Control Panel is a computer program that generates a graphical user interface (GUI) for computational simulation of a rocket- test-stand propellant mixer in which gaseous hydrogen (GH2) is injected into flowing liquid hydrogen (LH2) to obtain a combined flow having desired thermodynamic properties.

The GUI is used in conjunction with software that models the mixer as a system having three inputs (the positions of the GH2 and LH2 inlet valves and an outlet valve) and three outputs (the pressure inside the mixer and the outlet flow temperature and flow rate). The user can specify valve characteristics and thermodynamic properties of the input fluids via user-friendly dialog boxes. The user can enter temporally varying input values or temporally varying desired output values. The GUI provides (1) a set-point calculator function for determining fixed valve positions that yield desired output values and (2) simulation functions that predict the response of the mixer to variations in the properties of the LH2 and GH2 and manual- or feedback-control variations in valve positions. The GUI enables scheduling of a sequence of operations that includes switching from manual to feedback control when a certain event occurs.

This program was written by Fernando Figueroa of Stennis Space Center, Hanz Richter of the National Research Council, and Enrique Barbieri and Jamie Granger Austin of Tulane University. Inquiries concerning rights for the commercial use of this invention should be addressed to

the Intellectual Property Manager, Stennis Space Center, (228) 688-1929.

Refer to SSC-00213.

NASA Tech Briefs Magazine

This article first appeared in the November, 2005 issue of NASA Tech Briefs Magazine.

Read more articles from the archives here.