Numerical Simulation of a Ludwieg-tube Fuel Delivery System for Scramjet Experiments in Shock Tunnels

The T4 shock tunnel at The University of Queensland is regularly used to perform supersonic combustion experiments. The fuel for the test model is supplied using a Ludwieg-tube delivery system. A combination of theoretical modelling and calibration tests is used to determine the mass flow-rate of fuel for given Ludwiegtube initials conditions and the measured pressure in the plenum chamber that supplies the fuel to the model. The theoretical model used in the calibration procedure is presented. The goal of this project is to check the suitability of the modelling assumptions by simulating the complete Ludwieg-tube system using the one-dimensional Lagrangian computer code, L1d. Simulation of the fuel delivery system is done separately for viscous and inviscid flow with conditions replicating those used in supersonic combustion tests in T4. The steady plenum pressures from the simulations of inviscid and viscous flow are, on average, within ±7% and ±4%, respectively, of the values measured experimentally. Further, the fuel mass flow-rates obtained from viscous simulations are, on average, within ±13% of the experimental values.