Barber Nichols - Axial Flow Impulse Turbines

Axial Flow Impulse Turbines achieve the full pressure ratio across the nozzle and capture the kinetic energy via the turbine blades.  Impulse turbines are ideally suited for applications where you need to keep the speed of the machine and the tangential velocity of the rotor low. In other words, they are often used in a lower specific speed range. For power generation systems, it is advantageous to operate at 3,600 rpm in order to drive a synchronous generator. In aerospace or other high-power-density systems, the driving fluid is typically very energetic resulting in a high enthalpy drop across the turbine.  For such applications, the impulse turbine can operate efficiently at a lower tangential velocity than reaction turbines. For lower flow applications, the impulse turbine can effectively operate with a partial admission nozzle outperforming a comparable reaction turbine.