Fatigue life evaluation of a closed-loop oscillating heat-pipe with check valves (CLOHP/CV) at operated temperature

Abstract

This study evaluates the fatigue life of a closed-loop oscillating heat-pipe with check valves (CLOHP/CV). The method was predicting the fatigue life of the copper tube to apply for the CLOHP/CV. The fatigue test was carried out by using the specimens made of copper tube (C1220) at the temperature of 293 (room temperature), 473 and 573 K. The three types of hourglass shaped specimen included uniform type, one-wave type and two-wave type specimens. It was found that the effect was a direct extension of material structures of specimen and hourglass shaped. It can be said that the number of cycles to failure (Nf) of the two-wave type specimen, hourglass shaped specimen was rather sensitive to fatigue motion during testing, and the temperature of 573 K has the greatest failure impact.