Pub Date : 2016-06-15DOI: 10.3329/JNAME.V13I1.25338
P. Krishna, N. Sandeep, J. V. R. Reddy, V. Sugunamma
This paper deals with the heat and mass transfer in unsteady flow of Powell-Eyring fluid past an inclined stretching sheet in the presence of radiation, non-uniform heat source/sink and chemical reaction with suction/injection effects. The governing equations are reduced into system of ordinary differential equations using similarity transformation and solved numerically using Runge-Kutta based shooting technique. Results display the influence of governing parameters on the flow, heat and mass transfer, friction factor, local Nusselt and Sherwood numbers. Comparisons are made with the existed studies. Present results have an excellent agreement with the existed studies. Results indicate that an increase in the chemical reaction parameter depreciates the friction factor, heat transfer rate and enhances the mass transfer rate. Dual solutions exist only for certain range of suction/injection parameters.
{"title":"DUAL SOLUTIONS FOR UNSTEADY FLOW OF POWELL-EYRING FLUID PAST AN INCLINED STRETCHING SHEET","authors":"P. Krishna, N. Sandeep, J. V. R. Reddy, V. Sugunamma","doi":"10.3329/JNAME.V13I1.25338","DOIUrl":"https://doi.org/10.3329/JNAME.V13I1.25338","url":null,"abstract":"This paper deals with the heat and mass transfer in unsteady flow of Powell-Eyring fluid past an inclined stretching sheet in the presence of radiation, non-uniform heat source/sink and chemical reaction with suction/injection effects. The governing equations are reduced into system of ordinary differential equations using similarity transformation and solved numerically using Runge-Kutta based shooting technique. Results display the influence of governing parameters on the flow, heat and mass transfer, friction factor, local Nusselt and Sherwood numbers. Comparisons are made with the existed studies. Present results have an excellent agreement with the existed studies. Results indicate that an increase in the chemical reaction parameter depreciates the friction factor, heat transfer rate and enhances the mass transfer rate. Dual solutions exist only for certain range of suction/injection parameters.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2016-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V13I1.25338","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69515413","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 : 2015-12-30DOI: 10.3329/JNAME.V12I2.24665
H. S. Hedia, S. Aldousari, A. Abdellatif, G. S. A. Hafeez
In the present paper, the stiffening effect of carbon nanotubes is quantitatively investigated by micromechanics methods. The Mori-Tanaka effective-field method is employed to calculate the effective elastic moduli of composites with aligned or randomly oriented straight nanotubes. In addition, the epoxy resin is modified experimentally by adding SWCNT with different ratio i.e 0, 0.1, 0.3, 0.5 and 0.7 wt.-% . A comparison between the results for SWCNT/epoxy nanocomposite which obtained analytically and experimentally is done. In the experimental work the epoxy resin is modified by adding SWCNT with different ratio i.e 0, 0.1, 0.3, 0.5 and 0.7 wt.-% . The materials are characterized in tension to obtain the mechanical properties of SWCNT/epoxy nanocomposite experimentally. The results of micromechanics methods indicated that the CNTs are highly anisotropic, with Young’s modulus in the tube direction two orders of magnitude higher than that normal to the tube. The results shows a nanotube volume fraction of 0.3%of SWCNT improve all mechanical properties such as the tensile strength, modulus of elasticity and the toughness. Avoid the volume fraction greater than 0.5% SWCNT. The optimal value achieved experimentally, (at 0.3% SWCNT) lies between the analytical values (that achieved parallel to the CNT and the randomly orientated straight CNTs ) .
