The present study deals with the development of a single-stage implosion-driven hypervelocity launcher. A thin-walled tube filled with helium surrounded by explosives acts as a driver for the launcher. Implosion of the tube drives a strong shock that reflects back and forth between the projectile and the implosion pinch, generating very high temperatures and pressures. Simple analytic models were used to approximate the performance of the pump tube and its use as a driver for a launcher. Experiments to evaluate the implosion dynamics and performance of the pump tube were carried out, and implosion-driven launcher experiments demonstrated muzzle velocities above 4 km/s with 5-mm-diameter aluminum projectiles. Projectile integrity was verified by high-speed photography. Disagreement of experimental data with the analytical models of performance is mostly due to failure to seal the chamber of the launcher, resulting in loss of driver gas, and pump tube expansion, which weakens the precursor shock.

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The design, development, construction, and instrumentation features of a supersonic shock tunnel that produced high temperature supersonic flow for a short duration, on the order of 2 msec, are presented. The shock tunnel was equipped with a Mach 3 supersonic 2-D nozzle. Test runs were conducted using air and helium drivers at driving pressures varying from 200-450 psig (1.4-3.1 MPa gage), with the driven gas in all the cases being ambient air. Pressure and temperature measurements were made to document the operating conditions of the tunnel. Total pressure measurements were made in the settling chamber of the nozzle where the flow Mach number is 0.14 (weakly subsonic). Static pressure measurements were made at the exit of the nozzle to establish the unsteady starting process of the nozzle. Total temperature measurements using thermocouples were made in the settling chamber of the nozzle to identify the maximum temperature attained in the flow. Surface heat flux measurements were made at the exit of the nozzle and compared with previous skin friction measurements. The measured pressures and temperatures compared well with the predicted values for the air driver. In the case of the test runs with the helium driver the nozzle started, but the flow was unsteady. Consequently, there were difficulties in making measurements and interpreting them. The surface heat flux and skin friction followed the Reynold's analogy within 50% during the steady run time of the shock tunnel. / M.S.