Rocket

About: Rocket is a research topic. Over the lifetime, 14018 publications have been published within this topic receiving 95852 citations. The topic is also known as: rockets.

Acoustic Measurement and Prediction of Solid Rockets in Static Firing Tests

Abstract: Acoustic measurements are executed in two series of static-firing tests of a solid rocket motor. The obtained data are quantitatively compared with calculation results of an empirical prediction method, NASA SP-8072 and CFD. According to the results, the NASA SP-8072 overestimates the sound pressure levels at the 20° and 35° points from the jet axis in the far field, although the SPLs at other measured points are reasonably predicted. On the other hand, the CFD calculation can clearly explain the generation and propagation mechanism of the acoustic wave and reasonably predict the SPLs at all the measured points. From the results, it is confirmed that the prediction accuracy of the CFD calculation is within 5 [dB] in overall sound pressure level, which is within the experimental uncertainty involved in the measured data, and the CFD is effective for the prediction of both the near and the far field acoustics generated from the rocket motors.

Interaction of Secondary Injectants and Rocket Exhaust for Thrust Vector Control

Abstract: Tests were conducted with 1300to 1500-lb thrust solid rocket motors in order to investigate the side-force generation mechanisms associated with the injection of a secondary fluid into the expansion cone of a solid propellant rocket nozzle for thrust-vector control. The nozzles were 15° conicals with a nominal expansion ratio of 25:1. All firings were conducted in zero-flow ejectors. Freon-12, water, and gaseous nitrogen were used as the injectant. Nozzle-wall pressure profiles, side thrust , and the nozzle-wall shock interface were recorded. The general character of the pressure disturbance was defined. The major portion of the side force was generated by the pressure disturbance downstream of the injector. The axial-thrust augmentation generated by the injectant was calculated. The effects of nozzle-expansion ratio and injector location on the side force were clearlv illustrated.

Optimum Climbing Technique for a Rocket-Powered Aircraft

Abstract: exit area of the rocket, ft drag coefficient drag coefficient at zero lift drag, lb zero-lift drag, lb aircraft efficiency factor acceleration of gravity, ft sec 2 altitude, ft h + V/2g = energy height, ft lift, lb instantaneous mass of the aircraft, lb ft"" sec mass of propellant consumed per unit time, lb f t 1 sec Mach number atmospheric pressure, lb ft ~ static pressure in the exit section of the nozzle, lb f t 2 local static pressure at a point of the external walls of the aircraft, lb ft ~ air constant, ft sec"" °R~ Reynolds' number wing surface, ft time, sec thrust, lb absolute velocity of the aircraft, ft sec 1 weight of the aircraft, lb average value of the axial component of the relative velocity of the gases in the exit section of the rocket; i.e., velocity referred to a reference frame rigidly connected to the solid part of the aircraft, ft s ec 1 weight of fuel consumed per unit time for an aircraft equipped with air-breathing engines, lb s ec 1 derivative of the air temperature with respect to altitude, ^ f l r 1 ratio of specific heat at constant pressure to specific heat at constant volume = 1.4 for air specific energy, ft sec ~ inclination of the flight path with respect to a horizontal plane (positive for climbing flight) aspect ratio air density, lb sec f t 4