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.

中文翻译：

---

脉冲爆轰水力冲压发动机：模拟和实验

一种新型水运发动机——脉冲爆震水力冲压发动机（PDH）——已经设计、制造和测试。PDH 是一个脉冲爆震管 (DT)，插入一个开口的导水管中。推力由来自导水喷嘴的周期性激波引起的脉冲水射流产生。数值模拟表明，无阀和有阀 PDH 模型可以产生比冲在 600 到 2400 s 范围内的推力。具有 2 升 DT 的各种设计的 PDH 模型在专门设计的试验台上进行了测试，该试验台以最高 10 m/s 的速度以水下射流的形式提供接近的水流。当不考虑第一个操作周期时，无阀和有阀 PDH 模型的测量平均比冲在 350-400 秒的水平。