A facility has been constructed to simulate the flow in a pulse detonation engine. This report describes the design, construction, initial test results, and analyses of the basic operation of the facility. The principle of operation is that of a blow down wind tunnel with a pressurized supply reservoir of air emptying through a test section into a low pressure receiver vessel. The flow is started abruptly by rupturing a diaphragm that separates the downstream end of the test section from the

more »

... eiver vessel. Following a short transient period of a wave propagation, a quasi-steady flow is set up in the rectangular test section of 100 x 100 mm cross section. The quasi-steady operation lasts about 0.15 s. During this time, a typical operating condition results in a test section Mach number of about 0.7 and a velocity of 200 m/s. The pressure and temperature in the test section can be adjusted by varying the conditions in the supply reservoir. The current implementation uses room temperature air at pressures up to 6 bar in the supply reservoir. Tests were carried out to determine the performance as a function of the pressures in the supply and receiver vessel. Measurements included pressure and temperature in the two vessels and pitot and static probe measurements of the test section flow. Flow visualization with a schlieren system was also carried out. The data were analyzed by using simple one-dimensional steady and unsteady gas dynamics. Some two-dimensional unsteady numerical simulations were also carried out to examine the influence of the diaphragm location on the flow starting process. A control-volume model has been developed to predict the variation of pressure with time in the supply and receiver vessels. This model and analyses of the tests indicates that choked flow results in a constant Mach number inside the test section. The duration of the choked flow regime and the conditions within the test section can be reliably estimated with this model.