Simulation and Cryogenic Experiments of Natural Convection for the Titan Montgolfiere
Abstract
Natural convection in a spherical geometry is considered for prediction of the buoyancy of single- and double-walled balloons in a cryogenic environment such as Titan's atmosphere. The steady-state flow characteristics obtained by solving the Reynolds-averaged Navier–Stokes equations with a standard turbulence model are used to determine the net buoyancy as a function of heat input. Thermal radiation effects are shown to have a minor impact on the buoyancy, as would be expected at cryogenic conditions. The predicted buoyancy and temperature fields compare favorably with experiments preformed on a 1-m-diameter Montgolfiere prototype in a cryogenic facility. In addition, both numerical and experimental results were compared with correlations for the heat transfer coefficients for free convection internal and external to the balloon as well as in the concentric gap of the double-walled balloons. Finally, scaling issues related to inferring the performance of the full-scale Montgolfiere from the model-scale results are examined.
Additional Information
© 2012 by the American Institute of Aeronautics and Astronautics. Presented at the 19th AIAA Lighter-Than-Air Technology Conference, Virginia Beach, VA, September 20–22, 2011; received 12 October 2011; revision received 20 March 2012; accepted for publication 22 March 2012. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. The help and support of test engineers Tim Zhang, Danh Huynh, and Phu Pham as well as technician Huan Phan atWyle Labs, where the cryogenic testing was completed, is gratefully acknowledged. We are also thankful to Arnab Samanta and Julian Nott for their valuable advice during this project.Additional details
- Eprint ID
- 35905
- Resolver ID
- CaltechAUTHORS:20121211-102852653
- NASA/JPL/Caltech
- Created
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2012-12-12Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field