Particulate Infiltration into a Simulated Space Telescope
Abstract
To understand the dynamics of airborne particulate intrusion into a space telescope, a mechanistic model based on mass balance was developed to predict the extent to which ambient particles penetrate through vent holes and enter the interiors after the purge is off. This work describes the mathematical modeling analysis, supplementing with results from laboratory measurements using a cylindrical chamber as a simulated space telescope. It was found that the characteristic time for airborne particles to reach a saturation level, after the purge is off, can be characterized by the air-exchange rate and particle deposition rate inside the confined space volume. The air-exchange rate, measured using a tracer gas technique, is associated with the natural convection and air flow turbulence intensity adjacent to the chamber. During the purge outage, the steady-state airborne particle concentration inside the space telescope is governed by the ambient particle concentration, air-exchange rate, and particle deposition rate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 2008
- Accession Number
- ADA505618
Entities
People
- De-ling Liu
- Kenneth T. Luey
Organizations
- The Aerospace Corporation