Particle Sampling with Supersonic Probes. Similitude and Particle Breakup
Abstract
The problems encountered in sampling the exhaust flow from a solid propellant rocket motor being tested at simulated altitude are examined. Characteristics of the flow field, shock detachment, and particle trajectories are discussed for a cylindrical, supersonic particle probe. The form of the scaling law for probe collection efficiency is suggested for both Stokesian and non-Stokesian particles from the normalized equation of particle motion and simple expressions for the particle drag coefficient. Conditions for the onset of particle breakup in normal shock waves were investigated. A normalized particle drag behind the shock was determined in terms of gas stagnation conditions and particle diameter for a range of gas Mach numbers between 1 and 5 by including appropriately defined particle Knudsen and Reynolds numbers in analytical expressions for the drag coefficient. Numerical computations of the particle drat, normalized with gas stagnation pressure and particle area, indicate a peak at a gas Mach number of about 2.2. The magnitude of the peak was found to decrease with increasing particle diameter and reservoir gas density.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1983
- Accession Number
- ADB076165
Entities
People
- L. J. Forney
- P. T. Girata Jr.
- W. K. Mcgregor
Organizations
- Arnold Engineering Development Complex