stages of physically realizable solutions including chaotic, multi-periodic, periodic and steady-state; and it is found that the number of secondary vortices declines as Tr is increased. Convective heat transfer (CHT) is computed and the corresponding dependence on the flow stages is discussed accurately. Finally, a comparison has been made between the numerical computation and experimental investigations which shows a benchmark agreement. ","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46764329","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}
Pub Date : 2021-12-31DOI: 10.3329/jname.v18i2.52134
K. Viswanathan, Manu, Subba Rao
In this paper, hydrodynamic characteristics of caisson type breakwater are investigated through physical model approach and a numerical model based on the Volume of Fluid (VOF) is validated. The investigations are carried out for varying wave characteristics and depth of water 0.50 m. In an experimental study, to understand the model and scale effects for the desired wave conditions is a critical task in all-time conditions. So, it is also necessary to develop an appropriate numerical model to understand the hydrodynamics of the selected test model. Using the Volume of Fluid (VOF) method and incompressible open channel fluid flow a 2D numerical wave flume is developed using ANSYS- Fluent platform. The wave boundary conditions are adopted by solving the Reynolds-Averaged Navier Stokes equations (RANS equation) and especially with k—ε model to examine the effects of turbulence on the numerical results. The wave forces, wave runup, and wave reflection characteristics on the test model are measured for different wave characteristics, and results obtained from the numerical investigations are comparable with the experimental results to evident the relevance of the developed numerical model.
{"title":"Hydrodynamic performances of a wall type breakwater - a physical and numerical approach","authors":"K. Viswanathan, Manu, Subba Rao","doi":"10.3329/jname.v18i2.52134","DOIUrl":"https://doi.org/10.3329/jname.v18i2.52134","url":null,"abstract":"In this paper, hydrodynamic characteristics of caisson type breakwater are investigated through physical model approach and a numerical model based on the Volume of Fluid (VOF) is validated. The investigations are carried out for varying wave characteristics and depth of water 0.50 m. In an experimental study, to understand the model and scale effects for the desired wave conditions is a critical task in all-time conditions. So, it is also necessary to develop an appropriate numerical model to understand the hydrodynamics of the selected test model. Using the Volume of Fluid (VOF) method and incompressible open channel fluid flow a 2D numerical wave flume is developed using ANSYS- Fluent platform. The wave boundary conditions are adopted by solving the Reynolds-Averaged Navier Stokes equations (RANS equation) and especially with k—ε model to examine the effects of turbulence on the numerical results. The wave forces, wave runup, and wave reflection characteristics on the test model are measured for different wave characteristics, and results obtained from the numerical investigations are comparable with the experimental results to evident the relevance of the developed numerical model.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45485851","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：