{"title":"INVESTIGATION OF THE MECHANICAL PROPERTIES OF NANOCOMPOSITE SWCNTS/EPOXY BY MICROMECHANICS METHODS AND EXPERIMENTAL WORKS","authors":"H. S. Hedia, S. Aldousari, A. Abdellatif, G. S. A. Hafeez","doi":"10.3329/JNAME.V12I2.24665","DOIUrl":"https://doi.org/10.3329/JNAME.V12I2.24665","url":null,"abstract":"In the present paper, the stiffening effect of carbon nanotubes is quantitatively investigated by micromechanics methods. The Mori-Tanaka effective-field method is employed to calculate the effective elastic moduli of composites with aligned or randomly oriented straight nanotubes. In addition, the epoxy resin is modified experimentally by adding SWCNT with different ratio i.e 0, 0.1, 0.3, 0.5 and 0.7 wt.-% . A comparison between the results for SWCNT/epoxy nanocomposite which obtained analytically and experimentally is done. In the experimental work the epoxy resin is modified by adding SWCNT with different ratio i.e 0, 0.1, 0.3, 0.5 and 0.7 wt.-% . The materials are characterized in tension to obtain the mechanical properties of SWCNT/epoxy nanocomposite experimentally. The results of micromechanics methods indicated that the CNTs are highly anisotropic, with Young’s modulus in the tube direction two orders of magnitude higher than that normal to the tube. The results shows a nanotube volume fraction of 0.3%of SWCNT improve all mechanical properties such as the tensile strength, modulus of elasticity and the toughness. Avoid the volume fraction greater than 0.5% SWCNT. The optimal value achieved experimentally, (at 0.3% SWCNT) lies between the analytical values (that achieved parallel to the CNT and the randomly orientated straight CNTs ) .","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I2.24665","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69515023","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 : 2015-12-30DOI: 10.3329/JNAME.V12I2.19549
Y. Yanuar, G. Gunawan, M. A. Talahatu, R. T. Indrawati, A. Jamaluddin
Resistance reduction in ship becomes an important issue to be investigated. Energy consumption and its efficiency are related toward drag reduction. Drag reduction in fluid flow can be obtained by providing polymer additives, coating, surfactants, fiber and special roughness on the surface hull. Fish skin surface coated with biopolymers viscous fluid (slime) is one method in frictional resistance reduction. The aim of this is to understanding the effect of drag reduction using eel slime biopolymer in unsymmetrical trimaran ship model. The Investigation was conducted using towing tank test with variation of velocity. The dimension of trimaran model are L = 2 m, B = 0.20 m and T = 0.065 m. The ship model resistance was precisely measured by a load cell transducer. The comparison of resistance on trimaran ship model coated and uncoated by eel slime are shown on the graph as a function of the total drag coefficient and Froude number. It is discovered the trimaran ship model by eel slime has higher drag reduction compared to trimaran with no eel slime at similar displacement. The result shows the drag reduction about 11 % at Fr 0.35.
船舶减阻成为研究的重要课题。能源消耗及其效率与减阻有关。通过在船体表面提供聚合物添加剂、涂层、表面活性剂、纤维和特殊粗糙度，可以减少流体流动的阻力。鱼皮表面涂覆生物聚合物黏液(黏液)是降低鱼皮摩擦阻力的一种方法。目的是了解在非对称三体船模型中使用鳗鱼黏液生物聚合物的减阻效果。采用随速度变化的拖曳槽试验进行了研究。三体船模型的尺寸为L = 2 m, B = 0.20 m, T = 0.065 m。用称重传感器精确测量了船模的电阻。图中给出了涂覆和未涂覆鳗鱼泥的三体船模型阻力随总阻力系数和弗劳德数的函数关系。研究发现，在相同排水量下，添加鳗鱼泥的三体船模型比未添加鳗鱼泥的三体船模型具有更高的减阻性能。结果表明，在Fr为0.35时，阻力降低约11%。
{"title":"Resistance reduction on trimaran ship model by biopolymer of eel slime","authors":"Y. Yanuar, G. Gunawan, M. A. Talahatu, R. T. Indrawati, A. Jamaluddin","doi":"10.3329/JNAME.V12I2.19549","DOIUrl":"https://doi.org/10.3329/JNAME.V12I2.19549","url":null,"abstract":"Resistance reduction in ship becomes an important issue to be investigated. Energy consumption and its efficiency are related toward drag reduction. Drag reduction in fluid flow can be obtained by providing polymer additives, coating, surfactants, fiber and special roughness on the surface hull. Fish skin surface coated with biopolymers viscous fluid (slime) is one method in frictional resistance reduction. The aim of this is to understanding the effect of drag reduction using eel slime biopolymer in unsymmetrical trimaran ship model. The Investigation was conducted using towing tank test with variation of velocity. The dimension of trimaran model are L = 2 m, B = 0.20 m and T = 0.065 m. The ship model resistance was precisely measured by a load cell transducer. The comparison of resistance on trimaran ship model coated and uncoated by eel slime are shown on the graph as a function of the total drag coefficient and Froude number. It is discovered the trimaran ship model by eel slime has higher drag reduction compared to trimaran with no eel slime at similar displacement. The result shows the drag reduction about 11 % at Fr 0.35.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I2.19549","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514634","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 : 2015-12-30DOI: 10.3329/JNAME.V12I2.22351
