Constrained Vapor Bubble Heat Pipe Experiment Aboard the International Space Station

2013 ◽  
Vol 27 (2) ◽  
pp. 309-319 ◽  
Author(s):  
Arya Chatterjee ◽  
Joel L. Plawsky ◽  
Peter C. Wayner ◽  
David F. Chao ◽  
Ronald J. Sicker ◽  
...  
Author(s):  
Arya Chatterjee ◽  
Joel L. Plawsky ◽  
Peter C. Wayner ◽  
David F. Chao ◽  
Ronald J. Sicker ◽  
...  

The constrained vapor bubble (CVB) experiment is an experiment in thermal fluid science currently operating on the International Space Station. Flown as the first experiment on the Fluids Integrated Rack on the Destiny module of the US part of the space station, the experiment promises to provide new and exciting insights into the working of a wickless micro heat pipe in the micro-gravity environment. The CVB consists of a relatively simple setup — a quartz cuvette with sharp corners partially filled with pentane as the working fluid. Along with temperature and pressure measurements, the curvature of the pentane menisci formed at the corners of the cuvette can be determined using optical measurements. This is the first time the data collected in space environment is being presented to the public. The data shows that, while the performance of the CVB heat pipe is enhanced due to increased fluid flow, the loss of convection as a heat loss mechanism in the space environment, leads to some interesting consequences. We present some significant differences in the operating characteristics of the heat pipe between the space and Earth’s gravity environments and show that this has important ramifications in designing effective radiators for the space environment.


2010 ◽  
Vol 24 (2) ◽  
pp. 400-410 ◽  
Author(s):  
Arya Chatterjee ◽  
Joel L. Plawsky ◽  
Peter C. Wayner ◽  
David F. Chao ◽  
Ronald J. Sicker ◽  
...  

Author(s):  
Joel L. Plawsky ◽  
Peter C. Wayner

The Constrained Vapor Bubble (CVB) is a prototype for a wickless heat pipe and was developed into an experiment that was run in the microgravity environment of the International Space Station during 2010. Since the CVB is transparent, we can visualize the flow processes within the device in a way not possible before. Results from the experiment indicate that the CVB operates at higher pressures and temperatures in microgravity, a consequence of radiation being the only mechanism for removing heat from the device. The temperature profile data along the heat pipe and corresponding heat transfer calculations indicate that CVB performance is enhanced in the microgravity environment due to increased capillary flow even though heat transfer to the external environment is diminished by the absence of natural convection. Image data of the liquid profile in the grooves of the heat pipe indicate that the curvature gradient is considerably different from that on Earth and supports the conclusion that capillary flow and internal heat transfer is increased. Operations with the 20 mm version of the device allowed us to view explosive nucleation within the CVB upon device start-up. In this scenario, bubble nucleation occurred spontaneously and periodically at the hot end of the device. The nucleation process sent a shock wave through the pipe that collapsed the original bubble as a new vapor space was generated. The newly formed bubble returned to its original size, shape and location as heat loss from the CVB reestablished the original, pseudo-steady-state temperature and pressure profiles.


2005 ◽  
Author(s):  
Danielle Paige Smith ◽  
Vicky E. Byrne ◽  
Cynthia Hudy ◽  
Mihriban Whitmore

2020 ◽  
Vol 91 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Virginia. E. Wotring ◽  
LaRona K. Smith

INTRODUCTION: There are knowledge gaps in spaceflight pharmacology with insufficient in-flight data to inform future planning. This effort directly addressed in-mission medication use and also informed open questions regarding spaceflight-associated changes in pharmacokinetics (PK) and/or pharmacodynamics (PD).METHODS: An iOS application was designed to collect medication use information relevant for research from volunteer astronaut crewmembers: medication name, dose, dosing frequency, indication, perceived efficacy, and side effects. Leveraging the limited medication choices aboard allowed a streamlined questionnaire. There were 24 subjects approved for participation.RESULTS: Six crewmembers completed flight data collection and five completed ground data collection before NASA’s early study discontinuation. There were 5766 medication use entries, averaging 20.6 ± 8.4 entries per subject per flight week. Types of medications and their indications were similar to previous reports, with sleep disturbances and muscle/joint pain as primary drivers. Two subjects treated prolonged skin problems. Subjects also used the application in unanticipated ways: to note drug tolerance testing or medication holiday per research protocols, and to share data with flight surgeons. Subjects also provided usability feedback on application design and implementation.DISCUSSION: The volume of data collected (20.6 ± 8.4 entries per subject per flight week) is much greater than was collected previously (<12 per person per entire mission), despite user criticisms regarding app usability. It seems likely that improvements in a software-based questionnaire application could result in a robust data collection tool that astronauts find more acceptable, while simultaneously providing researchers and clinicians with useful data.Wotring VE, Smith LK. Dose tracker application for collecting medication use data from International Space Station crew. Aerosp Med Hum Perform. 2020; 91(1):41–45.


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