The effect of entrance conditions on an expanding arcjet flow

Flow development with various entrance conditions in a conical arcjet nozzle is simulated for a test gas consisting of nitrogen and argon. Simulations with uniform nozzle entrance conditions are performed and nozzle exit centerline conditions are compared with available experimental data. Simulations with entrance conditions consisting of a hot core and cooler annulus are then performed, and it is found that the non-uniformity persists through the nozzle, affecting the exit centerline temperature and velocity. Pitot pressure and heat transfer profiles determined horn simulated exit conditions are used to evaluate the effectiveness of pitot pressure and calorimeter measurements in determining the extent of flow uniformity. It is found that heat transfer measurements are far superior to pitot pressure measurements in assessing flow uniformity.