Journal of Applied Fluid Mechanics1735-35727320140701Mixed Convection Flow from Vertical Plate Embedded in Non-Newtonian Fluid Saturated Non- Darcy Porous Medium with Thermal Dispersion-Radiation and Melting Effects385394145210.36884/jafm.7.03.19339ENJ. S. R. PrasadV.R.Siddhartha Eng College, Dept of Mathematics, Vijayawada, A.P, 520006, IndiaK. HemalathaV.R.Siddhartha Eng College, Dept of Mathematics, Vijayawada, A.P, 520006, IndiaB. D. C. N. PrasadP.V.P Siddhartha Institute of Technology, Dept of Computer Applications, Vijayawada, A.P, 520006, IndiaJournal Article19700101We analyzed in this paper the problem of mixed convection along a vertical plate in a non-Newtonian fluid saturated non-Darcy porous medium in the presence of melting and thermal dispersion-radiation effects for aiding and opposing external flows. Similarity solution for the governing equations is obtained for the flow equations in steady state. The equations are numerically solved by using Runge-Kutta fourth order method coupled with shouting technique. The effects of melting, thermal dispersion, radiation, temperature ratio, inertia and mixed convection on velocity distribution and temperature are examined for aiding and opposing external flows.https://www.jafmonline.net/article_1452_46ef6a582fb41cdf5a33d3ee4d028681.pdfJournal of Applied Fluid Mechanics1735-35727320140701CFD Investigation of Influences of Reverse Textures on Bearing Surface of a Journal Bearing395399145310.36884/jafm.7.03.19364ENS. MishraBhilai Institute of Technology, Durg, Chhattisgarh, 491001, India0000-0001-8616-2606A. ChoudhuryBhilai Institute of Technology, Durg, Chhattisgarh, 491001, IndiaS. SahuBhilai Institute of Technology, Durg, Chhattisgarh, 491001, IndiaJournal Article19700101It has always been the subject of interest and research to find out most efficient method to minimize the frictional loss of any mating surface in any mechanism. But it has been identified that only improvement of lubricating material cannot help much. For this reason research on design modification was started and still going on to optimize the design of mating surfaces so that losses be minimum. In this paper a research has been done on the design of bearing surface of a journal bearing. Journal bearing is a very important part of many machines specially turbines used in Power generation and rolling mills used in steel making sectors. By modifying the design of the bearing surface, load carrying capacity of a journal bearing can be increased and thus its performance can be improved. It is proved by many researches that, by putting cylindrical dimples on bearing surface the performance of a journal bearing can be increased. To measure the performance of a journal bearing three parameters are usually used. Those are, (i) Load Carrying Capacity, (ii) Frictional resisting force and (iii) Ratio of Frictional resistance and Load carrying capacity, which is called Frictional coefficient. In this work a modification has been done on the work of Cupillard. Cupillard considered only the cylindrical dimples for the sake of manufacturing simplicity, but in this work a different configuration of dimple has been considered and its influence on bearing performance has been studied. It is proved by many researches that, by putting cylindrical dimples on bearing surface the performance of a journal bearing can be increased. To measure the performance of a journal bearing three parameters are usually used. Those are, (i) Load Carrying Capacity, (ii) Frictional resisting force and (iii) Ratio of Frictional resistance and Load carrying capacity, which is called Frictional coefficient. In this work a modification has been done on the work of Cupillard at all (reference [9]). Cupillard considered only the cylindrical dimples for the sake of manufacturing simplicity, but in this work a different configuration of dimple has been considered and its influence on bearing performance has been studied.https://www.jafmonline.net/article_1453_5a1e26bd67174d4fd8b2432a45394e32.pdfJournal of Applied Fluid Mechanics1735-35727320140701A Study of the Asymptotic Equilibrium Behavior in Stratified Turbulence Submitted to Horizontal Shear401413145410.36884/jafm.7.03.19403ENL. Thamri NaffoutiLaboratoire de Mécanique des Fluides, Département de Physique, Faculté des Sciences de TunisT. LiliLaboratoire