| This work models mass addition in supersonic diffusers and examines the potential of the mass addition process as a means of altitude simulation in rocket test stands. A computer model of a supersonic diffuser with mass addition has been developed using the influence coefficient method. This model was used to predict the behavior of a supersonic diffuser with mass addition. The model employed an engine with characteristics similar to the Space Shuttle Main Engine. The injection velocity ratio, y, was defined as the ratio of the streamwise component of the injection velocity to the mainstream velocity. The analysis shows that a range of y values between 1.035 and 1.177 yields results conducive to altitude simulation. Mass addition of 25 percent produces a 6.8 percent increase in simulated altitude. Due to physical restraints, the mass addition process was found to be an unattractive tool for altitude simulation of rocket engines. |
