Pulsed detonation hydroramjet: simulations and experiments

Abstract

A water transportation engine of a new type—a pulsed detonation hydroramjet (PDH)—has been designed, manufactured, and tested. The PDH is a pulsed detonation tube (DT) inserted in an open-ended water guide. The thrust is developed by shock-induced pulsed water jets periodically emanating from the water guide nozzle. Numerical simulations indicate that valveless and valved PDH models can produce thrust with the specific impulse on the level ranging from 600 to 2400 s. Test firings of PDH models of various designs with a 2-liter DT were carried out on a specially designed test rig, which provides the approaching water flow in the form of a submerged jet at a speed of up to 10 m/s. The measured average specific impulse of valveless and valved PDH models was on the level of 350–400 s when the first operation cycle was not considered. The measured values of the average thrust and specific impulse in the first operation cycle were shown to be always much higher than those in the subsequent cycles: In the tests, the average value of thrust in the first cycle varied from 300 to 480 N, and the value of the specific impulse varied from 960 to 2690 s, which indicates the potential of increasing the thrust performance.