Investigation of flow in the chamber and channel of a variable-area shock tube

One of the factors influencing the uniformity of flow in a shock tube is the noninstantaneousness of diaphragm opening. Using the Lax-Wendroff method, the flow is calculated in a two-dimensional arrangement for a shock tube having a variable cross section and noninstantaneous diaphragm openings. The two-step technique is based on the difference approximation of Euler equations of motion in a divergent form. The difference between the rarefactional wave propagating in a high-pressure chamber and the centered wave is found. Experimental and theoretical results are compared and it is suggested that the technique is applicable to nonstationary problems of gas dynamics.