Spray Characterization Using Phase Angle Detection.
Abstract
An innovative method for measuring the particle size and velocity, simultaneously using the Doppler difference frequency and the phase shift of the scattered light was derived, analyzed, and evaluated experimentally. Initially, the theoretical analysis of the dual beam laser light scattering phenomena were performed using simple geometrical optics theory. This approach allowed ready insight of the complex scattering phenomena associated with the method. In particular, the difficulties that may occur when scattering amplitudes due to reflection and refraction are of similar order of magnitude were easily investigated. Numerous experiments using monodispersed drop streams were used to assess the measurements accuracy and possible errors produced by the mixed scattering components. The Lorenz-Mie theory was derived for the dual beam scattering and used to evaluate the measurement capability for particles on the order of a micron in diameter. Experiments were conducted using polytyrene latex spheres to demonstrate that particles as small as 0.5 micron can be measured. Comparisons with sampling probe data, nozzle flowrate, and light extinction measurements were in good agreement. Incorporation of frequency shifting into the system allowed the measurement of the drop angle of trajectory and reversed flow velocity components, while eliminating possible sizing errors produced by reversed flows. Successful measurements have been made of drop size and velocity in turbulent spray flames with swirl and recirculation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 18, 1986
- Accession Number
- ADA173572
Entities
People
- William D. Bachalo