Home   >   CSC-OpenAccess Library   >    Manuscript Information
Effect of Bend Curvature Ratio on Flow Pattern at a Mixing Tee after a 90 Degree Bend
Mohammad Reza Nematollahi, Mazyar Asmani, Mohammad Nazififard, Hidetoshi Hashizumeh
Pages - 478 - 487     |    Revised - 30-10-2009     |    Published - 30-11-2009
Volume - 3   Issue - 5    |    Publication Date - November 2009  Table of Contents
Mixing Phenomena, Secondary Flow, Phenix reactor
• Many nuclear power plants report high cycle thermal fatigue in their cooling system, caused by temperature fluctuation in a non-isothermal mixing area. One of these areas is the T-junction, in which fluids of various temperatures and velocities blend. The objective of this research is to classify turbulent jet mechanics in order to examine the flow-field structure under various operating conditions. Furthermore, this research discovers the optimum operating conditions of the mixing tee in this piping system. An experimental model, including the T-junction with a 90 degree bend upstream, is operated to analyze this mixing phenomenon based on the real operation design of the Phenix Reactor. The temperature and velocity data show that a 90 degree bend has a strong effect on the fluid mixing mechanism and the momentum ratio between the main velocity and the branch velocity of the T-junction, which could be an important parameter for the classification of the fluid mixing mechanism. By comparing their mean velocity distributions, velocity fluctuations and time-series data, the behavior of the branch jet is categorized into four types of turbulent jets; sorted from the highest to the lowest momentum ratios, the jets are categorized as follows: the wall jet, the re-attached jet, the turn jet, and the impinging jet. Ultimately, the momentum ration of the turn jet was selected as the optimum operating condition as it has the lowest velocity and the lowest temperature fluctuations near the wall of the mixing tee. By changing the bending ratio from 1.41 to 1.0 the results show that most of data are in the turn jet region. Therefore, with the sharpened bend, the re-attached region is compressed.
CITED BY (3)  
1 Sochi, T. (2015). Fluid flow at branching junctions. International Journal of Fluid Mechanics Research, 42(1).
2 Hutli, e., gottlasz, v., farkas, i., ézsöl, g., & baranyai, g. investigation of mixing coolant in a model of reactor vessel down-comer and in cold leg inlets using piv, lif, and cfd techniques.
3 Gallego Marcos, I. (2013). Thermal Mixing CHT Simulations with OpenFOAM: URANS and LES.
1 Google Scholar 
2 Academic Journals Database 
3 Academic Journals Database 
4 ScientificCommons 
5 CiteSeerX 
6 refSeek 
7 iSEEK 
8 ResearchGATE 
9 Libsearch 
10 Libsearch 
11 Bielefeld Academic Search Engine (BASE) 
12 Scribd 
13 WorldCat 
14 SlideShare 
15 SlideShare 
16 PdfSR 
18 Chinese Directory Of Open Access 
19 Chinese Directory Of Open Access 
Faidy C., “EPRI-US NRC-OECD NEA”. In Third International Conference on Fatigue of reactor Components, Seville, Spain, 2004
H.C. Kao. “Some aspects of bifurcation structure of laminar flow in curved ducts”, J. Fluid Mech., pp. 519–539(1992).
Hosseini S.M. “ Experimental investigation of thermal-hydraulic characteristics at a mixing tee, in”.In International Heat Transfer Conference, FCV-17, Sydney, Australia, 2006.
Hosseini S.M. “ The three-dimensional study of flow mixing phenomenon”. In International Conference Nuclear Energy for New Europe, ID: 037, Bled, Slovenia, September 2005.
Hosseini S.M. “ Visualization of fluid mixing phenomenon”. Sixth International Congress on Advances in Nuclear Power Plants, ICAPP05, ID: 5006 (R006), Seoul, Korea, May 2005.
Igarashi M. “Study on Fluid Mixing Phenomena for Evaluation of Thermal Striping in A Mixing Tee”. In 10th International Topical Meeting on Nuclear Reactor Thermal Hydraulic, NURETH-10, Seoul, Korea, 2003.
Yuki K. “ vol. 2, 2001, pp. 1573–1578”. In Proceedings of the Fifth World Conference on Experimental Heat Transfer Fluid Mechanics and Thermodynamics, Japan, 2004.
Yuki K. “ID: N6P082”.In Proceedings of the 15th International Conference on Nuclear Thermal Hydraulic, Operation and Safety (NUTHOS-6), Nara, Japan, 2004.
Assistant Professor Mohammad Reza Nematollahi
- Iran
Mr. Mazyar Asmani
Shiraz University - Iran
Mr. Mohammad Nazififard
Shiraz University - Iran
Professor Hidetoshi Hashizumeh
Tohoku University - Japan