Numerical investigation of flow instability in shock tube due to shock wave-contact surface interactions

摘要

Purpose - The purpose of this paper is to perform a computational fluid dynamics (CFD) simulation that is able to reveal what is happening for the shock wave generated by high speed flow test facility and to develop deeper understanding of all parameters which affect the shock wave velocity profile and pressure and temperature histories inside the facility. Design/methodology/approach - Two dimensional time accurate Euler solver for shock tube applications was developed to simulate the flow process inside the shock tube. To ensure the ability of the CFD code to capture shocks, rarefaction waves and contact discontinuity and to produce the correct pressure, temperature, density and speed profiles, the code has been validated using two verification approaches. First, the code results have been compared to the Sod's tube problem (exact solution). Second, the code solution is compared with selected experimental measurements for a certain diaphragm pressure ratio. Findings - Results presented in this paper show that after diaphragm rapture and when the shock did not reflect yet, the flow is symmetry and uniform in y-direction. As the shock wave reflects from the tube end it will move to the left and interact with the discontinuity surface and the flow no longer symmetry. Results also show that two-dimensional modeling of the high speed flow test facility is an effective way to obtain facility performance data. Although this paper focused on UNITEN's facility, the CFD code is generic and may be applied to other facilities. The present code showed good capability to provide the x-t diagram successfully. From this diagram one can determine the useful duration (for this case it is about 10 ms), which is quite comparable compared to other facilities. It can be concluded, based on the agreement with the analytical results, that the numerical formulation for the inviscid part of the solver is valid. Originality/value - This paper performs a CFD simulation that is able to reveal the shock wave behavior at high speed flow test facility.