Vortex Flow Controls (VFCs) are commonly used in drainage schemes to regulate the stormwater runoff from urban areas.
Through the use of vortex flow technology FP McCann’s Stormbrake™ provides solutions to a variety of stormwater management problems. These include accurately controlling stormwater flow, minimising upstream storage requirements and reducing the risk of blockages compared to traditional orifice plates.
What is Vortex Flow Technology?
Vortex flow control technology is based on the hydrodynamic principles of swirling vortex flows. Under sufficiently high upstream water levels, a vortex is induced in the flow by the device. The vortex motion results in significant energy loss, creating a pressure drop across the device and restricting the discharge leaving the outlet. The geometric properties of the device control the amount of flow restriction and can be tailored to suit the design conditions for a specific site.
- Minimal maintenance required after installation. FP McCann’s StormBrake™ is self-activating and functions without any mechanical components
- Outlet areas of up to 6 times larger than an equivalent orifice plate, significantly reducing the risk of blockages and the associated maintenance costs
- Reduces the amount of upstream storage required, minimising the cost of providing attenuation facilities
- Accurately designed to meet a wide range of design conditions: flows between 3 – 4l/s; heads between 0.5 and 2.0m. For design conditions outside of this range, please contact FP McCann directly
- Contains a bypass door which can be manually opened at ground level using a pull cable to allow easy access for inspection or blockage removal
- Provides minimal flow restriction at low upstream heads to allow fast discharge of water during the initial stages of a storm
|Phase||Vortex Flow Regime||Description|
|(i) Pre-vortex phase||Hydrodynamics governed by orifice flow. The flow generated by the upstream head is not large enough to induce a vortex in the StormBrake™. This phase occurs until the flush-flow point is reached.|
|(ii) Transition phase||Flow throttling initiated. Vortex continually forms and collapses, resulting in significant energy loss and lower flow rates despite increasing upstream head. This phase is bounded by the flush-flow and kickback points.|
|(iii) Vortex phase||Vortex fully formed with central air core. The air core imposes a quasi-physical flow restriction, reducing the available area in the pipe for outflow.|