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Abstract: We focused mainly on a uniform air flow distribution design strategy for a multi-perforated air supply duct with a multi-blade opposed regulation damper. This design is especially required in tunnel transverse ventilation systems, in which a uniform air flow distribution is needed to dilute vehicle exhaust gases or vehicle emissions to acceptable concentrations. First, local resistance coefficients arising when air flows out of the duct through the damper were investigated by means of dimensional analysis and computational fluid dynamics (CFD) simulation, and a mutual authentication was performed with 3D and 2D simulation results. This revealed that the ratio of the velocity in the duct and the damper, and the blade opening angle are the two main factors affecting the resistance coefficient. Second, theoretical analysis based on Bernoulli’s equation was implemented to establish the relationship between the local resistance coefficient and the pressure drop. Based on the simulation results, a uniform air flow distribution design strategy corresponding to the opening angle adjustment was obtained. Finally, a calculation case study was carried out, and sufficient consistency between the theoretical and numerical calculation results was achieved, verifying the reliability of the design strategy.

This paper mainly provides 1) interesting reference data of loss coefficient values for a particular type of damper and 2) an elegant analytical method for designing duct systems for equal airflow from each outlet.

隧道横向式通风系统中的等量送风设计方法研究

[1]Ascough GW, Kiker GA, 2002. The effect of irrigation uniformity on irrigation water requirements. Water SA, 28(2):235-242.

[2]Chen A, Sparrow EM, 2009a. Effect of exit-port geometry on the performance of a flow distribution manifold. Applied Thermal Engineering, 29(13):2689-2692.

[3]Chen A, Sparrow EM, 2009b. Turbulence modeling for flow in a distribution manifold. International Journal of Heat and Mass Transfer, 52(5-6):1573-1581.

[4]El Moueddeb K, Barrington S, Barthakur N, 1997. Perforated ventilation ducts: part 1, a model for air flow distribution. Journal of Agricultural Engineering Research, 68(1):21-27.

[5]Farajpourlar M, 2017. On the prediction of uniformity of air flow out from manifold distribution. Materialwissenschaft und Werkstofftechnik, 48(3-4):249-254.

[6]Foust J, Rockwell D, 2007. Flow structure associated with multiple jets from a generic catheter tip. Experiments in Fluids, 42(4):513-530.

[7]Ibukiyama S, 1957. The calculation methods of static pressures in the ventilation ducts of uniform area with slots of equal size at equal intervals and opening areas of those slots. Transactions of the Japan Society of Civil Engineers, 47:30-37.

[8]Ji CZ, Zhang X, Jiang M, et al., 2010. Numerical simulation of influence of 90°-bend pipeline geometric shape on local loss coefficient. International Conference on Mechanical and Electrical Technology, p.668-672.

[9]Jo HJ, Chun KM, Min DK, et al., 2017. A study on the program development for optimizing the supply and exhaust port opening ratio in road tunnels with transverse ventilation system. Journal of Korean Tunnelling and Underground Space Association, 19(3):517-532.

[10]Kalpakli A, Örlü R, 2013. Turbulent pipe flow downstream a 90° pipe bend with and without superimposed swirl. International Journal of Heat and Fluid Flow, 41:103-111.

[11]Kareeri AA, Zughbi HD, Al-Ali HH, 2006. Simulation of flow distribution in radial flow reactors. Industrial & Engineering Chemistry Research, 45(8):2862-2874.

[12]Kim S, Choi E, Cho YI, 1995. The effect of header shapes on the flow distribution in a manifold for electronic packaging applications. International Communications in Heat and Mass Transfer, 22(3):329-341.

[13]Lee S, Moon N, Lee J, 2012. A study on the exit flow characteristics determined by the orifice configuration of multi-perforated tubes. Journal of Mechanical Science and Technology, 26(9):2751-2758.

[14]Lesser N, Horowitz F, King K, 1987. Transverse ventilation system of the Holland tunnel evaluated and operated in semi-transverse mode. Transportation Research Record, 1150:24-28.

[15]Li JSM, Chow WK, 2003. Numerical studies on performance evaluation of tunnel ventilation safety systems. Tunnelling and Underground Space Technology, 18(5):435-452.

[16]Oliveira PJ, Pinho FT, 1997. Pressure drop coefficient of laminar Newtonian flow in axisymmetric sudden expansions. International Journal of Heat and Fluid Flow, 18(5):518-529.

[17]Rong GW, Wei WL, Liu YL, 2010. 3D numerical simulation for hydraulic characteristics of turbulent flow in bifurcated duct. Journal of Hydraulic Engineering, 41(4):398-405 (in Chinese).

[18]Singh RK, Rao AR, 2009. Simplified theory for flow pattern prediction in perforated tubes. Nuclear Engineering and Design, 239(10):1725-1732.

[19]VanGilder JW, Schmidt RR, 2005. Airflow uniformity through perforated tiles in a raised-floor data center. AMSE Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems Collocated with the ASME, p.493-501.

[20]Wang J, Priestman GH, Wu D, 2001. A theoretical model of uniform flow distribution for the admission of high-energy fluids to a surface steam condenser. Journal of Engineering for Gas Turbines and Power, 123(2):472-475.

[21]Ye WB, 2017. Design method and modeling verification for the uniform air flow distribution in the duct ventilation. Applied Thermal Engineering, 110:573-583.

[22]Yu HQ, 2013. Engineering Fluid Mechanics (3rd Edition). Southwest Jiaotong University Press, Chengdu, China, p.122-128 (in Chinese).