Pulsed Light Emitting Diodes for Particle Image Velocimetry in a Vertically Submersible Pump

Vertically submersible pumps are widely used in water intake systems. To enable the efficient, safe and reliable operation of submersible pumps, flow patterns towards the pumps are examined in scale model tests, or through computational fluid dynamics (CFD) simulations. In order to validate these simulations, detailed, high resolution velocity measurements are required, which can be obtained by Particle Image Velocimetry (PIV). Currently, the application of PIV in industrial physical scale models is limited, due to laser safety precautions and limitation to the expanding of the laser sheet. A possible solution for these challenges is the use of a light emitting diode (LED) as light source for PIV. To examine this in large scale-models, 2D planar PIV measurements of the flow field in and around the bell mouth of a vertically submersible pump have been performed with a pulsed LED as light source. At different discharge levels, the flow patterns in and around the bell mouth are instantaneously measured. The time-averaged PIV results are compared with pitot tube measurements and CFD simulations. It is concluded that PIV measurements can be performed using an LED as a light source in an industrial physical scale model, for flow velocities up to 4.0 m/s.