Project Title:

Bubble Tolerant Cold Plate with Multiple, Flowthrough Pumps

  94-01	09.01	7500

  Bubble Tolerant Cold Plate with Multiple, Flowthrough Pumps

Abstract:

Small diameter capillary pumps are the preferred choice for many 
CPLs because of weight and packaging considerations. However, 
recent tests have shown that small diameter pumps are more 
difficult to start and are more susceptible to deprime failures 
than large diameter pumps. These failures have been attributed 
to the presence of two-phase fluid in the pump's liquid core. 
The problems appear to be more severe in zero g, as evidenced by 
the recent failure of the CAPL flight experiment. 
Dynatherm developed under a previous SBIR Phase I contract a 
novel pump which greatly reduces catastrophic failures that are 
related to bubbles in the pump. It features a flow-through 
liquid channel which is plumbed directly into the CPL's fluid 
reservoir. Although tested only briefly, it demonstrated 
excellent stability, proved to be easily started, and operated 
with little or no subcooling. 
The objective of the proposed program is to extend this 
technology to multiple pump coldplates. Several designs have 
been identified which promise to support uneven loading and 
loadsharing between pumps. The performance of breadboard 
coldplates will be measured over a wide range of parameters. A 
flight demonstration would be conducted during Phase II. 
CPLs are poised to compliment heat pipes as standard heat 
transfer elements in spacecraft thermal management. The 
acceptance of CPLs depends on the availability of reliable 
capillary pumps. If the program is successful this milestone 
will have been achieved and commercial development is likely to 
follow. 

Key Words

DYNATHERM CORPORATION
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