A FEEDBACK CONTROLLED GAS MIXING SYSTEM FOR THE RAM ACCELERATOR

M. R. Jardin* and A. P. Bruckner+
Aerospace and Energetics Research Program
University of Washington, FL-10
Seattle, Washington 98195



Abstract

A feedback-controlled gas mixing system is presented along with operational
results for a prototype implementation, which has been developed for the
University of Washington ram accelerator hypervelocity launcher facility. The
control system is designed to fill high-pressure chambers with a selected
number of component gases (four for the ram accelerator) at a chosen set
of molar ratios. A mass-flow-rate controller keeps the mass-flow rate of a
primary gas constant while secondary gas controllers drive the molar-ratio
errors to zero, thereby ensuring that the final gas composition is correct.
The sensing elements are resistive thermal detection (RTD) mass-flow meters,
and the control elements are switched servo-actuated metering valves.
Experimental results for the operation of the prototype system are reported.

-------------------------------------------------
*Aerospace Engineer.; Air Traffic Management Branch,
NASA Ames Research Center, MS 210-9,
Moffett Field, CA 94035.

+Professor of Aeronautics & Astronautics.

===============================================================================
For a full copy of this report, contact:

American Institute of Aeronautics and Astronautics
370 L'Enfant Promenade, S.W.,
Washington, DC  20024