Reconstruction Technique for Reducing Hybrid-Rocket Combustion Test Data

A new integral technique has been developed for the purpose of analyzing combustion test data in hybrid rocket firings. The method, which utilizes a complete reconstruction of the regression history, is shown to have several advantages when compared with the current endpoint technique, in which average regression rate and port mass flux are determined based on fuel grain initial and final dimensions. One significant advantage is that the integral method permits one to ascertain the sensitivity of regression rate to changes in mass flux in a single test. Action (burning) times greater than 5 s have been found to be preferred over shorter values more typically used to date, because this minimizes errors in action time determination and permits the fuel to reach a steady-state thermal profile.