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Multiple-wavelength light transmission measurements were used to measure the mean particle size (d32), index of refraction (m) and standard deviation (o) 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 (o) than to m. A GAP/AP/4.7 % aluminum propellant burned at 25 atm produced particles with d32 = 0.150 ± 0.006 n, o = 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., http://archive.org/details/multiplewaveleng1094526645, Major, Korean Air Force, Approved for public release; distribution is unlimited.

An experimental investigation was conducted to measure soot properties and concentration, and infrared signature of the plume of a kerosene/gaseous oxygen rocket motor. Multiple-wavelength measurements were used to obtain soot parameters. It was found that the multiple-wavelength technique appeared to work well for obtaining soot properties and concentration. The results implied that the soot particulate was very porous for the most fuel-rich conditions and became more compact as the 0/F ratio increased, http://archive.org/details/sootparticlesize109458982, Major, Brazil Air Force, Approved for public release; distribution is unlimited.

Transmission measurements using six wavelengths were made through the edges of plumes for solid propellant rocket motors using various propellants and motor geometries. The average values obtained for the aluminum oxide particles were a Sauter mean diameter of 0.30 + /- .02 microns, an index of refraction of 1.64 + /- .04 and standard deviation of 1.52 + /- .12 for the assumed monomodal, log-normal size distribution. The results indicated that the small aluminum oxide particles in the plume edge were gamma-AL203, independent of propellant composition, motor operating conditions and nozzle geometry. The good correlation of the data indicated that the small particles can be adequately represented by a monomodal, log-normal distribution, http://archive.org/details/measurementofsub1094538513, Captain, United States Army, Approved for public release; distribution is unlimited.

Microscopic particles within an optical hologram reconstruction have been successfully measured using an image digitizer and a PC/AT computer. The hologram was recorded during a test burn of some solid rocket fuel and captured a 2 in x 2 in volume of burning particles as they lift from the fuel surface during combustion. The computer processes the digitized images using feature identification algorithms and sizing in the feature's horizontal dimension, its vertical dimension and area. The operation of the algorithms have been validated against calibration objects. Statistical tests show that about 1,300 particles from several image frames are required to obtain a representative size distribution. Overlying speckle degrades the resolution of the image and can be reduced by a variety of techniques. The performance of these speckle-reduction techniques has been measured and compared in the areas of speckle reduction, loss of resolution, and processing time. Program sizes and processing times have been compared for both FORTRAN and C language versions of the processing program, Air Force Astronautics Laboratory, Edwards AFB, CA, http://archive.org/details/automaticparticl00powe, MIPR #: F04611-90-X-0057, NA, Approved for public release; distribution is unlimited.

The particle size distribution inside the combustion chamber and the changes that occurred across the exhaust nozzle were measured in a subscale solid propellant rocket motor with a 2% aluminized end-burning propellant grain and a highly underexpanded nozzle. A combination of diagnostic techniques were used. Size distributions in the exhaust plume were determined by a Single Particle Counter, a Malvern 2600 ensemble particle sizer, and by Scanning Electron Microscope (SEM) examinations of particles collected on a timed exposure impact probe. Size distributions inside the combustion chamber were determined by Malvern 2600 measurements through windows at the nozzle entrance, SEM examinations of particles collected from the nozzle entrance wall, and exhaust plume measurements of a helium quenched motor. It was determined that agglomeration processes dominated in the flow from the center of the combustion chamber up to the nozzle entrance. Particle breakup processes dominated particle behavior from the nozzle entrance, through the nozzle, and into the exhaust., Air Force Phillips Laboratory F04611-92-X-0327, http://archive.org/details/particlebehavior1094524002, Air Force Phillips Laboratory F04611-92-X-0327, Lieutenant, United States Navy, Approved for public release; distribution is unlimited.

Particle size distribution measurements were made with a Malvern 2600c forward laser light diffraction system across the exhaust nozzle entrance and exhaust plume of a small two-dimensional rocket motor. The solid propellants tested were GAP propellants containing 2.0% and 4.69% aluminum. Surface agglomeration of the aluminum, indicated by the in-motor results, was found to decrease as the motor chamber pressures were increased. At low pressures, increasing the aluminum loading with fixed total solids decreased the mean particle size at the nozzle entrance. Exhaust plume particle size was practically independent of nozzle inlet particle diameters, supporting the critical Weber number particle breakup theory. Initial validation of the Malvern 2600c measurements was accomplished by favorable comparison to exhaust plume particle distribution results obtained using a particle collection probe., Air Force Astronautics Laboratory F04611-88-X0021, http://archive.org/details/particlesizingin1094526153, Air Force Astronautics Laboratory F04611-88-X0021, Lieutenant Commander, United States Navy, Approved for public release; distribution is unlimited.

