超大且延時降雨產生極端大量的逕流水，輕易地使得許多下水道系統疏流能力突然間不足。當管道中水位上升到某一個點時，地勢相對低窪的地方可能已遭水淹沒，造成居民財產的損壞、潛在的危險與環境污染。不同的流量控制器具有不同的水力特徵，特別是應用於排水網與其上游儲存利用。雨水人孔排水管之排水量係決定在上游的水位高度，漩渦限流裝置(VFRs)它可在一定的出入口尺寸、依據渦室幾何尺寸與上游水壓條件產生定流量的水力特徵；亦即在一定水理條件，採用漩渦限流裝置達到低水位增量排水、定水位限量排水與高水位等量排水等的連續模式。
本研究著重於徑向漩渦限流裝置的應用，藉由限水位或限水量方法達到控制排水的目的，而減少下游淹水的一種排水控制器的設計，開發和測試。試驗部份則著眼於徑向漩渦限流裝置的幾何尺寸與測試曲線驗證。
本研究依據此一理念，開發漩渦限流裝置與水理試驗場，對設計的徑向漩渦限流裝置進行測試和探討，瞭解改變徑向漩渦限流裝置幾何變量對其性能曲線的影響。
以五個不同尺寸徑向漩渦限流裝置模型，在一個給定的水量與水壓的水力試驗設備下，試驗並分析漩渦限流裝置的幾何尺寸關係。
試驗結果取最佳化漩渦限流裝置的幾何尺寸，為入口與出口面積比為1:1 ，渦室直徑為出口4.4 倍可以得到最佳化的排水曲線；漩渦限流裝置在Kick back flow point之前所產生之Flush flow 累積排水量為50m m 孔口累積排水量之1.537 倍。證明漩渦限流裝置可有效快速排除降雨初期之進流水量。

關鍵字:都市排水，淹水，漩渦限流裝置，最佳化效能，排水量曲線。

Experimental study on the characteristics and discharge curve of vortex flow restrictor

Author: Yang, Jen-Chang
Advisor: Professor Leu, Jan-Mou
Department of Hydraulic & Ocean Engineering¸ National Cheng Kung University

Summary

Vortex Flow Restrictor (VFRs) It can produce a constant hydraulic characteristic depending on the geometry of the vortex chamber and inlet and outlet opening, with an upstream water level and conditions. It use of Vortex Flow Restrictor to reaches the low water level incremental drainage, fix water level to obtain a constant drainage and high water level obtain a equivalent flow to compare an orifice which draining under of the continuous mode.
This study focuses on the application of radial Vortex Flow Restrictor, with the purpose of limiting the water level to reduce flooding downstream of a drainage controller design, development and testing. Test portion is aimed at limiting the radial vortices and the geometry of the device to verify the test characteristic curve.
In five different sizes radial vortex flow restrictor model in a given amount of water and the hydraulic pressure test equipment, test and analyze the relationship between the geometry of the vortex current limiting device.
Take the test results to optimize the geometry of the vortex flow restrictor for the inlet and outlet area ratio is 1:1, the outlet diameter is 4.4 times of the swirl chamber can be optimized drainage curve. The accumulated Flush flow of Vortex Flow Restrictor before Kick back flow point arising is 1.537 times.of the accumulated discharge amount of 50mm orifice. Vortex Flow Restrictor proved rapidly and effectively drainage capacity in the beginning of rainfall.

Key Word: Urban Drain, Flood, Vortex flow Restrictor, Optimize performance, Discharge curve.

Introduction

In global climate change coupled with land development and construction boom, has made traditional drainage systems such as runoff pipes, drainage channels or sink, lots of rain is overloaded, making the downstream drainage system overflowed, catharsis is not easy, resulting in many villages in the region, massive flooding in towns and cities.
How to use the upstream drains before untapped assimilative space, slowing the flood situation downstream, the use of road-side ditch can be submerged assimilative space and height, in the main channel runoff water import, set the flow control device , slowing the pipeline was hold big rain overloaded. Currently, the most effective and widely used flow control device is a Vortex flow Restrictor means for limiting the water pressure as the flow rate, i.e., the height of the water tank.

Materials and Methods

By several models test to observe Vortex Flow Restrictor discharge volume change, when the water flow into the swirl chamber inlet of Vortex flow Restrictor, its increase in water pressure and flow rate to follow along the circumference of the vortex chamber size to produce high tangential speed, and then at the outlet pipe forming a vortex gas nuclei (Air Core), limiting the flow.

Results and Discussion

Flow control model results and related performance curve statistical analysis confirmed the Vortex Flow Restrictor means to traditional sewer manhole sewer, water pressure and the resulting vortex effect can be applied to storm drainage curve in rainfall patterns, reaching a low pressure high initial displacement with high water pressure limiting performance hydro applications. The results of experiments can be presented as figures 4.7.2, Vortex Flow Restrictor discharge shown in the graph, R440-100mm displacement increased significantly in Flush point to 8.0Liter / Sec., Kick-Back point also increased to 5.0Liter /Sec., S curve is acting on 400mm ~ 1200mm between.