P. Ghadimi, S. Tavakoli, M. A. F. Chekab, A. Dashtimanesh
Mathematical modeling of planing hulls and determination of their characteristics are the most important subjects in hydrodynamic study of planing vessels. In this paper, a new mathematical model has been developed based on pressure distribution. This model has been provided for two different situations: (1) for a situation in which all forces pass through the center of gravity and (2) for a situation in which forces don not necessarily pass through the center of gravity. Two algorithms have been designed for the governing equations. Computational results have been presented in the form of trim angle, total pressure, hydrodynamic and hydrostatic lift coefficients, spray apex and total resistance which includes frictional, spray and induced resistances. Accuracy of the model has been verified by comparing the numerical findings against the results of Savitsky's method and available experimental data. Good accuracy is displayed. Furthermore, effects of deadrise angle on trim angle of the craft, position of spray apex and resistance have been investigated.
{"title":"Introducing a particular mathematical model for predicting the resistance and performance of prismatic planing hulls in calm water by means of total pressure distribution","authors":"P. Ghadimi, S. Tavakoli, M. A. F. Chekab, A. Dashtimanesh","doi":"10.3329/JNAME.V12I2.22351","DOIUrl":"https://doi.org/10.3329/JNAME.V12I2.22351","url":null,"abstract":"Mathematical modeling of planing hulls and determination of their characteristics are the most important subjects in hydrodynamic study of planing vessels. In this paper, a new mathematical model has been developed based on pressure distribution. This model has been provided for two different situations: (1) for a situation in which all forces pass through the center of gravity and (2) for a situation in which forces don not necessarily pass through the center of gravity. Two algorithms have been designed for the governing equations. Computational results have been presented in the form of trim angle, total pressure, hydrodynamic and hydrostatic lift coefficients, spray apex and total resistance which includes frictional, spray and induced resistances. Accuracy of the model has been verified by comparing the numerical findings against the results of Savitsky's method and available experimental data. Good accuracy is displayed. Furthermore, effects of deadrise angle on trim angle of the craft, position of spray apex and resistance have been investigated.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I2.22351","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514959","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 : 2015-12-30DOI: 10.3329/JNAME.V12I2.23638
C. Sulochana, N. Sandeep
In this study we analyzed the magnetohydrodynamic forced convective flow of a nanofluid over a slendering stretching sheet in porous medium in presence of thermal radiation and slip effects. We presented dual solutions for no-slip and Navier slip conditions. Using self similarity transformation, the governing partial differential equations are transformed into nonlinear ordinary differential equations and solved numerically using bvp5c Matlab package. The effects of dimensionless governing parameters on velocity and temperature profiles of the flow are discussed with the help of graphs. Numerical computations are carried out and discussed for skin friction coefficient and local Nusselt number. We found an excellent agreement of the present results with the existed results under some special conditions. Results indicate that the dual solutions exist only for certain range of velocity slip parameter. It is also found that the heat transfer performance is high in presence of velocity slip effect.
