Improvement of heat transfer performance of turbulence promoter ribs

Numerical and experimental approaches were taken to improve the heat transfer performance of V-shaped staggered (VSG) ribs. At first, a numerical method using Large Eddy Simulations (LES) was employed to determine the effect of VSG rib-induced flow on the local heat transfer coefficient distributions. The results revealed that the secondary flows generated by the rib configuration carry cold coolant air from the passage core region to the rib-roughened wall, thus enhancing heat transfer. Conversely, behind each rib there is a recirculation zone that does not contribute to enhanced heat transfer. Based on said results, six types of the advanced V-shaped staggered (AVSG) rib configurations were proposed. The test apparatus employing a comparative method was used to measure the total heat transfer coefficient and pressure loss coefficient of the VSG and AVSG ribs. It was concluded that thermal performance of the most effective type was 25% higher than that of VSG.