Patent ID: 6290505
Filing Date: 2001-09-18
Classification: B64G

Abstract:
A method for deriving a simulated thrust-versus-time profile for a specific type of rocket motor operating at a chosen motor temperature, comprising the steps ofA. Test-firing a rocket motor of the specific type at a first motor temperature and measuring values for a first complete thrust-versus-time profile at that first temperature, the profile being defined by a time axis and a thrust axis, wherein total impulse of the motor during the test firing is shown by the area under the thrust-versus-time profile over the entire action (running) time of the motor,B. Test-firing a rocket motor of the specific type at respectively extremely high and extremely low motor temperatures to measure two sets of values for total impulse and total action time for the respective high and low temperatures,C. Interpolating the chosen motor temperature between the high and low extreme motor temperatures to derive interpolated values of total impulse and total action time at the chosen motor temperature, andD. Creating a derived thrust-versus-time profile for the specific rocket motor type at the chosen temperature by multiplying the value on the time axis of the first profile by a factor which compresses or expands the profile as necessary on the time axis to make the total action time used in the derived profile equal to the derived action time and multiplying the value on the thrust axis of the first profile by a value which compresses or expands the profile as necessary on the thrust axis to make the total impulse shown under the curve of the derived profile equal to the derived total impulse,whereby the resulting derived profile which has been compressed and expanded as necessary on those two axes is a good approximation of the profile which would be derived by running and plotting a complete test firing at the chosen motor temperature.