{"title":"Dual solutions for radiative MHD forced convective flow of a nanofluid over a slendering stretching sheet in porous medium","authors":"C. Sulochana, N. Sandeep","doi":"10.3329/JNAME.V12I2.23638","DOIUrl":"https://doi.org/10.3329/JNAME.V12I2.23638","url":null,"abstract":"In this study we analyzed the magnetohydrodynamic forced convective flow of a nanofluid over a slendering stretching sheet in porous medium in presence of thermal radiation and slip effects. We presented dual solutions for no-slip and Navier slip conditions. Using self similarity transformation, the governing partial differential equations are transformed into nonlinear ordinary differential equations and solved numerically using bvp5c Matlab package. The effects of dimensionless governing parameters on velocity and temperature profiles of the flow are discussed with the help of graphs. Numerical computations are carried out and discussed for skin friction coefficient and local Nusselt number. We found an excellent agreement of the present results with the existed results under some special conditions. Results indicate that the dual solutions exist only for certain range of velocity slip parameter. It is also found that the heat transfer performance is high in presence of velocity slip effect.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I2.23638","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514966","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 : 2015-12-30DOI: 10.3329/JNAME.V12I2.25269
D. Mythili, R. Sivaraj, Mohammad Mehdi Rashidi, Zhigang Yang
The present investigation deals with the study of unsteady, free convective Casson fluid flow over a vertical cone saturated with porous medium in the presence of non-uniform heat source/sink, high order chemical reaction and cross diffusion effects. The numerical computation for the governing equations has been performed using an implicit finite difference method of Crank-Nicolson type. The influence of various physical parameters on velocity, temperature and concentration distributions is illustrated graphically and the physical aspects are discussed in detail. Results indicate that temperature dependent heat source/sink plays a vital role on controlling the heat transfer however the surface-dependent heat source/sink also has notable influence on the heat transfer characteristics. It is to be noted that high order chemical reaction has the tendency to dilute the influence of chemical reaction parameter on the species concentration.
{"title":"CASSON FLUID FLOW OVER A VERTICAL CONE WITH NON- UNIFORM HEAT SOURCE/SINK AND HIGH ORDER CHEMICAL REACTION","authors":"D. Mythili, R. Sivaraj, Mohammad Mehdi Rashidi, Zhigang Yang","doi":"10.3329/JNAME.V12I2.25269","DOIUrl":"https://doi.org/10.3329/JNAME.V12I2.25269","url":null,"abstract":"The present investigation deals with the study of unsteady, free convective Casson fluid flow over a vertical cone saturated with porous medium in the presence of non-uniform heat source/sink, high order chemical reaction and cross diffusion effects. The numerical computation for the governing equations has been performed using an implicit finite difference method of Crank-Nicolson type. The influence of various physical parameters on velocity, temperature and concentration distributions is illustrated graphically and the physical aspects are discussed in detail. Results indicate that temperature dependent heat source/sink plays a vital role on controlling the heat transfer however the surface-dependent heat source/sink also has notable influence on the heat transfer characteristics. It is to be noted that high order chemical reaction has the tendency to dilute the influence of chemical reaction parameter on the species concentration.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I2.25269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69515449","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 : 2015-06-30DOI: 10.3329/JNAME.V12I1.19719
U. Campora, M. Capelli, C. Cravero, R. Zaccone
The paper presents the application of artificial neural network for simulation and diagnostic purposes applied to a gas turbine powered marine propulsion plant. A simulation code for the propulsion system, developed by the authors, has been extended to take into account components degradation or malfunctioning with the addition of performance reduction coefficients. The above coefficients become input variables to the analysis method and define the system status at a given operating point. The simulator is used to generate databases needed to perform a variable selection analysis and to tune response surfaces for both direct (simulation) and inverse (diagnostic) purposes. The application of the methodology to the propulsion system of an existing frigate version demonstrate the potential of the approach.