Figures4.7.2 R440-100 VFR’s discharge curve

Furthermore, R440-100 limiting device swirl orifice than 50mm displacement versus time, as shown in 4.5.3, swirl current limiting device is in low water pressure compared with sparse displacement flow orifice and, at 120 seconds drainage time, whirlpool limiting Flush flow device before Kick back flow point arising from the cumulative displacement of 1.3030 m³, relative aperture of 50mm cumulative displacement of 0.8478 m³, increased 53.7 percent of displacement. Whirlpool proved effective in limiting device into the water quickly ruled out the initial amount of rainfall, the purpose of this study expectations.

Figures4.7.3 R440-100 VFR’s compares to 50mm orifice discharge curve and time changed Figure

Conclusion

This test uses a full-scale design hydraulic test device, by changing the Vortex Flow Restrictor’s opening of outlet diameter which compared to traditional flow of orifice plate. The resulting curve is calculated using the orifice plate outlet with five different test Vortex Flow Restrictor compares the resulting curve, swirl considerable scale shape current limiting device geometry, the use of this relationship we can directly calculate the water level in nominal and drainage flow control requirements, Vortex Flow Restrictor dimensions. After discussion and analysis the following conclusions:
(1) Five different Vortex Flow Restrictor was tested in the same manner hydrostatic pressure to its performance curve liter flow measurement units. The curve follows the general Vortex Flow Restrictor "S" shape, and clearly shows its rose red dot, kick-back point and design flow range. Flush point curve was found to be trapped in the reservoir by a swirl limiting air required additional hydrostatic pressure in the device at the top of the vortex chamber.
(2) The optimal relationship between the different dimensions of the vortex chamber outlet and inlet diameter size to get a relationship with the geometric design variables than 4.4 : 1, the proportional representation of the vortex diameter than the diameter of the opening and exports. An orifice plate flow port has an equal flow of cross-sectional area of 3.97 times the area.
(3) The test Vortex Flow Restrictor before kick-back flow point arising from the cumulative discharge of 50m m orifice cumulative discharge of 1.537 times. Whirlpool proved effective in limiting device into the water quickly ruled out the initial amount of rainfall.

1. 日本規格協會（JIS），公害關係，工業用水、工場排水之試料採取方法，K0094，pp.250～259，1991。
2. 中華民國國家標準(CNS)，工業廢水流量測定法，K9064，1981。
3. 引潮裝置流量係數的研究，李慧梅，陳建國，史紅玲，戴清，(中國水利水電科學研究院 泥沙研究所，北京　100044)
4. 11th International Conference on Urban Drainage, Edinburgh, Scotland, UK, 2008.
5. Andoh, R. Y. G, Stephenson, A. and Kane, A. (2000) Sustainable Urban Drainage using the Hydro Storm cell Storage System. Proc. Standing Conference on Source Control, Coventry University, UK。
6. Andoh, R.Y.G., Faram, M.G., Stephenson, A.G. and Kane, A. (2001) A Novel Integrated System for Storm water Management. Novatech: 4th International Conference on Innovative Technologies in Urban Storm Drainage. Lyon, France, 25-27 June, pp 433−440。
7. Boakes, G. P., Stephenson, A., Lowes, J. B., Morison, A. C. and Osborne, A. T. (2004) Weedon Flood Storage Scheme - the Biggest Hydro-Brake in the World. British Dam Society 13th Biennial Conference, University of Kent, Canterbury, UK, 22-26 June。
8. Chapter 5 Environmental Guidelines For CULVERTS， Water Resources Management Division， Water Investigations Section，February 20, 1992。
9. CIRIA (2004) Sustainable Drainage Systems: Hydraulic, Structural and Water Quality Advice. Authors S.Wilson, R.Bray and P.Cooper, Report C609。
10. Design and Development of a Radial Vortex Flow Control Device，June 2008，Dermot O’Brien。
11. Ellis, J.B. (1991) Urban Runoff Quality in the UK: Problems, Prospects and Procedures. Appl. Geog., 11, 187−200。
12. EC (2000) Directive 2000/60/EC of the European Parliament and of the Council establishing a Framework for the Community Action in the field of Water Policy. Official Journal (OJ L 327), 22 December。
13. Faram, M.G., Guymer, I. and Saul, A.J. (2004) Assessment of Modular Block Storm water Storage Systems. Novatech: 5th 7 International Conference on Sustainable Techniques and Strategies in Urban Water Management, Lyon, France, 6-10， June, pp 235−242。
14. Faram, M. G., Alkhaddar, R. M., Phipps, D. A. and Guymer, I. (2005) Best Practice Approaches to the Management of Sediments in 'Hard' SUDS Structures. Proc 3rd National Conference on Sustainable Drainage, Coventry, 20-21 June, pp 83−93。
15. Faram, M. G. and Iwugo, K. O. I. (2006) Quantification of Persistent Pollutants Captured by Proprietary Stormwater Sediment Interceptors. IWA 10th International Specialized Conference on Diffuse Pollution and Sustainable Basin Management, 18−22 September, Istanbul, Turkey (submitted)。
16. Method and Device For The Control Of Fluid Flow，Nov. 1965，J.D. BOADWAY。
17. Padraig Doyle - SUDS IN THE GREATER DUBLIN AREA, National Hydrology Seminar 2003.