The heat transfer performance and wall temperature variation of copper-water oscillating heat pipe(OHP)and copper-ethanol OHP at different heating powers was experimentally investigated.The results show that

under normal conditions

the temperature difference between evaporation and condensation section of water OHP is smaller than that of the ethanol OHP

and the heat transfer resistance of water OHP is also lower.Comparison of wall temperature fluctuation curves between the two OHPs indicates that

at low heating powers

there are clear shifts in the water OHP's wall temperature

with an increase in heating power;however

there's no such a situation in the ethanol OHP;at high heating powers

the heat transfer resistance of water OHP increases continuously

while inside local parts of the ethanol OHP

overheating occurs in working fluid

but the heat transfer performance maintains stable.Finally

the experiments imply that

the heat pipes with large temperature fluctuation amplitude

high vibration frequency

and stable and uniform fluctuation have better heat transfer performance.