국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Durability Tests of OMS Subscale Engine for H-II Orbitinh Plane
저자	Yukio KURODA, Makoto TADANO, Masahiro SATO, Kazuo KUSAKA, Akio MORO, Yoshio AOKI, Yoichiro MIKI
Keyword	ZrO2/Ni chamber; FGM; Reusaable rocket engine; Durability tests
URL	http://send.nal.go.jp/send/jpn/dlfile.php3/naltr01294?doctype=7&filetype=20&path0=naltr01294&path1=pdf&path2=naltr01294.pdf
보고서번호	NAL TR-1294
발행년도	1996.6
출처	NAL (National Aerospace Laboratory of Japan)
ABSTRACT	The reusable regeneratively cooled thrust engine,powered by nitrogen tetroxide(NTO)/monomethyl hydrazine(MMH) propellant,is a candidate for the Japanese orbital maneuvering system(OMS) engine.To improve engine performance,the current generation of this kind of reusable rocket engine is designed to operate with a minimum amount of cooling.Its high performance thrust chamber,however,coupled with extended reuse requirements imposes difficult cooling requirements,particularly in the throat region.To meet the cooling and life enhancement requirements,the inner wall of the thrust chamber incorporates a thermal barrie,such as a ceramic coating to reduce the large wall temperature difference.Such ceramic coatings on teh wall of rocket thrust chambers have been employed for many years.However,the main drawback to the use of these ceramic coatings are the delamination between the ceramic side on teh hot-gas wall and metal side on the cooling wall,and spalling or eventually flake-off during repeated thermal heat load in the combustion test.This is due to the large difference in the thermal coefficient of expansion between the ceramic coating and metal wall,and also to the low ductility of the ceramic coating.One promising method of improving adhesion of the ceramic coating to the metal wall in the thrust chamber is to apply functionally graded materials(FGM) composed of ZrO2 and nickel which can withstand the lower thermal expansion of the ZrO2 thermal barrier coating and which is characterized by high thermal conductivity.For the past 5 years,we have examined the thermal fatigue properties of FGM specimens with a diameter of 30 mm by exposing them to the combustion gases of NTO/MMH propellant.The results of the heat cycle tests revealed improvement of ceramic-metal bonding.The FMG chamber employed in these tests consists of both ZrO2 and Ni components with sequential variation of characteristics from one side composed of ZrO2 to the other side composed of nickel.In this study,durability tests of a regeneratively cooled 1200 N thrust engine composed of ZrO2/Ni FGM were conducted with NTO/MMH propellant.The film cooling fraction was reduced to zero percent of the total fuel flow rate to obtain high performance.A total fo 260 firing tests were performed to evaluate the performance of the engine and to obtain thermal data,and also to inspect the thermal barrier coatings after the cycle of tests in this series.