Thermal performance of four cylinders in different layouts of spacing ratios under cross-flow at Reynolds number of 35000

Abstract

Unsteady numerical investigation of combined influence of longitudinal and transverse spacing between the four cylinders on the heat transfer rate has been conducted with various in-line and the staggered arrangements at constant-heat-flux condition and Reynolds number of 35000. The cross-flow of air under ambient condition past the cylinders was taken. Analysis of drag and lift coefficients, distribution of pressure, and the Nusselt number was conducted while the interpretations was done with the help of vorticity and pathline structures. Three spacing ratios (SL/D)/(ST/D) = 1, 0.58 and 1.78 based on longitudinal to transverse spacing with nine different layouts 1–9 were simulated in a two-dimensional structured O-grid domain that were divided into three groups. A term Heat Transfer Ratio (HTR) was used to compare the thermal performance of various layouts and found out two most favourable layouts 9 and 6; two moderately favourable layouts 4 and 2, and five the least favourable layouts 1, 3, 5, 7 and 8.