Prediction of vortex penetration depth at thermal stratification by cavity flow in a branch pipe with closed end (effect of heat radiation condition on temperature fluctuations)
✍ Scribed by Kouji Shiina; Tsutomu Kawamura; Masaya Ohtsuka; Tadashi Mizuno; Masakazu Hisatsune; Kenji Ogura; Kouichi Tanimoto; Toshihiko Fukuda; Yasuhiko Minami; Shoichi Moriya; Haruki Madarame
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 924 KB
- Volume
- 36
- Category
- Article
- ISSN
- 1099-2871
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✦ Synopsis
Abstract
In a branch pipe with one closed end, the cavity flow penetrates into the branch pipe from the main loop and a thermal boundary layer occurs because the cavity flow is a hot fluid, but heat removal causes a colder fluid in the branch pipe. This thermal stratification may affect the structural integrity. Therefore, a pipe design standard to suppress thermal fatigue should be established. The pipe design standard consists of the maximum penetration depth L~sv~ and the minimum penetration depth L~sh~. In order to establish an evaluation method for L~sh~, a visualization test and a temperature fluctuation test were carried out. A theoretical formula for thermal stratification was introduced from the heat balance model. Then the model was used to obtain an empirical equation from the map of fluid temperature fluctuation. This method can predict the vortex penetration depth by cavity flow in horizontal branch pipes. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(1):38–55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20135