de Mécanique des Fluides, Département de Physique, Faculté des Sciences de TunisM. BouzaianeLaboratoire de Mécanique des Fluides, Département de Physique, Faculté des Sciences de TunisJournal Article19700101In this work, the asymptotic equilibrium behaviour of dimensionless parameters in stably stratified turbulence submitted to a horizontal shear is studied using two different methods. The first one is an analytic method and is based on linear solutions obtained when non linear effects of pressure and viscosity are neglected. The Laplace Transform is used for integrating differential system. The principal result of this first part of our work is the existence of asymptotic equilibrium states at high shear for all non dimensionless parameters. The second method is a numerical one and is based on a second-order modeling of equations. The Speziale Sarkar and Gatski (SSG) model is retained for pressure-strain correlation and dissipation time evolution equation, whereas, three of the most known second-order models are retained for the scalar field. The principal result of this second part is the big contribution of the SSG models for predicting asymptotic equilibrium states of non dimensional parameters.https://www.jafmonline.net/article_1454_cd8989cb143662704195fd19982c65ff.pdfJournal of Applied Fluid Mechanics1735-35727320140701Numerical Simulation of Magnetohydrodynamic Forced Convective Boundary Layer Flow past a Stretching/Shrinking Sheet Prescribed with Variable Heat Flux in the Presence of Heat Source and Constant Suction415423145510.36884/jafm.7.03.19411ENS. P. Anjali DeviDepartment of Applied Mathematics, Bharathiar University, Coimbatore, Tamil Nadu, India.J. W. S. RajDepartment of Applied Mathematics, Bharathiar University, Coimbatore, Tamil Nadu, India.Journal Article19700101A study has been carried out on MHD boundary layer forced convection flow along a shrinking surface with variable heat flux in the presence of heat source. The flow is generated due to linear shrinking of the sheet and is influenced by uniform transverse magnetic field. The basic boundary layer momentum and heat transfer equations, which are nonlinear partial differential equations, are converted into nonlinear ordinary differential equations by means of similarity transformation. Numerical solution of the resulting boundary value problem is obtained using Nachtsheim Swigert shooting iteration scheme for the satisfaction of asymptotic boundary conditions along with the Fourth Order Runge Kutta method. The effects of suction parameter, magnetic parameter, Prandtl number, heat source parameter, stretching/shrinking parameter and heat flux parameter on velocity and temperature are shown in several plots. The results are in good agreement with the earlier published works under some limiting cases. Skin friction coefficient and wall temperature are also explored for typical values of the parameter involved in the study.https://www.jafmonline.net/article_1455_4c45b80a20d1e7127a9a4945d566bfa4.pdfJournal of Applied Fluid Mechanics1735-35727320140701Effect of Non-Uniform Heat Generation on Unsteady MHD Non-Darcian Flow over a Vertical Stretching Surface with Variable Properties425434145610.36884/jafm.7.03.19414ENM. MuthtamilselvanDepartment of Applied Mathematics, Bharathiar University, Coimbatore-641 046, IndiaD. PrakashDepartment of Applied Mathematics, Bharathiar University, Coimbatore-641 046, IndiaD. H. DohDivision of Mechanical and Energy Systems Engineering, College of Engineering, Korea Maritime University, Busan 606-791, South KoreaJournal Article19700101The effect of non-uniform heat generation on an unsteady MHD laminar boundary layer flow of viscous, incompressible fluid over a vertical stretching plate embedded in a sparsely packed porous medium is investigated numerically. The flow in the porous medium is governed by Brinkman-Forchheimer extended Darcy model. The variation of porosity, permeability and thermal conductivity is assumed. By applying similarity analysis, the governing partial differential equations are transformed into a set of time dependent non-linear coupled ordinary differential equations and they are solved by Runge-Kutta Fehlberg Method along with shooting technique. The effects of governing parameters on the dimensionless velocity and temperature distributions for