Detonation Tube

  Schematic skecth of the detonation tube Copyright: © HGD

The short-duration rocket nozzle flow simulation facility is based on the detonation-tube technique. It consists mainly of 4 sections, a damping section of 3 m, a detonation tube of 10 m length with an attached axisymmetric nozzle and a vacuum tank. The inner diameter of the tube sections amounts to 60 mm. The damping section to the detonation tube as well as the detonation tube to the nozzle are separated with diaphragms before flow initiating.

The detonation tube is filled with oxyhydrogen. After ignition with a 1.3 kV electric spark, a detonation wave occurs and delivers a high enthalpy flow for the rocket nozzle. The relatively large vacuum tank delivers a low pressure at the nozzle exit and thus guarantees a supersonic nozzle flow during the measurement time. The damping section reduces the thermal and mechanical loads of the incoming detonation wave at the end wall as well as enlarges the testing time. The flow medium is a premixed hydrogen-oxygen explosive gas. The facility generates stagnation pressures up to 150 bar and stagnation temperatures up to 3800 K for a testing time up to 10 ms, which is used to investigate cooling techniques for rocket nozzles.