Disk spin-down measurements in the free-molecular flow regime: A new method for measurement of tangential momentum accommodation coefficients

作者：Acharya Tathagata^*; Falgoust Jordan; Rasmussen Richard; Martin Michael J

来源：Vacuum, 2016, 126: 70-79.

DOI：10.1016/j.vacuum.2016.01.012

• Free molecular flow
• Tangential momentum accommodation coefficient
• Gas bearings
• Experimental fluid dynamics

An experimental technique using spin-down of a disk approaching the free-molecular flow limit is developed to measure the tangential momentum accommodation coefficient at. The new technique uses a disk mounted on a shaft supported by gas bearings in vacuum. A differential scavenging system allows disk spin-down experiments in different gases. Representative test results with two different materials in two different gases are shown, demonstrating the method is capable of handling a range of gases, as well as any material that is available as, or can be formed into, a planar disk.

• 出版日期2016-4