uniform permeability (UP) and variable permeability (VP) of the porous medium are discussed graphically. Also, the local skin friction coefficient and the rate of heat transfer are computed for various pertinent parameters governing the problem. Moreover, the numerical results obtained in this study is compared with the existing literature and found they are in good agreement.https://www.jafmonline.net/article_1456_80c560fc178686a252e4e31f6716af03.pdfJournal of Applied Fluid Mechanics1735-35727320140701A Novel Strategy for Designing and Manufacturing a Fixed Wing MAV for the Purpose of Increasing Maneuverability and Stability in Longitudinal Axis435446145710.36884/jafm.7.03.19415ENM. RadmaneshDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, IranO. NematollahiDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, IranM. Nili-AhmadabadiDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, IranM. HassanalianDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, IranJournal Article19700101In this study, a novel simple strategy is proposed to choose and accommodate an airfoil based on the effects of airfoil type and plan-form shape on the flight performance of a micro air vehicle. In this strategy, after defining flight mission, the weight of the micro air vehicle is estimated and then, aerodynamic parameters and thrust force are calculated. In the next step, some different plan-forms and airfoils are investigated to be selected for decreasing the stall region in high attack anglesby open source software named XFLR5. Having calculated the aerodynamic center, the pitching moment needed to stabilize the micro air vehicle is computed. Due to the static margin, the airfoil camber line is changed to stabilize the micro air vehicle and then, its thickness is improved to reach to a high aerodynamic characteristic. To evaluate the software results, some flight tests are performed which then compared to the software results that show a good agreement. Finally, some adjustments and improvements are made on the micro air vehicle and then, its performance is obtained by the flight tests. The flight test results show it has an excellent aerodynamic performance, stability and maneuverability.https://www.jafmonline.net/article_1457_bb20565819d4421061e7b28ab2e1f28f.pdfJournal of Applied Fluid Mechanics1735-35727320140701Diffusion-Thermo and Thermal-diffusion Effects on MHD Visco-Elastic Fluid Flow over a Vertical Plate447458145810.36884/jafm.7.03.20296END. YasminMathematics Discipline, Khulna University, Khulna-9208, BangladeshT. AhmedMathematics Discipline, Khulna University, Khulna-9208, BangladeshN. N. AnikaMathematics Discipline, Khulna University, Khulna-9208, BangladeshM. M. Mukitul HasanDepartment of Mathematics, Khulna Public College, Khulna-9000, BangladeshM. Mahmud AlamMathematics Discipline, Khulna University, Khulna-9208, BangladeshJournal Article19700101Unsteady MHD visco-elastic fluid flow has been studied numerically under the action of transverse magnetic field with diffusion-thermo and thermal diffusion for small magnetic Reynolds number. The governing equations are non-dimensionalized by usual non-dimensional variables. The obtained equations are solved by explicit finite difference technique. The solutions of the dimensionless velocity, temperature and concentration equations are shown graphically. The effects of parameters on the shear stress, Nusselt number and Sherwood number are discussed in graphical form. Finally, a qualitative comparison with previous work is tabulated.https://www.jafmonline.net/article_1458_30feab353d0dca7f746c2dcc27fe2e20.pdfJournal of Applied Fluid Mechanics1735-35727320140701Linear Stability Analysis of Double Diffusive Convection in a Horizontal Sparsely Packed Rotating Anisotropic Porous Layer in Presence of Soret Effect459471145910.36884/jafm.7.03.20309ENS. N. GaikwadDepartment of Mathematics, Gulbarga University, Jnana Ganga Campus, Gulbarga 585 106, India.S. S. KambleDepartment of Mathematics, Government First Grade College, Chittapur – 585 211, India.Journal Article19700101In this paper, we have investigated theoretically the effect of Soret parameter on the onset of double diffusive rotating anisotropic convection in a horizontal sparsely packed porous layer using linear stability theory which is based on the usual normal mode