A Study on Performance of a Detonation-Driven Shock Tube

A detonation-driven shock tube firstly designed by H.-R. Yu, is considered as a useful facilities capable of producing high-enthalpy flow. In this apparatus, a strong shock wave is generated by detonating oxygen-hydrogen (oxyhydrogen) mixture and has characteristics that temperature as well as pressure of driver gas is extremely high compared with conventional shock tubes. However, a structure of detonation wave is not uniform e.g., detonation wave has three-dimensional cellular structures and multiple transverse waves. Furthermore, the detonation wave is followed by a Taylor expansion fan and performance of detonation-driven shock tube is not well understood. In this preliminary study, a detonation-driven shock tube is constructed and its performance is experimentally investigated by measuring pressure histories and a profile of ionization current behind detonation wave. As a result, (i) the pressure histories of detonation wave is clarified and it shows reasonable agreement with a result obtained by KASIMIR shock tube simulation code. (ii) A propagation velocity of detonation wave is coincided well with theoretical predictions assuming Chapman-Jouguet detonation wave. (iii) An equivalence ratio of oxyhydrogen mixture to produce a highest Mach number of the shock wave is evaluated as 〓≃1.7