The Effect of a Low-Loss Air Valve on Performance of a 22-Inch-Diameter Pulse-Jet Engine

The performance of a 22-inch-diameter pulse-jet engine using a set of low-loss modified air valves was determined in thrust-stand tests at ram pressures equivalent to simulated flight speeds of 0 to 330 miles per hour and for a range of fuel-air ratios at each simulated flight speed. The results of these tests are compared with tests of the standard pulse-jet engine.

In general, the modified engine showed an improvement in performance only at low simulated flight speeds. The predicted flight thrust at high simulated flight speeds was slightly lower than that for the standard engine, and the specific fuel consumption was higher. From the results of these tests, it appears that only a negligible change in the over-all performance of the engine can be expected from low loss valves.