Thin film measurement assessment of the VPCAR water recovery system in partial and microgravity

Nancy Rabel Hall*, Charles Niederhaus, Jeffrey MacKey, Eric Litwiller, Michael Flynn

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

3 Scopus citations


The Vapor Phase Catalytic Ammonia Removal (VPCAR) system is being developed to recycle water for future NASA Exploration Missions [1,2,3,4,5]. Reduced gravity testing of the VPCAR System has been initiated to identify any potential problems with microgravity operation. Two microgravity testing campaigns have been conducted on NASA's C-9B Reduced Gravity Aircraft. These tests focused on the fluid dynamics of the unit's Wiped-Film Rotating Disk (WFRD) evaporator. The experiments used a simplified system to study the process of forming a thin film on a rotating disk. The configuration simulates the application of feed in the VPCAR's WFRD evaporator. The first round of aircraft testing, which was completed in early 2006, indicated that a problem with microgravity operation of the WFRD existed. It was shown that in reduced gravity the VPCAR wiper did not produce a uniform thin film [6]. The film was thicker near the axis of rotation where centrifugal forces are small. A thickening of this film could have a negative effect on the heat transfer coefficient of the evaporator and could result in higher than expected specific power consumption during microgravity operation. In the second round of microgravity tests a potential solution to this problem was tested. This test demonstrated that mounting the feed wiper slightly higher than the axis of rotation of the WFRD disk produced a uniform thin film. This paper presents the results of this reduced gravity testing.

Original languageEnglish (US)
StatePublished - Dec 1 2007
Event37th International Conference on Environmental Systems, ICES 2007 - Chicago, IL, United States
Duration: Jul 9 2007Jul 12 2007


Other37th International Conference on Environmental Systems, ICES 2007
Country/TerritoryUnited States
CityChicago, IL

ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering


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