Couette flow and heat transfer between parallel plates in a rarefied gas

2015 ◽  
Vol 7 (3) ◽  
pp. 294-302 ◽  
Author(s):  
S. L. Gorelov ◽  
Vuong Van Tien
Author(s):  
Ahmada Omar Ali ◽  
Oluwole Daniel Makinde ◽  
Yaw Nkansah-Gyekye

Purpose – The purpose of this paper is to investigate numerically the unsteady MHD Couette flow and heat transfer of viscous, incompressible and electrically conducting nanofluids between two parallel plates in a rotating channel. Design/methodology/approach – The nanofluid is set in motion by the combined action of moving upper plate, Coriolis force and the constant pressure gradient. The channel rotates in unison about an axis normal to the plates. The nonlinear governing equations for velocity and heat transfer are obtained and solved numerically using semi-discretization, shooting and collocation (bvp4c) techniques together with Runge-Kutta Fehlberg integration scheme. Findings – Results show that both magnetic field and rotation rate demonstrate significant effect on velocity and heat transfer profiles in the system with Cu-water nanofluid demonstrating the highest velocity and heat transfer efficiency. These numerical results are in excellent agreements with the results obtained by other methods. Practical implications – This paper provides a very useful source of information for researchers on the subject of hydromagnetic nanofluid flow in rotating systems. Originality/value – Couette flow of nanofluid in the presence of applied magnetic field in a rotating channel is investigated.


2001 ◽  
Author(s):  
Hong Xue ◽  
Ling Xie ◽  
S. K. Chou

Abstract Gaseous flow encountered in micro/nano electromechanical systems experiences change in Kn number across a wide range of flow regime due to variation in characteristic length in the system and significant compressibility of the rarefied gas. In this study, we attempt to develop a general, physics-based model to predict the flow and heat transfer in the slip and transition regimes. Such an extension is constructed on the fact that Chapman-Enskog’s approximation of the Boltzmann equation can be revised using a function of Kn number as a perturbation. Velocity slip and temperature jump at the solid boundaries are modified accordingly. Rarefaction effects on dynamic viscosity and thermal conductivity are considered. As a first step to evaluate the model, it is applied to the simplest shear-driven flow, micro Couette flow. Compared with the results of DSMC, satisfactory agreement has been achieved in a wide range of Kn and Ma numbers.


2019 ◽  
Vol 6 (4) ◽  
pp. 483-490 ◽  
Author(s):  
Md Tusher Mollah ◽  
Muhammad Minarul Islam ◽  
Sheela Khatun ◽  
Md Mahmud Alam

2008 ◽  
Author(s):  
Yan-Hui Feng ◽  
Ai-Guo Wang ◽  
Lin Lin ◽  
Xin-Xin Zhang ◽  
Xin Liu

The flow and heat transfer of rarefied gas in rough microchannels, which are confined between two infinite large parallel plates with uniformly distributed triangular rough elements, are simulated by DSMC method with Delaunay triangulation meshes. Analysis and comparison are carried out on smooth and rough channels with rough elements of different size or/and distribution density. Roughness in micro-channels affect the gas flow and heat transfer greatly. As the size or/and the number of rough elements increases, the gas velocity jumps more seriously, even being accompanied by some vortices; furthermore, the gas temperature increases, but both the mass flux and the heat transfer rate decrease. In the flow direction, the gas temperature rises first and then falls; the local pressure increases at the windward of rough elements and decreases at the leeward side; moreover, the heat flux at the surface shows violent fluctuation, that is, the heat flux at the rough element surface is much smaller than that at the channel wall surface.


2010 ◽  
Vol 26 (4) ◽  
pp. 525-532 ◽  
Author(s):  
J. C. Umavathi ◽  
I-C. Liu ◽  
J. Prathap Kumar

ABSTRACTAn analysis of the Poiseuille-Couette flow of two immiscible fluids between inclined parallel plates is investigated. One of the fluids is assumed to be electrically conducting while the other fluid and channel walls are assumed to be electrically insulating. The viscous and Ohmic dissipation terms are taken into account in the energy equation. The coupled nonlinear equations are solved both analytically valid for small values of the product of Prandtl number and Eckert number (= ε) and numerically valid for all ε. Solutions for large ε reveal a marked change on the flow and rate of heat transfer. The effects of various parameters such as Hartmann number, Grashof number, angle of inclination, ratios of viscosities, widths and thermal conductivities are presented and discussed in detail.


1987 ◽  
Vol 109 (1) ◽  
pp. 25-30 ◽  
Author(s):  
K. M. Kelkar ◽  
S. V. Patankar

Fluid flow and heat transfer in two-dimensional finned passages were analyzed for constant property laminar flow. The passage is formed by two parallel plates to which fins are attached in a staggered fashion. Both the plates are maintained at a constant temperature. Streamwise periodic variation of the cross-sectional area causes the flow and temperature fields to repeat periodically after a certain developing length. Computations were performed for different values of the Reynolds number, the Prandtl number, geometric parameters, and the fin-conductance parameter. The fins were found to cause the flow to deflect significantly and impinge upon the opposite wall so as to increase the heat transfer significantly. However, the associated increase in pressure drop was an order of magnitude higher than the increase in heat transfer. Streamline patterns and local heat transfer results are presented in addition to the overall results.


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