Numerical simulation of high-enthalpy experiments in the LENS-X expansion tube facility

High-enthalpy hypersonic experiments performed at the Large Energy National Shock (LENS) expansion tube facility are investigated using computational fluid dynamics. The objective of this work is to provide characterization of the experiments in terms of free-stream composition and test-time, and to provide a framework for the design of future experiments to be performed in this facility. The flows in the expansion tube and the nozzle leading to the test-section are simulated. Agreement between measurements and calculations is good for the pitot pressure at the end of the tube. The simulations show that a test-time of three milli-seconds can be achieved for this set of initial conditions, and the free-stream at the test-section of the experiment is not reacted. The flow over the doublecone at these free-stream conditions may be unstable.