Flight Performance Prediction of a Solid Fuel Ducted Rocket Engine with Direct-Connect Ground Tests

A methodology based on direct-connect ground tests was developed for flight performance prediction of a solid fuel ducted rocket engine. Deviations in the target simulated state frequently occur in ground tests given testing system errors. To mitigate the influence of deviations on the accuracy of the prediction method, direct-connect vacuum-specific impulse efficiency processed from engine test data is used to predict a flight-specific impulse and other performance parameters. The developed method was applied to a typical ground test of a ducted rocket engine, and the predicted flight specific impulse efficiency was 16% higher than that through the method, regardless of state deviations. On the basis of a series of ground test data, the flight performance prediction of an engine under different air/fuel ratios was conducted, and results showed that the optimum flight performance is achieved near the air/fuel ratio that corresponds to the maximum theoretical flight-specific impulse. With an assumed flight-specific impulse efficiency value of an engine, the flight performance under a full flight envelope was predicted, thereby providing a flight performance reference despite a certain error.