Journal of Applied Fluid Mechanics
Isfahan University of Technology
About: Journal of Applied Fluid Mechanics is an academic journal published by Isfahan University of Technology. The journal publishes majorly in the area(s): Mechanics & Turbulence. It has an ISSN identifier of 1735-3572. It is also open access. Over the lifetime, 1344 publications have been published receiving 8492 citations. The journal is also known as: JAFM.
TL;DR: In this paper, the effect of reverting microchannels inside a heat sink on increase of cooling rate as well as their effect of their different configurations on maximum temperature and pressure drop was investigated.
Abstract: This study investigated the effect of reverting microchannels inside a heat sink on increase of cooling rate as well as the effect of their different configurations on maximum temperature and pressure drop. Based on the convection heat transfer mechanism, selection of the embedded microchannels’ configurations including circular, square and triangular ones, was studied for geometric optimization of the discussed heat sinks. The goal was to minimize the thermal resistance through optimizing the geometries. The volume ratio was defined as the ratio of the volume taken up by microchannels to the solid volume (portion of the heat sink not occupied by microchannels) and was considered as 0.05. According to the results, in addition to obtaining a more uniform temperature distribution, reverting channels remarkably reduced the maximum temperature. Moreover, the heat sink with square shape showed less thermal resistance as compared to the other two geometries.
TL;DR: In this paper, a numerical study was carried out by using two different turbulence models at Mach No 16, to identify the influence of turbulence modeling and wing on overall pressure distribution and onset of flow separation.
Abstract: CFD (Computational Fluid Dynamics) Analysis of Delta wing configurations used for supersonic flight regime is a key area of interest for flow control due to coherent vortical structures existing on the leeward side of wing In the present research, a numerical study was carried out by using two different turbulence models at Mach No 16, to identify the influence of turbulence modeling and wing on overall pressure distribution and onset of flow separation Fully structured multi-block grid was used with the grid refinement near the wall to resolve the vortical flow structures accurately Different turbulence models used were SA (Spalart-Allmaras) and kω-SST (Shear-stress Transport) An under prediction in pressure distribution was observed by using SA Turbulence model, in comparison with known experimental data at fixed Mach No The analysis of results presented showed that the height of primary vortex increases by increasing the angle of attack and by keeping the Mach No as fixed Moreover, the vortex formation on cambered wing seems less pronounced as compared with that of sharp wing at high angle of attack
TL;DR: In this article, the effects of low Prandtl number nanofluid in a porous medium were investigated by using Galerkin weighted residuals method for free-free boundaries.
Abstract: Thermal instability in a low Prandtl number nanofluid in a porous medium is investigated by using Galerkin weighted residuals method for free-free boundaries. For porous medium, Brinkman-Darcy modelis applied. The model used for the nanofluid describes the effects of Brownian motion and thermophoresis. Linear stability theory based upon normal mode analysis is employed to find the expression for stationary and oscillatory convection. The effects of Prandtlnumber, Darcy number, Lewis number and modified diffusivity ratio on the stationary convection are investigated both analytically and graphically. The results indicated that the Prandtl and Darcy numbers have a destabilizing effect while the Lewis number and modified diffusivity ratio have a stabilizing effect for the stationary convection.
TL;DR: In this paper, the performance enhancement of a supersonic air intake model through the implementation of blunted leading edge to the cowl lip section of the model is discussed, which can reduce the intensity of shock wave boundary layer interaction occurring at the isolator entry section.
Abstract: This paper discusses the performance enhancement of supersonic air intake model through the implementation of blunted leading edge to the cowl lip section of the model. A supersonic air intake model with sharp cowl leading edge is initially considered to numerically investigate its performance. Mach 3, supersonic intake flow through the base model has been simulated using commercial CFD package Ansys Fluent-15. Comparison of numerical predictions and experimental measurements is presented to demonstrate the correctness and accuracy of numerical frame work followed in the present study. Higher order spatial accuracy of the solver along with suitably refined mesh helped in accurate capturing of the flow field. Modification to the cowl lip is proposed as an effective method to improve the performance of the supersonic air intake. Two different blunted cowl leading edge geometries were investigated to identify the possible enhancement in performance parameters. Improvement in mass capture and combustion stability attained through the use of forward shifted blunt cowl leading edge is presented. It is also revealed through the present study that the blunt cowl leading edge can reduce the intensity of shock wave boundary layer interaction occurring at the isolator entry section. Deviation in total pressure recovery and flow distortion observed with different supersonic air intake models are also discussed with reasons for the same. This study demonstrates the scope of overall improvement in scramjet engine performance through the use of suitably positioned blunt cowl leading edge.
TL;DR: In this article, the magnetohydrodynamic (MHD) three-dimensional boundary layer flow of an incompressible Casson fluid in a porous medium is investigated and heat transfer characteristics are analyzed in the presence of heat generation/absorption.
Abstract: The magnetohydrodynamic (MHD) three-dimensional boundary layer flow of an incompressible Casson fluid in a porous medium is investigated. Heat transfer characteristics are analyzed in the presence of heat generation/absorption. Laws of conservation of mass, momentum and energy are utilized. Results are computed and analyzed for the velocities, temperature, skin-friction coefficients and local Nusselt number.