Experimental study on the heat transfer performance of ultra-thin flattened heat pipe with hybrid spiral woven mesh wick structure

In this work, eight different spiral woven mesh (SWM) structures, namely, SA, SB, SC, SD, SE, SF, SG and SH, were designed to investigate the effect of the SWM weaving method on the heat transfer performance of ultra-thin heat pipes (UTHPs). The SA and SH were SWMs, severed as the control group, and they were woven using only 0.05 and 0.04 mm diameter copper wires, respectively. The other six types were hybrid SWM (HSWM) structures that were woven from the two diameters copper wires. The thermal performance of the UTHPs with different SWM/HSWM wick structures was experimentally investigated. The results indicated that the number and distribution of different-diameter copper wires in every strand of HSWM determine the pore size and total pore volume inside the wick. The staggered arrangement of different-diameter copper wires in the HSWM is conducive to the formation of more multisize pores in the wick, thereby improving its comprehensive hydraulic performance. Compared with the SA and SH UTHPs, the maximum heat transport capacity of the SB and SF UTHPs increased by 33.33–53.85% and the total thermal resistance decreased by 27.53–42.92%, significantly improving the heat transfer performance of UTHP by using the appropriate HSWM wicks.