Vortex Formation at Vertical Pipe Intakes

With the object of determining the similarity criterion, experimental studies on vortex formation at pipe intakes were carried out using two geometrically similar circular vortex tanks, circulation in approach flow was generated by means of adjustable guide vanes. Transparent pipe intakes of different sizes and liquids of different viscosities and surface tensions were used in a recirculating system. Based on the analysis of data, a method has been proposed according to which a geometrically similar model is operated at the same Froude number as in the prototype and the observed critical submergence is corrected for distortion due to change in the model Reynolds number. A criterion to determine the type of vortex for known geometric and kinematic conditions has also been proposed.