technique. The Brinkman model that includes the Coriolis term is employed for the momentum equation. The effect of anisotropy parameters, Soret parameter, solute Rayleigh number, Taylor number, Lewis number, Darcy and Darcy Prandtl number on stationary and oscillatory convection is shown graphically.https://www.jafmonline.net/article_1459_33757f65d1651d7259a66a0ea87d936f.pdfJournal of Applied Fluid Mechanics1735-35727320140701Numerical Study of Generalized Three-Dimensional MHD Flow over a Porous Stretching Sheet473483146010.36884/jafm.7.03.20317ENM. HeydariDepartment of Mathematics, Yazd University, Yazd, IranG. B. LoghmaniDepartment of Mathematics, Yazd University, Yazd, IranA. A. DehghanSchool of Mechanical Engineering, Yazd University, Yazd, IranJournal Article19700101In this paper a numerical method for solving generalized three-dimensional magnetohydrodynamic (MHD) flow of an incompressible viscous fluid over a porous stretching sheet is proposed. This approach is based on Legendre pseudo-spectral method with a positive scaling factor and extrapolation. The present method solves the problem on the semi-infinite domain without truncating it to a finite domain. In addition, this method reduces the solution of the problem to solution of a system of algebraic equations. The obtained numerical results are compared with some well-known results to confirm the accuracy and efficiency of the proposed scheme.https://www.jafmonline.net/article_1460_93803351aaea37f756dbe0f0f4bb1ad6.pdfJournal of Applied Fluid Mechanics1735-35727320140701Unsteady Hydromagnetic Flow of a Heat Absorbing Dusty Fluid Past a Permeable Vertical Plate with Ramped Temperature485492146110.36884/jafm.7.03.20341ENM. DasDepartment of Mathematics, School of Applied Sciences, KIIT University, Bhubaneswar-751024, IndiaB. K. MahathaDepartment of Mathematics, School of Applied Sciences, KIIT University, Bhubaneswar-751024, IndiaR. NandkeolyarDepartment of Mathematics, School of Applied Sciences, KIIT University, Bhubaneswar-751024, IndiaB. K. MandalDepartment of Mathematics, Vidya Vihar Institute of Technology, Purnea, IndiaK. SaurabhDepartment of Mathematics, Vidya Vihar Institute of Technology, Purnea, IndiaJournal Article19700101The unsteady flow and heat transfer of a viscous incompressible, electrically conducting dusty fluid past vertical plate under the influence of a transverse magnetic field is studied with a view to examine the combined effects of suction, heat absorption and ramped wall temperature. The temperature of the wall is assumed to have a temporarily ramped profile which goes on increasing up to a certain time limit and then becomes constant. To investigate the effect of rampedness in wall temperature, the solution for the flow past an isothermal wall is also obtained. The governing partial differential equations are solved using Laplace transformation technique in which the inversion is obtained numerically using Matlab. To validate the results of numerical inversion a comparison between the numerical and analytical values of fluid and particle temperatures and Nusselt number is also presented. The effects of pertinent flow parameters affecting the flow and heat transfer are investigated with the help of graphs and tables. It is found that the increase in suction, heat absorption and particle concentration contribute in thinning the thermal and momentum boundary layers and the velocity and temperature for both the fluid and particle phases are higher in the case of a flow past an isothermal plate than that of a flow past a plate with ramped temperature.https://www.jafmonline.net/article_1461_6ff5ea27d64922e042b935da15fa165f.pdfJournal of Applied Fluid Mechanics1735-35727320140701Numerical Study of Sinusoidal Temperature in Magneto- Convection493502146210.36884/jafm.7.03.19566ENH. JamaiLaboratoire d'Energétique et des Transferts Thermique et Massique (LETTM), Département de Physique, Faculté des Sciences de TunisS. O. FakhreddineLaboratoire d'Energétique et des Transferts Thermique et Massique (LETTM), Département de Physique, Faculté des Sciences de TunisH. SammoudaEcole Supérieure des Sciences et de Technologie de Hammam Sousse - Université de SousseJournal Article19700101In this paper we would like to present a numerical study of the effect of magnetic fields on natural convection (magneto-convection) flow