Experimental investigation of heat transfer in the trapezoidal channel with lateral outflow under rotation conditions

The heat transfer characteristics of wedge-shaped transverse outflow channels with different pin-fins under rotating conditions were measured experimentally. The Reynolds number varies from 10,000 to 70,000, and the rotation number varies from 0 to 0.6. For non-rotating state, the Nussel number decrease along the flow direction on the pin-fin rough surface as inner smooth area, albeit marginally. For rotating state, the enhancement of Nusselt number ratio in the outer pin-fins area is significantly weaker than inner smooth area. The heat transfer of the leading and trailing surfaces shows an increasing trend with the ascend of the rotation number. At the same time, due to the Coriolis force, the heat transfer of the trailing surface is stronger than that of the leading surface. Results show that the total heat transfer of the four experimental models intensify with the increase of the total cross-sectional area of the pin-fins. In particular, the total cross-sectional area of pin fin is increased by 3 times, and the heat transfer of channel can be strengthened by 46-77%. The effective method to increase the total cross-sectional areas of the pin fins is to increase their diameters.