{"title":"Metamodels of a gas turbine powered marine propulsion system for simulation and diagnostic purposes","authors":"U. Campora, M. Capelli, C. Cravero, R. Zaccone","doi":"10.3329/JNAME.V12I1.19719","DOIUrl":"https://doi.org/10.3329/JNAME.V12I1.19719","url":null,"abstract":"The paper presents the application of artificial neural network for simulation and diagnostic purposes applied to a gas turbine powered marine propulsion plant. A simulation code for the propulsion system, developed by the authors, has been extended to take into account components degradation or malfunctioning with the addition of performance reduction coefficients. The above coefficients become input variables to the analysis method and define the system status at a given operating point. The simulator is used to generate databases needed to perform a variable selection analysis and to tune response surfaces for both direct (simulation) and inverse (diagnostic) purposes. The application of the methodology to the propulsion system of an existing frigate version demonstrate the potential of the approach.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I1.19719","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514593","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 : 2015-06-30DOI: 10.3329/JNAME.V12I1.22670
A. Sarkar, R. N. Rai, S. C. Saha
In this study, a Numerical model is carried out to study the effect of welding parameters on the temperature variations in Submerged Arc Welding process (SAW) with moving heat source model (Gaussian distribution) by using finite difference method (FDM). The proposed method is validated from the experimental results and found is in good agreement with results obtained by experimental. The mathematical model of transient thermal is also recognized to simulate Peak temperature. Finally Parametric effects on temperature profiles based on numerical results, are carried out for different weld parameters including welding speed, heat input, and plate thickness. It has been shown that all those parameters are playing an essential role in affecting the temperature distribution.
{"title":"A study of parametric effects on thermal profile of submerged arc welding process","authors":"A. Sarkar, R. N. Rai, S. C. Saha","doi":"10.3329/JNAME.V12I1.22670","DOIUrl":"https://doi.org/10.3329/JNAME.V12I1.22670","url":null,"abstract":"In this study, a Numerical model is carried out to study the effect of welding parameters on the temperature variations in Submerged Arc Welding process (SAW) with moving heat source model (Gaussian distribution) by using finite difference method (FDM). The proposed method is validated from the experimental results and found is in good agreement with results obtained by experimental. The mathematical model of transient thermal is also recognized to simulate Peak temperature. Finally Parametric effects on temperature profiles based on numerical results, are carried out for different weld parameters including welding speed, heat input, and plate thickness. It has been shown that all those parameters are playing an essential role in affecting the temperature distribution.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I1.22670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514500","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 : 2015-06-30DOI: 10.3329/JNAME.V12I1.21812
P. Dey, A. Sarkar, A. Das
Heat transfer due to forced convection of copper water based nanofluid in the presence of buoyancy has been predicted by the Artificial Neural network (ANN) Gene Expression Programming (GEP). The present nanofluid is formed by mixing copper nano particles in water and the volume fractions are considered here are 0% to 15% and the Reynolds number are varying from 80 to 180. The buoyancy effect is done by introducing Richardson number (Ri) as 1 and -1. The back propagation algorithm is used to train the network. The present ANN and GEP models are trained by the input and output data which has been obtained from the numerical simulation, performed in finite volume based Computational Fluid Dynamics (CFD) commercial software Fluent. The numerical simulation based results are compared with the back propagation based ANN and GEP results. It is found that the mixed convection heat transfer of water based nanofluid can be predicted correctly by both ANN and GEP but GEP is found more efficient. It is also observed that the back propagation ANN and GEP both can predict the heat transfer characteristics of nanofluid very quickly compared to standard CFD method.
