Experimental study on the enhancement of contact heat transfer by micro fin

Abstract A series of experiments was performed to investigate the enhancement effect of micro fin, contact pressure, and interface temperature on thermal contact conductance. The specimens were made of 7075 aluminum alloy. The contact surfaces of specimens with micro fin were specially machined such that two specimens were coaxially inlayed together. Contact pressure ranged from 2 MPa to 4.2 MPa, and interface temperature ranged from 165 °C to 180 °C and 215 °C to 227 °C. Experimental results showed that the micro fin could enhance thermal contact conductance, and the contact heat transfer enhancement effects caused by the micro fin gradually increased with contact pressure. Thermal contact conductance was high under higher interface temperature. The loading process changed the enhancing effect of the micro fin, and enhancement of contact heat transfer was greater in the unloading process than in the loading process. A qualitative analysis on the enhancement effect was conducted to explain the contact heat transfer enhancement effect for different micro-finned surfaces.