Heat transfer enhancement and flow characteristics in a rectangular channel having inclined pin arrays mounted on the endwall surface

Abstract This study describes heat transfer and flow characteristics for various angles of inclined-pin staggered arrays in a rectangular channel. The pin array consists of 10 staggered rows of cylindrical pins. Influence of the pin inclined angle is studied at θ = 30o, 45o, 60o, 90o, 120o, 135o, and 150o. A thermochromic liquid crystal sheet is used for temperature measurement. Flow field and heat transfer characteristics are predicted by numerical simulation. From the study, certain pin inclined angles have shown a favorable effect on the heat transfer enhancement with an array of pins. Only pin arrays with inclined angles at θ = 120o and 135o could enhance heat transfer on the surface when compared with conventional right-angle pin. Jet-like flows behind the pin move the counter-rotating vortices with high velocity (CRH) that induce airflow attachment to the heat transfer surface down to the lower surface. So, CRH has a significant effect on heat transfer promotion. Pin inclination angles at θ = 120o, 135o and 150o could greatly reduce the pressure drop and enhance the thermal performance factor. The greater number of rows in the test section has been proven crucial for some inclination angles in promoting heat transfer performance.