of electrically conducting fluid. The 2D square cavity which was studied is subjected to a sinusoidal temperature conditions. The left and the right walls were respectively heated and cooled with a sinusoidal temperature while the top wall was kept thermally insulated. The equations are solved numerically by employing finite element method (MEF) using the software COMSOL Multiphysics. We presented the results in wide range of Hartmann number and Rayleigh number in terms of isotherm contours, velocities fields streamlines, , and in an average and local Nusselt number which varies sinusoidally. Our results are shown to be in good conformity with the available benchmark solutions.https://www.jafmonline.net/article_1462_1064e2fad0af6e480d98b292c6017161.pdfJournal of Applied Fluid Mechanics1735-35727320140701Radiation Effect on MHD Fully Developed Mixed Convection in a Vertical Channel with Asymmetric Heating503512146310.36884/jafm.7.03.19422ENR. PatraDepartment of Applied Mathematics, Vidyasagar University Midnapore 721 102, IndiaS. DasDepartment of Mathematics, University of Gour Banga, Malda 732 103, IndiaR. Nath JanaDepartment of Applied Mathematics, Vidyasagar University Midnapore 721 102, IndiaJournal Article19700101Effects of radiative heat transfer on MHD fully developed mixed convective flow of a viscous incompressible electrically conducting fluid through a vertical channel with asymmetric heating of the walls in the presence of a uniform transverse magnetic field has been studied. An exact solution of the governing equations has been obtained in closed form. It is observed that the velocity field is greatly influenced by the radiative heat transfer as well as bouyancy forces. The induced magnetic field decreases at any point near the left wall and it increases near the right wall of the vertical channel with increase in radiation parameter. Further, an increase in radiation parameter leads to a decrease in the temperature at any point of the channel flow. A limiting consideration of the solutions of the governing equations of the flow are analyzed for Rahttps://www.jafmonline.net/article_1463_bbbeb57ed90f1191552c2517668aa10f.pdfJournal of Applied Fluid Mechanics1735-35727320140701Soret-Dufour Effects on Hydromagnetic Non-Darcy Convective-Radiative Heat and Mass Transfer over a Stretching Sheet in Porous Medium with Viscous Dissipation and Ohmic Heating513523146410.36884/jafm.7.03.20357END. PalDepartment of Mathematics, Siksha-Bhavana, Visva-Bharati University, Santiniketan, West Bengal-731235, IndiaH. MondalDepartment of Mathematics, Bengal Institute of Technology and Management, West Bengal-731236, IndiaJournal Article19700101The present study is devoted to investigate the effects of Soret and Dufour on the mixed convection flow, heat and mass transfer over a stretching sheet in the presence of viscous dissipation, Ohmic heating, thermal radiation in porous medium. Numerical solutions for the coupled governing equations are obtained by using the fifth-order Runge-Kutta-Fehlberg method with shooting technique. Important features of flow, heat and mass transfer characteristics for different values of the physical parameters are analyzed and discussed. Numerical results reveal that the magnetic field and inertia coefficient reduce the skin friction but reverse effects are seen on local Nusselt number.https://www.jafmonline.net/article_1464_1f6089216ae22a684cec62a47626592a.pdfJournal of Applied Fluid Mechanics1735-35727320140701Experimental Investigation of “Why an AC Dielectric Barrier Discharge Plasma Actuator is Preferred to DC Corona Wind Actuator in Boundary Layer Flow Control?”525534146510.36884/jafm.7.03.20378ENG. TathiriDepartment of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranE. EsmaeilzadehHeat & Fluid Research Laboratory, Department of Mechanical Engineering, Tabriz University,Tabriz, IranS. M. MirsajediAssistant Professor Faculty of New Technologies EngineeringShahid Beheshti University Tehran, IranH. Mahdavi MoghaddamDepartment of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranJournal Article19700101In this paper, characteristics of the flow induced in the boundary layer by an AC-Dielectric Barrier Discharge (DBD) plasma actuator are compared against those of a DC-corona wind actuator. This is achieved by visualization of the induced