Accession Number : ADA187338

Title :   Diagnostics for Research in Atomization and Turbulent Two-Phase Flows.

Descriptive Note : Annual rept. 31 Jul 86-31 Jul 87,

Corporate Author : AEROMETRICS INC MOUNTAIN VIEW CA

Personal Author(s) : Bachalo, William D

PDF Url : ADA187338

Report Date : 28 Jul 1987

Pagination or Media Count : 17

Abstract : Innovative techniques for obtaining particle size and velocity are being investigated. The four methods are: phase Doppler, ratiometric light scatter detection, Lagrangian frame particle analyzer, and scattered light heterodyne interferometry. Although these methods have overlapping capabilities, each offers additional possibilities for providing heretofore unavailable data. The phase Doppler method has been highly refined and provides reliable particle size and velocity measurements. However, research has been required on the light scattering mechanisms due to nonuniform-light scattering theory and experimental observations have required the expansion of the theory to include the affects of nonuniform illumination. Under certain conditions, the detection of refracted light where none is predicted, remains as a question to be resolved. These questions apply to all of the methods addressed. However, the ratiometric techniques may be used in the on-axis forward scatter light detection mode. This will allow the measurement of irregular-shaped particles moving at high speed using light configuration, the system is limited to dilute particle fields. Currently, the theoretical analysis and optical configuration have been completed and preliminary tests have shown that the basic concept will work. Interests in turbulent dispersion of spray drops suggested the need for measuring the particle dynamics in a Lagrangian frame. The method described promises to provide tracking of individual drops and measuring their local size and velocity. Array detectors are being investigated to provide adequate speed, sensitivity, and spatial resolution. The transmitter optics have been defined.

Descriptors :   *DYNAMICS, *TURBULENT FLOW, *TWO PHASE FLOW, ANALYZERS, ARRAYS, ATOMIZATION, DETECTION, DETECTORS, DILUTION, DISPERSING, DOPPLER SYSTEMS, DROPS, EXPANSION, FRAMES, HETERODYNING, ILLUMINATION, INTERFEROMETRY, LAGRANGIAN FUNCTIONS, LIGHT, LIGHT SCATTERING, MEASUREMENT, NONUNIFORM, OPTICAL PROPERTIES, OPTICS, PARTICLE SIZE, PARTICLES, RELIABILITY, RESOLUTION, SIZES(DIMENSIONS), SPATIAL DISTRIBUTION, SPRAYS, THEORY, TRACKING, TRANSMITTERS, TURBULENCE, VELOCITY

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE