Thin Film Measurement Assessment of the VPCAR Water Recovery System in Partial and Microgravity 2007-01-3039
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.
Citation: Hall, N., Niederhaus, C., Mackey, J., Litwiller, E. et al., "Thin Film Measurement Assessment of the VPCAR Water Recovery System in Partial and Microgravity," SAE Technical Paper 2007-01-3039, 2007, https://doi.org/10.4271/2007-01-3039. Download Citation
Author(s):
Nancy Rabel Hall, Charles Niederhaus, Jeffrey Mackey, Eric Litwiller, Michael Flynn
Affiliated:
NASA Glenn Research Center
Pages: 11
Event:
International Conference On Environmental Systems
ISSN:
0148-7191
e-ISSN:
2688-3627
Related Topics:
Microgravity
Heat transfer
Gravity
Energy consumption
Aircraft
Forming
Wipers and washers
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