Byoung-Jik Lim

Fuel-Side Cold-Flow Test and Pressure Drop Analysis on Technology Demonstration Model of 75 ton-class Regeneratively-Cooled Combustion Chamber

․ Jong-Gyu Kim** ․ Byoungjik Lim* ․ Munki Kim** ․ Donghyuk Kang** ․ Seong-Ku Kim* ․ Hwan-Seok Choi*ABSTRACT Fuel-side cold-flow tests were performed on the technology demonstration model of a 75 ton-class liquid rocket engine combustion chamber for the first stage of the Korea space launch vehicle Ⅱ. Pressure drop in the cooling channels of the combustion chamber was measured by changing fuel mass flow rate through a pressure regulating system. Pressure d rop in each segment of the chamber could be obtained and a lot of pressure drop was caused by high flow velocity in the nozzle throat segment. The accuracy of a hydraulic analysis method for calculating a pressure loss in cooling channels could be verified by applying it to the cold-flow test conditions. 초 록 한국형발사체 1단에 사용될 75톤급 액체로켓엔진 연소기의 기술검증시제를 설계, 제작하여 연료 수류시험을 수행하였다. 가압압력을 조절하여 연료 유량을 변경함으로써 주어진 유량에서 발생하는 연소기 재생냉각 채널에서의 압력 손실을 측정하였다. 연소실 각 부에서의 압력 손실을 측정할 수 있었으며, 상당량의 압력 손실이 유속이 강한 연소실 노즐목부에서 발생함을 확인하였다. 주어진 연료 수류시험 조건에서 수력학 해석을 통하여 수력학 해석 방법의 정확도를 검증할 수 있었다. Key Words: Liquid Rocket Engine(액체로켓엔진), Regeneratively-Cooled Combustion Chamber( 재생냉각 연소기), Fuel-Side Cold-Flow Test(연료 수류시험), Pressure Drop Analysis(차압 해석)

Flow Control Characteristics of Cavitating Venturi in a Liquid Rocket Engine Test Facility

The flow rate control of a cavitating venturi has been investigated with downstream pressure variation. A set of cavitating venturies for a liquid rocket engine thrust chamber firing test facility have been designed and manufactured. The flow characteristics of the cavitating venturies have been analyzed by experimental and computational methods. Results showed that constant mass flow rate condition was established by the cavitation inside the venturi. However, upstream pressure less than the actual design pressure of the cavitating venturi could not supply a constant flow rate.

Thermal Barrier Coating Durability Testing Trends for Thrust Chamber of Liquid-propellant Rocket Engine

․ Chul-Sung Ryu** ․ Byoung-Jik Lim* ․ Hwan-Seok Choi*ABSTRACT Durability testing method trends of the thermal barrier coati ng(TBC) for the combustion chamber of the liquid-propellant rocket engine have been investigated. Many types of the durability testing method such as the mechanical tests to measure surface cohesion force, the thermal fatigue tests with laser, furnace, burner or plasma, the small scale combustion te sts using injectors, and the thermo-mechanical fatigue tests were observed. The TBC with suf ficient durability can be selected for the use of combustion chamber through such specimen-level tests and the durability can be verified by the tests using the real scale combustion chambers.초 록 액체로켓 연소기에 사용되는 열차폐코팅(TBC)의 내구성 시험 기술동향을 조사하였다. 표면 접합력 측정을 위한 기계적 시험, 레이저나 가열로, 버너나 플라즈마 등을 이용한 열피로 시험, 분사기를 이용한 소형 연소시험, 열적 기계적 피로시험 등의 많은 내구성 시험들이 있었다. 연소기에 사용하기 위해 이러한 시편 수준의 시험을 통해 내구성이 확보된 TBC를 결정할 수 있으며, 실제 연소시험을 통해 내구성을 검증할 수 있다.Key Words: Combustion Chamber(연소기), Thermal Barrier Coating(열차폐코팅), Bending Test(굽힘시험), Durability(내구성), Thermal Fatigue(열피로), Combustion Test(연소시험)