Unsteady Numerical Simulation of Turbulent Forced Convection in a Rectangular Pipe Provided With Waved Porous Baffles

Abstract

Numerical simulations of flow and heat transfer in a serpentine heat exchanger configuration are presented to demonstrate application of porous media techniques in heat exchanger analyses. In this study, steady-state 3D turbulent forced convection flow and heat transfer characteristics in a rectangular pipe with baffles attached inside pipe have been numerically investigated under constant wall heat flux boundary condition. Numerical study has been carried out for Reynolds number of 20000-50,000, Prandtl number of 0.71, baffle distances h/Dh of 1/3 and 2/3, and baffle thickness e of 1/12, 2/3. It is observed that rectangular pipe having waved baffles has a higher Nusselt number and friction factor compared to the smooth rectangular pipe without baffles. Periodically fully developed conditions are obtained after a certain module. Maximum thermal performance factor is obtained for the baffle waved. Results show that baffle distance, waved porous baffle, and Reynolds number play important role on both flow and heat transfer characteristics. All the numerical results are correlated within accuracy of ±2% and ±2.5% for average Nusselt number and friction factor, respectively.

Heat transfer investigation of non-newtonian fluid flow in anannular pipe embedded with porous discs: A turbulent study

“…The macroscopic transport equations for the turbulent kinetic energy and dissipation rate in the porous medium are as follow [28,30]:…”

Transient analysis of convective-radiative heat transfer through porous fins with temperature-dependent thermal conductivity and internal heat generation

“…Porous mediums which are constructed with high thermal conductivity materials like metal foams can increase the fluid-solid contact which results in enhancing the heat transfer [2][3][4]. In recent years, Using of porous fins to enhance the performance of thermal systems like photovoltaic-thermal (PVT) systems, high power semiconductor devices, electronic cooling systems, heat exchangers, enhancing of the heat transfer of fluids in enclosures, pipes and channels, thermal insulators etc, [5][6][7][8][9][10][11][12] has been an attractive subject for many researchers. Kiwan and Al-Namir [1] employed finite element method to analyze the enhancing performance of porous fins compared to solid fins and demonstrated that in the large Darcy numbers, the effect of the Rayleigh number is more significant.…”