Characteristics of Free-Piston Shock Tunnel HIEST : 1st Report, Tuned Operation of Free-Piston Driver

• Published in: Transactions of the Japan Society of Mechanical Engineers Series B Vol. 68; no. 675; pp. 2968 - 2975
• Main Authors: TAKAHASHI, Masahiro, UEDA, Shuichi, ITOH, Katsuhiro, TANNO, Hideyuki, SATO, Kazuo, KOMURO, Tomoyuki
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Mechanical Engineers 25.11.2002
• Subjects: Tuned Operation
• ISSN: 0387-5016; 1884-8346
• DOI: 10.1299/kikaib.68.2968

A free-piston shock tunnel is the most capable facility to reproduce hypervelocity flows with chemical nonequilibrium around reentry vehicles. However, performance expected for the free-piston shock tunnel has not been achieved yet, mainly due to the lack of driver-gas volume after free-piston compression, which causes decay of shock wave strength and reduction in test time. In order to overcome this problem, the authors proposed the tuned operation method which enables safe overdriving of piston to maintain driver-gas pressure, and ensured its applicability by the tests in the middle-size pilot facility. Then, based on the tuned operation theory the largest free-piston shock tunnel HIEST was designed and built in the National Aerospace Laboratory. In the present study, the tuned operation of the HIEST was attempted and the effect on the performance of the free-piston driver was discussed.