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Development of a Large Bore Valve with a 1 millisecond Opening Time

Shock Tubes are routinely used to generate shock waves in laboratory environments. A shock tube consists of a long pipe with a high pressure section initially separated from a low pressure section by means of a thin diaphragm. The diaphragm is burst, resulting in a pressure wave propagating from the high pressure section into the low pressure section. The pressure wave steepens up into a shock wave after a few diameters. The use of diaphragms has two disadvantages. Firstly they need to be replaced for each test which is time consuming, and secondly they do not allow the shock formation process to be controlled. The particular project required the generation of shock waves and pressure waves.

In order to overcome these disadvantages, a very simple rapidly opening valve was developed. The valve had a rapid turnaround time allowing tests to be conducted at a high rate. The valve opening time could also be increased, allowing the formation of pressure waves at the test section. The simplicity of the valve resulted in very reliable operation.