Effects of Non-Condensable Gases on Thermal Performance and Oscillation Behavior of an Oscillating Heat Pipe

Abstract

Non-condensable gas (NCG) significantly affects the thermal performance of oscillating heat pipes (OHPs), but its influence, particularly at higher NCG percentages, remains insufficiently quantified. This study experimentally examines the effects of NCG volume fraction ranging from 0% to 97.8% on the oscillatory behavior and heat transfer performance of an OHP. The results show that even at an NCG volume fraction as high as 97.8%, the OHP still generates stable oscillation motion, and produces an effective thermal conductivity of 2,342.7 W/m·K, which is 5.8 times that of pure copper. As the NCG volume fraction decreases from 97.8% to 0%, the effective thermal conductivity increases from 2,342.7 W/m·K to 4,492.5 W/m·K.