Analysis of thermo-hydraulic performance of a solar air heater tube with modern obstacles

Abstract

This paper presents a numerical analysis on turbulent flow and forced-convection characteristics of rectangular solar air heater tube fitted with staggered, transverse, V-shape, modern obstacles on the heated walls. Air, whose Prandtl number is 0.71, is the working fluid used, and the Reynolds number considered equal to 6×103. The governing flow equations are solved using a finite volume approach and the semi-implicit pressure linked equation (SIMPLE) algorithm. With regard to the flow characteristics, the quadratic upstream interpolation for convective kinetics differencing scheme (QUICK) was applied, and a second-order upwind scheme (SOU) was used for the pressure terms. The dynamic thermo-energy behavior of the V-shaped baffles with various flow attack angles, i.e., 50◦, 60◦, 70◦, and 80◦ are simulated, analyzed, and compared with those of the conventional flat rectangular baffles with attack value of 90◦. In all situations, the thermal transfer rate was found to be much larger than unity; its maximum value was around 3.143 for the flow attack angle of 90◦ and y = H/2.