Physical and Numerical Modelling of a Tangential Vortex Intake for Supercritical Storm Flow Diversion
In densely populated cities, urban flood control often requires the use of compact drainage structures. A compact bottom rack chamber with tangential vortex intake structure has recently been developed for diverting fast moving turbulent flow on steep catchment into a drainage tunnel for discharge into the sea. The flow in this newly developed intakes structure (generic design) is threedimensional, turbulent and highly aerated. During the detailed design of the intake structure, it has been necessary to adopt a mirror-image orientation of the tangential inlet alignment so as to suit particular site constraints. A 1:16 physical model of the proposed tangential vortex intake has been carried out. The performance characteristics of the proposed design are compared with those of the generic design. The complex 3D flow in the interception and tangential vortex intake structure are investigated by both the Froude-scale physical model and computational fluid dynamics (CFD) modeling using the FLOW3D software. In the numerical model, the airwater flow is simulated using the Volume of Fluid (VOF) method) turbulence closure is made via a twoequation k -e model. Experimental results show the supercritical flow along the tangential vortex intake is characterized by flow impingement; it is highly non-uniform and the shockwave height reduces towards the downstream end. The air core size in the dropshaft is adequate for the design flow. The computed flow depth variation in the tangential inlet are in reasonable agreement with the experimental data) the major flow features can be simulated. Both the physical and numerical model results show insignificant differences in the drainage performance of the proposed and generic designs.
Colin K.C.Wong Joseph H.W.Lee
Croucher Laboratory of Environmental Hydraulics, Department of Civil Engineering,The University of Hong Kong, Pokfulam, Hong Kong, China
国际会议
南京
英文
189-195
2010-09-13（万方平台首次上网日期，不代表论文的发表时间）