The following information was submitted:
Transactions: WSEAS TRANSACTIONS ON FLUID MECHANICS
Transactions ID Number: 89-434
Full Name: Chao-Jen Li
Position: Doctor (Researcher)
Age: ON
Sex: Male
Address: Rm. 637, Bldg. 52, 195, Sec.4, Chung Hsing Rd., Chutung, Hsinchu, Taiwan 31040, R.O.C.
Country: TAIWAN
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E-mail address: lichaojen@itri.org.tw
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Title of the Paper: Two different turbulence models in comparison with experiments on thermal mixing phenomenon in a tee piping
Authors as they appear in the Paper: Chao-Jen Lli,Yao-Long Tsai,Tai-Ping tsai,Li-Hua Wang
Email addresses of all the authors: lichaojen@itri.org.tw,YLtsai@itri.org.tw,tptsai@itri.org.tw,LIWANG@itri.org.tw
Number of paper pages: 10
Abstract: Thermal fatigue failures in reactor cooling systems of nuclear power plants are caused by the fluctuating stresses on a piping system due to the hot and cold flows are mixed together in a mixing piping. The present paper describes BSL Reynolds Stress (BSL-RSM) and k-epsilon (k-£`) simulation data of thermal mixing in a mixing piping compared with results from experimental data. The fluid in the experiment is concentration of de-ionized water and the liquid electrical conductivities are measured by the use of the 16¡Ñ16 electrode. To verify the mixing phenomenon between de-ionized water with different electrical conductivities and water with different temperatures, the inlet temperatures of the hot and cold water in the simulation process are set to 80¢J and 15¢J respectively. The analytic results calculated by the commercial CFD code ANSYS CFX 11.0 show that the different turbulence models¡]BSL-RSM, k-£`¡^and different turbulent Prandtl numbers¡]0.9, 0.2, 0.1¡^will!
affect the simulation results of temperature fluctuations. Since the coefficient of determination, R2, obtained by using Prt=0.1 for BSL-RSM turbulence mode is between 0.996 and 0.788, which is higher than that by using Prt=0.2 and Prt=0.9, the perditions for smaller turbulent Prandtl number are in better agreement with measurements. The absolute error, £], obtained by using BSL-RSM turbulence model at x=0.025m is smaller than that by using k-£` turbulence model. However, at x=-0.025m, the absolute error, £], obtained by using k-£` turbulence model is smaller than that by using BSL-RSM turbulence model. The computational results are in qualitative good agreement with experimental data that the mixing phenomenon of water with two different temperatures can be explained by de-ionized water with two different electrical conductivities.
Keywords: RSM¡Bk-£`¡BThermal Fatigue¡BTurbulent Prandtl Number¡BMixing
EXTENSION of the file: .pdf
Special (Invited) Session: experiments and two different turbulence models comparisons on thermal mixing phenomenon in a tee piping
Organizer of the Session: 643-219
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