Effects of non-condensable gas on the performance of oscillating heat pipe, part II: Experimental study

In this paper, we investigate the effects of non-condensable gas (NCG) on the flow characteristics of liquid slugs–vapor plugs and heat transfer performance (λeff) of oscillating heat pipe (OHP), experimentally, in order to validate our simulation results of part I. The experimental results show that NCG decreases the heat transfer performance of OHP, which are the same with our simulation results. From experimental results, NCG increases the time-average temperature of heating section. This means that the liquid slugs enter the heating section less frequent (bubbles generation is also less frequent), then the total amount of evaporation and total amount of heat transfer through working fluid decrease. In the adiabatic section, NCG decreases the fluctuation of wall temperature, which means that the motion of liquid slugs and vapor plugs becomes less active. And in the cooling section, NCG decreases the fluctuation and also time-average of wall temperature, which means that NCG obstacles the condensation. The experimental results also show that the effects of NCG on the heat transfer performance of OHP are smaller than that of the loop heat pipe and conventional heat pipe, which agree and validate our simulation results.