# Reaction Turbine

Pages: 4 (1279 words) Published: February 19, 2011
Reaction Turbine
Nithin Mannil
08d01001
Aim
1.To investigate the Torque/Speed and Power/Speed characteristics of Single Stage Reaction Turbine. 2.To determine the Isentropic Efficiency of a Turbine.
3.To compare the characteristics of a reaction turbine at different values of inlet pressure. 4. To compare the maximum shaft power vs pressure and isentropic efficiency vs pressure. Theory
Turbines are machines which develop torque and shaft power as a result of momentum changes in the fluid that flows through them.For the fluid to provide worthwhile momentum change there must be a significant pressure difference between inlet and outlet. Sources of pressurized gas include previously compressed (and possibly heated) gas. The Turbine used in the Hilton Experimental Reaction Turbine Module F300D is classified as a “single stage, radial flow, reaction turbine”.“Single Stage” means that the expansion of the fluid from the turbine inlet pressure to the exhaust pressure takes place within one stator and in corresponding rotor. “Radial Flow” indicates that fluid enters and leaves the rotor at different radii without significant axial components in the velocity. “Reaction” means that fluid pressure drop (and consequent increase of velocity) takes place in the rotor. The fluid, therefore, passes through the stator at an almost constant pressure. Isentropic Efficiency

Due to irreversibility’s in a real turbine, the actual work transfer will be less than in an ideal machine and consequently the specific enthalpy at exit will be higher than the isentropic enthalpy. Isentropic Efficiency = Shaft power/Isentropic power

The shaft power and the isentropic enthalpy change rate can be found from respectively, Ps = τ.ω = F.r.ω
∆H = m.Cp.∆T
TPy-1/y = Constant

Setup
In a single stage radial reaction turbine the inlet gas is flown from a pump at certain pressure by four nozzles at equal angular distances to drive it. Inlet pressure is noted from a gauge pressure...