Computer Code to Predict Fluid Flow Stability Of Capillary Pumped Loops 

TTH Research, Inc.

Capitol Heights, MD

Implementation of recent, novel hydrodynamic-theoretical study. Improves reliability of CPL design by predicting incidence of depriming behavior, the main impediment to reliable operation

• Completed mathematical model to perform nonlinear hydrodynamic stability analyses for multiple pump/condenser CPL systems.
  
• Implemented model in simplified computer code.
  

• Computer model, for the first time, predicted unstable CPL flow regimes within which the system failed to operate.
  
• Successfully utilized to analyze hydrodynamic stability characteristics of various CPL systems including Terra Spacecraft’s CPHTS, CAPL-3 and HOST flight experiments.
  
• Incorporated into SINDA thermal analyzer to simulate on-orbit transient behaviors.
  

• Computer code has been in active use at Goddard ever since for evaluating CPLs.
  
• For EOS-Terra, the results of the code analysis indicated that the liquid line size was too small under dynamic conditions even though it was fine for steady state operation. Such a result was experimentally verified in GSFC lab. Because of this finding, the EOS-Terra project was convinced to enlarge the liquid line so as to mitigate the risk.
  
  

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