flow using smoke injection and measuring the horizontal induced velocity. Our measurements show that the maximum induced velocity of an AC-DBD actuator is about one order of magnitude larger than that of a DC-corona actuator. For an AC-DBD actuator, the induced velocity is maximized on the plate surface while for a DC-corona actuator the induced velocity peaks at about 20mm above the surface. Using flow visualization, we demonstrate that the induced velocity of an AC-DBD actuator is parallel to the surface, while the induced velocity of a DC-corona actuator has components perpendicular to surface.https://www.jafmonline.net/article_1465_d36efd2eed3ae964e9e95ad89e083f0b.pdfJournal of Applied Fluid Mechanics1735-35727320140701Heated Permeable Stretching Surface in a Porous Medium Using Nanofluids535542146610.36884/jafm.7.03.21368ENM. SheikholeslamiDepartment of Mechanical Engineering, Babol University of Technology, Babol, P.O. Box 484, Islamic Republic of Iran.D. D. GanjiDepartment of Mechanical Engineering, Babol University of Technology, Babol, P.O. Box 484, Islamic Republic of Iran.Journal Article19700101In this article, two-dimensional laminar-forced convection nanofluids flow over a stretching surface in a porous medium has been studied. The governing partial differential equations with the corresponding boundary conditions are reduced to a set of ordinary differential equations with the appropriate boundary conditions using similarity transformation, which is then solved numerically by the fourth order Runge–Kutta integration scheme featuring a shooting technique. Different models of nanofluid based on different formulas for thermal conductivity and dynamic viscosity are used. Different types of nanoparticles as copper, silver, alumina and titanium Oxide with water and Ethylene glycol as their base fluids has been considered. The influence of significant parameters such as nanoparticle volume fraction, kind of nanofluid, Magnetic parameter and Reynolds number on the flow and heat transfer characteristics is discussed. The influence of significant parameters such as Thermal conductivity parameter, volume fraction of the nanoparticles, Permeability parameter, suction/injection parameter and Velocity ratio parameter on the flow and heat transfer characteristics is discussed. It was found that choosing Titanium oxide as the nanoparticle and Ethylene glycol as base fluid proved to have the highest cooling performance for this problem.https://www.jafmonline.net/article_1466_d36efd2eed3ae964e9e95ad89e083f0b.pdfJournal of Applied Fluid Mechanics1735-35727320140701Finite Element Simulation of Forced Convection in a Flat Plate Solar Collector: Influence of Nanofluid with Double Nanoparticles543556146710.36884/jafm.7.03.21416ENR. NasrinDepartment of Mathematics, Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh.M. A. AlimDepartment of Mathematics, Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh.Journal Article19700101This work compares heat loss characteristics across a riser pipe of a flat plate solar collector filled water based nanofluid of double nanoparticles (alumina and copper) with single nanoparticle (alumina). Also this study compares heat transfer phenomena among four nanofluids namely water-copper oxide, water-alumina, water-copper and water-silver nanofluids. Comparisons are obtained by numerically solving assisted convective heat transfer problem of a cross section of flat plate solar collector. Governing partial differential equations are solved using the finite element simulation with Galerkin’s weighted residual technique. The average Nusselt number (Nu) at the top hot wall, average temperature (θav), mean velocity (Vav), percentage of collector efficiency (η), mid-height dimensional temperature (T) for both nanofluid and base fluid through the collector pipe are presented graphically. The results show that the better performance of heat loss through the riser pipe of the flat plate solar collector is found by using the double nanoparticles (alumina and copper) than single nanoparticle (only alumina). When comparing the four nanofluids considering the same solid volume fraction ( = 5%), this study claims that the average Nusselt number for water-Ag nanofluid is higher than others.https://www.jafmonline.net/article_1467_ae04ec3ab35ecbb40b55b5f205d47791.pdf