Vacuum Sealing with a Spiral Grooved Gas Dynamic Seal : Experimental Performance and New Sealing Coefficient for the Extremely Low Pressure Range

抄録

Sealing performance of gas dynamic seals with rectangular spiral grooves is studied experimentally for the purpose of comparison with the theory previously reported by Sawada. Systematic experiments are made for several seals with various geometries over a wide pressure range from the free molecule to slip flow regimes. A new sealing coefficient for the extremely low pressure range which is based on pressure ratio is proposed and is calculated under the condition of a free molecule flow. Suggestions are made regarding the optimum configurations for the rarefied gas dynamic seal.