Research Containing: Perturbation

The Capillary Flow Experiment (CFE) consists of six approximately 2kg test vessels constructed by NASA to probe certain capillary phenomena of fundamental and applied importance. The light weight, low-volume hardware can be shipped to orbit on short notice as cargo space permits and the experiment performed in stand-alone mode by a single crewmember on, for example, the Maintenance Work Area (workbench) of the International Space Station. Video images from the simply performed crew procedures provide highly quantitative data for the confirmation of current analytical design tools as well as directions for further theoretical development. This paper presents a narrative of preliminary results from the first Capillary Flow Experiment (CFE) conducted aboard ISS in August-September 2004. The tests are performed as per of NASA’s Saturday Morning Science Program on ISS and completed in good order by Astronaut Michael Fincke who collected approximately 100 data sets that compare large length scale capillary surface oscillations and damping for two otherwise identical cylindrical tanks differing only in respect to a critical yet uncertain boundary condition at the contact line. Linear, nonlinear, and destabilizing slosh, swirl, axial, and other disturbances are studied. The large data set is being reduced for comparisons to the blind predication of a group of numerical analysis assembled to gauge the accuracy of present methods to predict large length scale capillary dynamics critical to fluids management in spacecraft (i.e. fuels, cryogens, water). The success of the experiment reported herein serves as a testimony to astronaut ingenuity and the perhaps surprisingly flexible fluids laboratory of the ISS for safe and simple fluids experimentation.

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This paper provides a current overview of the in-flight operations and experimental results of the capillary flow experiment (CFE) performed aboard the International Space Station (ISS) beginning August 2004 to present, with at least 16 operations to date by five astronauts. CFE consists of six approximately 1–2 kg experiment units designed to probe certain capillary phenomena of fundamental and applied importance, such as capillary flow in complex containers, critical wetting in discontinuous structures, and large length scale contact line dynamics. Highly quantitative video images from the simply performed experiments provide direct confirmation of the usefulness of current analytical design tools as well as provide guidance to the development of new ones. A description of the experiments, crew procedures, performances and status of the data collection and reduction is provided for the project. The specific experimental objectives are briefly introduced by way of the crew procedures and a sample of the verified theoretical predictions of the fluid behavior is provided. The potential impact of the flight experiments on the design of spacecraft fluid systems is discussed in passing.

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http://www.sciencedirect.com/science/article/pii/S0094576509001386

This paper provides a summary of the experimental, analytical, and numerical results of the Capillary Flow Experiment (CFE) performed onboard the International Space Station (ISS) from Increment 9 (beginning August, 2004) through Increment 16 (ending December, 2007), with 19 operations by 7 astronauts; M. Fincke, W. McGarthur, J. Williams, S. Williams, M. Lopez-Alegria, C. Anderson, and P. Whitson. CFE consists of 6 approximately 1 to 2kg experiment units designed to probe certain capillary phenomena of fundamental and applied importance, such as capillary flow in complex containers, critical wetting in discontinuous structures, and large length scale contact line dynamics. Highly quantitative video images from the simply performed flight experiments provide immediate confirmation of the usefulness of current analytical design tools as well as provide guidance to the development of new ones. A brief review of the experiments and procedures is provided before reporting the status of the data collection, reduction, and comparisons with both analytic and numerical predictions. The products of the work include design tools for modeling capillary interface dynamics relevant to spacecraft engineering systems. The CFE experimental program was initiated in February 2003 as part of a fast-paced unscheduled payloads/experiments program. All six of the units were performed on standby or at times as part of NASA Saturday Science and all units have been returned to Earth for post flight analysis. The experiments were conducted in stand-alone mode by a single crewmember on the Maintenance Work Area of the ISS.

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