액체질소를 이용한 산화제펌프의 극저온 성능시험

Abstract

초록: 액체질소를작동유체로한극저온시험설비를이용하여산화제펌프의성능시험을수행하였다. 설계회전수의30~55%영역에서시험을수행하였으며, 그결과를작동유체로물을이용한상온수류시험의결과와비교/분석하였다. 수력성능에있어서는회전수에대한상사성을만족시킴으로써, 설계회전수인20000rpm에서의성능예측을가능하게했다. 펌프의극저온흡입성능에서는설계유량에서극저온임계캐비테이션수가0.012으로나타났으며, 상온수류시험의경우는0.024를보이면서, 모든시험회전수와시험유량영역에서수류시험의경우보다향상된결과를보였다. 이러한향상된극저온환경에서의흡입성능은극저온유체에서펌프의열역학적인효과로부터기인하는것으로판단된다.Abstract: Performance tests of a liquid-oxygen pump were carried out using liquid nitrogen (LN2) as a working fluidin a cryogenic turbopump test facility in Korea Aerospace Research Institute (KARI). The tests were performed at30-55% of the design rotational speed, and the results were compared with those from a water test. The experimentalresults confirmed the similarity of the hydraulic performance, which allows the prediction of the pump performance ata design rotational speed of 20,000 rpm. The overall cavitation performance of the pump in the cryogenic environmentwas better than that in the water environment for all ranges of flow rates and rotational speeds. Critical cavitationnumber at the design flow rate was determined as 0.012 from the cryogenic test, and as 0.024 from the water test.The improved cavitation performance is due to the thermodynamic effect in cryogenic fluids.