METHOD FOR GENERATING HIGH-SPEED FLOW IN SHOCK WIND TUNNEL AND METHOD FOR BREAKING DIAPHRAGM OF THIS WIND TUNNEL

摘要

PROBLEM TO BE SOLVED: To make longer the duration of a high-speed flow which is generated by breaking the diaphragm of a shock tube. ;SOLUTION: A high-pressure chamber added type shock tube in which a high- pressure chamber 14 filled with helium as a driving gas, an intermediate-pressure chamber 15 filled with an inert gas, and a low-pressure chamber 16 filled with a gas to be tested are formed by partitioning the inside of a tube 11 by first and second diaphragms 12 and 13 is used as a shock tube. Explosives which explode when the explosives are irradiated with a laser beam are fixed to the diaphragms 12 and 13 in cross-like states with a bond, etc. At the time of testing the gas, the first diaphragm 12 separating the intermediate-and low-pressure chambers from each other is broken by exploding the explosive fixed to the diaphragm 12 with the laser beam and the second diaphragm 13 separating the high-and intermediate-pressure chambers from each other is then broken before the expansion wave generated when the diaphragm 12 is broken reach the diaphragm 13. Then the incident shock wave catching up time of a reflected expansion wave is delayed or the reflected expansion wave is extinguished by generating a compressive wave which offsets the expansion wave so that the compression wave can interfere with the expansion wave.;COPYRIGHT: (C)1997,JPO