A multiple-wavelength light transmittance measurement system previously used in a laboratory environment to study particles in solid rocket propellant exhaust plumes was modified for use in the field, where high levels of vibration can degrade the accuracy of data. The system was converted from a single light beam configuration to a dual beam configuration which was capable of obtaining a complete set of 1024 reference and scene measurements in 10.0 ms. Modifications included designing, building and testing a new analog-to-digital data converter trigger circuit, and a rotating-wheel light chopper. Optical components including beam splitters, lenses, and a fiber optic cable were installed, and existing data collection system software was modified. The new system was tested by measuring soot from an oxyacetylene torch to prove the design concept. Test results and system performance were documented. Recommendations for further modifications, improvements and applications are presented., http://archive.org/details/dualbeammultiple1094539851, Lieutenant Commander, United States Navy, Approved for public release; distribution is unlimited.

Laser diffraction particle sizing was conducted at the nozzle entrance, inside the nozzle, and in the exhaust plume of a small two-dimensional rocket motor using two different metallized propellants to determine the effects of nozzle geometry on particle breakup. Six different nozzles were used, including three converging nozzles and three converging/diverging nozzles. An AP-GAP/AI propellant containing 4.69 percent aluminum showed no significant effects of nozzle geometry on exhaust plume particle size. Exhaust plume measurements showed consistent results under various conditions, indicating that the particle breakup had been completed at the nozzle throat. The particle size distribution was successfully tracked through the motor for one particular converging section, with particle breakup inside the nozzle occurring prior to that predicted by theoretical analysis. An AP/HTPB/ZrC propellant containing 1/0 percent zirconium carbide exhibited particle size variation in the exhaust plume, but sparse data and varying combustion chamber pressures precluded isolation of the causal factor. Additionally, combustion chamber pressure was shown to decrease measured particle size inside the motor for both propellants. Extensive particle sizing validation experiments using particles of known size suspended in distilled water were conducted throughout the course of the investigation to assist interpretation of laser diffraction particle sizing data., http://archive.org/details/theeffectsofnozz1094525882, Lieutenant, United States Navy, Approved for public release; distribution is unlimited.

Accurate measurement of particle size distribution of rocket motor exhaust is essential for predicting the combustion efficiency and infrared plume signature. This thesis presents an automated method for extracting particle size distribution from scanning electron microscope (SEM) images. The SEM images were taken off a filter paper placed the end of a collection probe inserted into the exhaust plume. The automated SEM extraction system consists of an IBM AT-based computer system fitted with a 512 x 480 pixel frame grabber. Photographic images taken off the SEM are acquired via a vidicon camera. A C language program was written to control the hardware and automate the extraction process. A threshold is first applied to the digitized image and the resulting binary image is subjected to object segmentation. Each object is then sized and the distribution from one or more images can be plotted. The main bulk of this thesis is to document the software specially written to undertake this set of tasks. Results obtained were compared with that from a Malvern MasterSizer particle sizer and found to be favorable. Particles as small as 1/8 um have been successfully sized., http://archive.org/details/particlesizingsy1094528440, Civilian, Singapore Ministry of Defense, Approved for public release; distribution is unlimited.

An experimental investigation was conducted to determine the feasibility of measuring the change in particle size across the exhaust nozzle of a small solid propellant rocket motor. Light scattering measurements were made at small forward angles at the entrance and exit of the exhaust nozzle. The experimental technique was found to be practical, especially if used in conjunction with measurements of transmitted light of multiple wave lengths. However, the determination of D(32) is difficult in the motor environment and is biased toward the larger particles in the size distribution. Particle size measurements were in reasonable agreement with sizes determined from collected exhaust products. Recommendations for further improvement of the apparatus are made., http://archive.org/details/particlesizingin1094521483, Major, Indonesian Air Force, Approved for public release; distribution is unlimited.