How does Kaplan turbine operate?
The Kaplan turbine is an inward flow reaction turbine, which means that the working fluid changes pressure as it moves through the turbine and gives up its energy. Power is recovered from both the hydrostatic head and from the kinetic energy of the flowing water. The design combines features of radial and axial turbines. The inlet is a scroll-shaped tube that wraps around the turbine's wicket gate. Water is directed tangentially through the wicket gate and spirals on to a propeller shaped runner, causing it to spin. The outlet is a specially shaped draft tube that helps decelerate the water and recover kinetic energy. The turbine does not need to be at the lowest point of water flow as long as the draft tube remains full of water. A higher turbine location, however, increases the suction that is imparted on the turbine blades by the draft tube. The resulting pressure drop may lead to cavitation. Kaplan turbine efficiencies are typically over 90%, but may be lower in very low head applications.
How to Calculate Velocity of flow at inlet?
Velocity of flow at inlet calculator uses Flow Velocity at Inlet = Volume Flow Rate/(pi/4*(Outer Diameter of Runner^2-Diameter of Hub^2)) to calculate the Flow Velocity at Inlet, The Velocity of flow at inlet formula is used to find the flow velocity in an axial flow turbine when volume flow rate and diameter of hub and runner are known. Flow Velocity at Inlet is denoted by Vfi symbol.
How to calculate Velocity of flow at inlet using this online calculator? To use this online calculator for Velocity of flow at inlet, enter Volume Flow Rate (Q), Outer Diameter of Runner (Do) & Diameter of Hub (Db) and hit the calculate button. Here is how the Velocity of flow at inlet calculation can be explained with given input values -> 5.999297 = 43.29/(pi/4*(3.5^2-1.75^2)).