Browse > Article

Effect of a Variation of a Main Duct Area on Flow Distribution of Each Branch  

Lee Jai-Ho (Graduate School of Mech Eng., Chonbuk National Univ.)
Kim Beom-Jun (Graduate School of Mech Eng., Chonbuk National Univ.)
Cho Dae-Jin (Graduate School of Mech Eng., Chonbuk National Univ.)
Yoon Suck-Ju (Dept. of Mech Eng., Automobile Hi-Technology Research Center, Chonbuk National Univ.)
Publication Information
Korean Journal of Air-Conditioning and Refrigeration Engineering / v.17, no.4, 2005 , pp. 386-395 More about this Journal
Abstract
With the development of a living standard, the importance of indoor air conditioning system in all kinds of buildings and vehicles has increased. A lot of researches on energy losses in a duct and various kinds of flow pattern in branches or junctions have been carried out over many years, because the primary object of a duct system used in HVAC is to provide equal flow rate in the interior of each room by minimizing pressure drop. In this study, to get equal flow distribution in each branch, a blockage is applied to the rectangular duct system. The flow analysis for flow distribution of a rectangular duct with two branches was performed by CFD. By using SIMPLE algorithm and finite volume method, flow analysis is performed in the case of 3-D, incompressible, turbulent flow. Also, the standard $k-{\varepsilon}$ model and wall function method were used for analysis of turbulent fluid flow. The distribution diagrams of static pressure, velocity vector, turbulent energy and kinetic energy in accordance with variation of Reynolds number and blockages location in a rectangular duct show that flow distribution at duct outlets is improved by a blockage. In this rectangular duct system, mean velocity and flow rate distribution in two branch outlets are nearly constant regardless of variation of Reynolds number, and a flow pattern of the internal duct has a same tendency as well.
Keywords
Rectangular duct; Flow distribution; Aspect ratio; Blockage ratio; Separated flow;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Hinchcliffe, S. and Haidar, N., 1998, CFD investigation into LD100 HVAC ducting system, Technical Review, pp.145-152
2 Lee, D. H. and Kwon, Y. P., 1994, Computer program for pressure drop and sound transmission in a duct system, Air-Conditioning and Refrigeration Engineering, Magazine of SAREK, Vol. 23, No.3, pp.191-203
3 Shiroyama, M., Ijawa, T. and Hasegawa, T., 1998, Development of compact air conditioning for vehicle using CFD, J. of Mitsuvishi Heavy Industry, Vol. 35, No.2, pp. 108-111
4 Jeong, S. J., Ryu, S. Y. and Kim, T. H., 1996, Numerical analysis of three dimensional turbulent flow in a HVAC duct, KSAE, Vol. 4, No.4, pp. 118-129
5 Shao, L. and Riffat, S. B., 1997, CFD for prediction of k-factors of duct fitting, International Journal of Energy Research, Vol.19, pp. 675-68I
6 Arkin, H. and ShitzerI, A., 1979, Computer aided optimal life-cycle design of rectangular air supply duct systems, ASHRAE Transactions, Vol. 85, Part 1, pp.197-213
7 Lin, C. H., Han, T. Y. and Sumantran, U., 1994, Experimental and computational studies of flow in a simplified HVAC duct, Int. J. of Vehicle Design, Vol. 15, No. 1/2, pp.147-165
8 Tohru, Komoriya, 1991, Numerical simulation of the flow in a vehicle passenger compartment using finite volume method, JSAE Review, Vol. 12, No.3, pp.36-4I
9 Kim, M. H., Chyun, I. B. and Lee, D. H., 2002, A numerical analysis on the optimum design of a duct with multiple outlets in a medium bus, KSAE, Vol. 10, No.4, pp.94-107
10 2004, STAR-CD Users' Manual, Ver.3.22, Computational Dynamics Ltd
11 Shao, L. and Riffat, S. B., 1995, Accuracy of CFD for predicting pressure losses in HVAC duct fitting, Applied Energy, Vol. 51, No.3, pp. 233-248   DOI   ScienceOn
12 Yoon, Y. H., Bae, T. H. and Park, W. G., 2002, Experimental and computational studies for flow distribution in a rectangular duct system with two branches, Korean journal of the SAREK, Vol. 14, No.9, pp.766-773
13 Gan, G. and Riffat, S. B., 2000, Numerical determination of energy losses at duct junctions, Applied Energy, Vol. 67, pp.331-340   DOI   ScienceOn