Heat Conduction Experiments in Rarefied Gases between Concentric Cylinders

Abstract

Experiments were performed to measure heat conduction through rarefied gases at rest contained between two concentric cylinders. The test gases used were helium, neon, and argon. The pressure was varied over a range that included free molecule, transition, and temperature jump conditions. The experimentally obtained heat conduction data were used to evaluate the results of the moment method proposed by Lees and Liu. Agreement between this method and the data was found to be within ±2.5% over the entire Knudsen number range covered in the experiments (0.02 < Kn < 50), assuming that the thermal accommodation coefficient at the inner cylinder remained constant over this range at its free molecule value. A comparison was also made between the data and the results of the temperature jump approximation, indicating that the heat conduction can be calculated by the temperature jump approximation within about 1% at Knudsen numbers less than ∼0.02.