{"title":"Prediction of unsteady mixed convection over circular cylinder in the presence of nanofluid- A comparative study of ANN and GEP","authors":"P. Dey, A. Sarkar, A. Das","doi":"10.3329/JNAME.V12I1.21812","DOIUrl":"https://doi.org/10.3329/JNAME.V12I1.21812","url":null,"abstract":"Heat transfer due to forced convection of copper water based nanofluid in the presence of buoyancy has been predicted by the Artificial Neural network (ANN) Gene Expression Programming (GEP). The present nanofluid is formed by mixing copper nano particles in water and the volume fractions are considered here are 0% to 15% and the Reynolds number are varying from 80 to 180. The buoyancy effect is done by introducing Richardson number (Ri) as 1 and -1. The back propagation algorithm is used to train the network. The present ANN and GEP models are trained by the input and output data which has been obtained from the numerical simulation, performed in finite volume based Computational Fluid Dynamics (CFD) commercial software Fluent. The numerical simulation based results are compared with the back propagation based ANN and GEP results. It is found that the mixed convection heat transfer of water based nanofluid can be predicted correctly by both ANN and GEP but GEP is found more efficient. It is also observed that the back propagation ANN and GEP both can predict the heat transfer characteristics of nanofluid very quickly compared to standard CFD method.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I1.21812","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514890","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 : 2015-06-30DOI: 10.3329/JNAME.V12I1.12910
M. Uddin, Aki Farhana, M. A. Alim
In the present paper, the effect of magneto-hydrodynamic (MHD) on mixed convection flow within a lid-driven triangular cavity has been numerically investigated. The bottom wall of the cavity is considered as heated. Besides, the left and the inclined wall of the triangular cavity are assumed to be cool and adiabatic. The cooled wall of the cavity is moving up in the vertical direction. The developed mathematical model is governed by the coupled equations of continuity, momentum and energy to determine the fluid flow and heat transfer characteristics in the cavity as a function of Rayleigh number, Hartmann number and the cavity aspect ratio. The present numerical procedure adopted in this investigation yields consistent performance over a wide range of parameters Rayleigh number Ra (103-104), Prandtl number Pr (0.7 - 3) and Hartmann number Ha (5 - 50). The numerical results are presented in terms of stream functions, temperature profile and Nussult numbers. It is found that the streamlines, isotherms, average Nusselt number, average fluid bulk temperature and dimensionless temperature in the cavity strongly depend on the Rayleigh number, Hartmann number and Prandtl number.
{"title":"Numerical study of magneto-hydrodynamic (MHD) mixed convection flow in a lid-driven triangular cavity","authors":"M. Uddin, Aki Farhana, M. A. Alim","doi":"10.3329/JNAME.V12I1.12910","DOIUrl":"https://doi.org/10.3329/JNAME.V12I1.12910","url":null,"abstract":"In the present paper, the effect of magneto-hydrodynamic (MHD) on mixed convection flow within a lid-driven triangular cavity has been numerically investigated. The bottom wall of the cavity is considered as heated. Besides, the left and the inclined wall of the triangular cavity are assumed to be cool and adiabatic. The cooled wall of the cavity is moving up in the vertical direction. The developed mathematical model is governed by the coupled equations of continuity, momentum and energy to determine the fluid flow and heat transfer characteristics in the cavity as a function of Rayleigh number, Hartmann number and the cavity aspect ratio. The present numerical procedure adopted in this investigation yields consistent performance over a wide range of parameters Rayleigh number Ra (103-104), Prandtl number Pr (0.7 - 3) and Hartmann number Ha (5 - 50). The numerical results are presented in terms of stream functions, temperature profile and Nussult numbers. It is found that the streamlines, isotherms, average Nusselt number, average fluid bulk temperature and dimensionless temperature in the cavity strongly depend on the Rayleigh number, Hartmann number and Prandtl number.","PeriodicalId":55961,"journal":{"name":"Journal of Naval Architecture and Marine Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3329/JNAME.V12I1.12910","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69514527","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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