Project Title:

Transient Computer Code for Two-Phase Systems in Microgravity

Creare Incorporated
P.O. Box 71
Hanover, NH 03755

93-115.02   3800    __      AMOUNT REQUESTED $69,926

Transient Computer Code for Two-Phase Systems in Microgravity

Abstract:

Current two-phase computer codes for modelling of spacecraft
thermal management systems or experiments are inadequate in many
respects. Their multiphase models are inaccurate, outmoded, or
poorly implemented. They are difficult to use without extensive
training, and computation times are measured in days. We propose to
develop an innovative computer code incorporating both modern,
userfriendly interfaces and fundamental mechanistic models for two-
phase flow and heat transfer in microgravity. Using state-of-the-
art concepts in multiphase modelling and in software design, our
objective is to provide a design tool (computer code) that is
compact, fast, and portable, easily used by experimentalists and
designers for transient or steady-state calculations. In Phase I,
a subset of the complete code will be developed and tested for a
condensing radiator model and will also be used to compare with
NASA LeRC flight test data. The final design tool will be the only
existing transient code for spacecraft thermal management systems
which can, by its basic structure, correctly include the twofluid
models for two-phase flow in microgravity from ongoing research at
NASA LeRC. Expected NASA applications include design of two-phase
systems and supporting experiments, and the benefits are greatly
reduced training and computational time for the users.

Commercial applications of an original code for two-phase thermal
and hydraulic behavior would include the effective design,
development, and evaluation of two-phase systems by NASA and its
contractors in support of various major projects: the capillary
pumped loop for the EOS satellites, the mechanically pumped loop
for the space station, and cryogenic fluid management systems for
the Space Transfer Vehicle. Broader applications will be to the Air
Force and its contractors for space-based radar satellites. There
appears to be a need for this tool in the commercial refrigeration
and air conditioning industry, especially to evaluate alternative
fluids to replace CFCs.

multiphase, transient, code