The effect of pulsation on the heat transfer rates, for turbulent water stream with upstream pulsation of different amplitudes, in a double-pipe heat exchanger for both parallel and counter flows, with cold water on the shell side, was investigated. Pulsation frequencies, with using a reciprocating device, ranged up to 260 cycles per minute (up to 4.3 Hz) and 5 different displacement amplitudes...

In this paper, we present an experimental investigation of pool boiling heat transfer on multiscale (micro/ nano) functionalized metallic surfaces. Heat transfer enhancement in metallic surfaces is very important for large scale high heat flux applications like in the nuclear power industry. The multiscale structures were fabricated via a femtosecond laser surface process (FLSP) technique, whic...

a r t i c l e i n f o a b s t r a c t Heat-transfer enhancement in a uniformly heated slot mini-channel due to vortices shed from an adiabatic circular cylinder is numerically investigated. The effects of gap spacing between the cylinder and bottom wall on wall heat transfer and pressure drop are systemically studied. Numerical simulations are performed at Re = 100, 0.1 Pr 10 and a blockage rat...

A theoretical analysis has been made to explore thermal entrance region heat transfer in nanofluids. The numerical model used in this paper is based on the Buongiorno model for convective heat transfer in nanofluids with modifications to fully account for the effects of nanoparticles volume fraction distributions on the continuity, momentum and energy equations. Numerical investigations have be...

This paper discusses the study of parameters for improving heat transfer a borehole exchanger ground source pump application. The efficiency was carried out based on an experimental prototype developed by authors. A mathematical model has been calculating three-dimensional equations and mass in porous medium. numerical solution using COMSOL Multiphysics software. calculation algorithm verified ...

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 ...

This study numerically investigates heat transfer augmentation using water-based Al₂O₃ and CuO nanofluids flowing in a triangular cross-sectional duct under constant heat flux in laminar flow conditions. The Al₂O₃/water nanofluids with different volume fractions (0.1%, 0.5%, 1%, 1.5%, and 2%) and CuO/water nanofluids with various volume fractions (0.05%, 0.16%, 0.36%, 0.5%, and 0.8%) are employ...