Velocity of the steam leaving the nozzle is 1200 m/s. The nozzle angle is 20° and the mean blade velocity is 500 m/s. The inlet and outlet angles of blades are equal. The mass of the steam flowing through the turbine per second is 0.4 kg. Considering the blades to be frictionless determine the Power Developed.

Correct Answer: 251.30 kW
Cbl = 500 m/s, C1 = 1200 m/s, α = 20°, ṁ = 0.4 kg/sec, θ = Ф Steps of Construction – Select a suitable scale and draw a line LM to represent Cbl (=500 m/s). At point M make angle of 20° (α) and cut length MS to represent the velocity 1200 m/s. Produce L to meet the perpendicular drawn from S at P. Thus inlet triangle is completed. By measurement: θ = 33°, Cr1 = 749.91 m/s θ = Ф = 33° Cr2 = Cr1 = 749.91 m/s At point L, make an angle of 33° (Ф) and cut the length LN to represent Cr2(= 749.91 m/s). Join MN. Produce M to meet the perpendicular drawn from N at Q. Thus outlet triangle is completed. By measurement: Cw1 = 1127.6 m/s and Cw2 = 128.9 m/s Power Developed = ṁ (Cw1 + Cw2) Cbl = 0.4(1127.6 + 128.9)500 = 251300 W or 251.3 kW