Micronozzles have recently been used for micro-/nanosatellites to expand their role in space development. At low Reynolds numbers, there are inevitable degradations in nozzle performance because of the viscosity. Several studies have revealed and evaluated this phenomenon. Especially at Reynolds numbers under 1000, background pressure significantly affects nozzle performance even in underexpanded conditions, but few studies have investigated the effect of background pressure on nozzle performance by widely changing Reynolds numbers. In this study, we measured the pressure around the nozzle and the thrust while changing the background pressure from 0.007 to 4.1 Pa and the Reynolds number from 33 to 763. The discharge coefficient and the specific impulse efficiency were evaluated, and their correlation to the background pressure and the Reynolds number was obtained. The resulting pressure and nozzle performance suggested that the depletion of gas just after the nozzle exit is the main cause of the performance degradation of the micronozzle.
Background Pressure Effect on Thrust Efficiency of Low-Reynolds-Number Nozzles
Journal of Propulsion and Power ; 38 , 6 ; 1042-1050
2022-06-07
9 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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