Multiple-Wavelength Transmission Measurements in Rocket Motor Plumes
Abstract
Multiple-wavelength light transmission measurements were used to measure the mean particle size (d32), index of refraction (m) and standard deviation of the small particles in the edge of the plume of a small solid propellant rocket motor. The results have shown that the multiple-wavelength light transmission measurement technique can be used to obtain these variables. The technique was shown to be more sensitive to changes in d32 and standard deviation than to m. A GAP/AP/4.7 % aluminum propellant burned at 25 atm produced particles with d32=0.150+/-0.006 microns, standard deviation =1.50 +/- 0.04 and m = 1.63 +/- 0.13. The good correlation of the data indicated that only submicron particles were present in the edge of the plume. In today's budget conscious industry, the solid propellant rocket motor is an ideal propulsion system due to its low cost and simplicity. The major obstacle for solid rocket motors, however, is their limited specific impulse compared to air breathing motors. One way to help overcome this limitation is to utilize metal fuel additives. Solid propellant rocket motors can achieve high specific impulse with metal fuel additives such as aluminum. Aluminum propellants also increase propellant densities and suppress transverse modes of combustion oscillations by damping the oscillations with the aluminum agglomerates in the combustion chamber. One disadvantage of using metal fuel additives that cause large agglomerates in a rocket motor is a large thrust loss.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1991
- Accession Number
- ADA245999
Entities
People
- Hong-on Kim
Organizations
- Naval Postgraduate School