Heat transfer downstream of a 3D confined square cylinder under flow pulsation

Abstract

This 3D study deals with the effect that a low Reynolds number (Re) pulsating water flow has on both the heat transfer to the walls of a square section channel in which a square section prism was located, and the associated pumping power. The prism blockage ratio was 2.5/1. Re, based on the prism cross-section height, varied from 100 up to 200. The inflow velocity profile was sinusoidal. Taking St₀ as the Strouhal number of the vortex shedding downstream of the prism at Re 100, the inflow Strouhal of the pulsating cases varied between 0.125 St₀ and 4 St₀. The results show that, for this particular geometry and parametric space, flow pulsation generally enhances heat transfer although its extent depends on Re and pulsation frequency. In the most favorable case, heat transfer doubles as compared to the clean channel case at the expense of tripling the pumping power.