The study of flow and heat transfer over rotating circular disks is of great practical importance in understanding the cooling of rotatory machinery such as turbines, electric motors and design and manufacturing of computer disk drives. This paper presents an analysis of the flow and heat transfer over a heated infinite permeable rough disk. Boundary-layer approximation reduces the elliptic Nav...

Heat and mass transfer, in this paper, is considered in one-row heat exchanger, that fins are hotter than air flow and water is added to fins. Related governing equations are derived by analyzing a two-dimension model in a unique cell of a heat exchange. These equations are numerically solved by finite difference method. Heat transfer and efficiency under partially wet surface are calculated by...

This reports the study on the flow behaviour, heat transfer and contamination distribution in a room. For this purpose the 3-D incompressible Navier-Stokes equations, energy equation and a mass transfer equation which model the concentration of contamination have been applied. For turbulence simulation the two equation standard k-  turbulence model was employed. By means of SIMPLE algorithm the...

in this paper, the effects of baffle on thermal characteristics of combined convection-radiation heat transfer in laminar flow adjacent to an inclined backward facing step (bfs) in a horizontal duct are investigated. a baffle is mounted on the top wall of channel downstream side of step. in this study, the fluid is treated as a gray, absorbing, emitting and scattering medium; therefore, in the ...

the present article focuses on the evaluation of a first-moment closure model applicable to film cooling flow and heat transfer computations. the present first-moment closure model consists of a higher level of turbulent heat flux modeling in which two additional transport equations for temperature variance kθ and its dissipation rate εθ are considered. it not only employs a time scale that is ...

A numerical study has been carried out on the momentum and heat transfer characteristics of an incompressible magnetohydrodynamic boundary layer slip flow over a flat plate with both viscous and ohmic dissipations. Momentum boundary layer equation takes care of the magnetic field while the ohmic and viscous dissipations are accounted for by the thermal boundary layer equation. The governing equ...

Basic understanding of the process of coolant heat transfer inside an engine is an indispensable prerequisite to devise an infallible cooling strategy. Coolant flow and its heat transfer affect the cooling efficiency, thermal load of heated components, and thermal efficiency of a diesel engine. An efficient approach to studying cooling system for diesel engine is a 3D computational fluid dynami...

In many problems related to cryopreservation of living cells and tissues, the formation of ice in intra and extracellular liquids plays very important role. There are many models predicting the homogeneous ice nucleation an formation of dendrites. Nevertheless, the application of such models requires fitting parameters and verifications trough measurements of the ice content during freezing. Th...

In this study an analytical model for open loop pulsating heat pipes (PHPs) is presented. The model predicts the effect of different parameters such as evaporator temperature, length of evaporator, filling ratio, number of turn and tube diameter on PHP's performance. The governing equations in two phase flow including mass, momentum and energy equations are solved for both one dimensional liqu...

The most important reason for the design of curved tubes is increasing the heat transfer between the fluid and the wall which has provided many applications in various industries such as air conditioning, micro-electric, heat exchangers and etc. The aim of this study is numerical investigation of nano fluids flow in spiral tubes with injection of base fluid in different Reynolds numbers. Accord...