A vertical shaft Kaplan turbine operating under a head of 9.8 mhas a runner diameter of 9.3 m. At the maximum optimum point, theturbine runs at 51.7 rpm and develops 45,000 kW power discharging535 m 3 /s water. Determine the values of unit speed, unitdischarge, unit power and specific speed of the turbine. If thecritical value of cavitation coefficient for the runner is 0.95,determine the location of the runner with respect to the tail racewater level. The atmospheric and saturated vapour pressures may betaken as 9.8 m and 2.5 m respectively. Will the runner be locatedbelow or above the tail race water level? [ 59 . 153 ? u N , 989 .1 ? u Q , 96 . 16 ? u P , 51 . 632 ? s N , 01 . 2 ? ? s H , below]2. Calculate the diameter, speed and specific speed of a propellerturbine runner to develop 6,250 kW under a head of 5 m, given thatthe speed ratio Ku based on the outer diameter is 2.10, flow ratio?=0.65. Assume the diameter of the boss (hub) is 0.35 times theexternal diameter of the runner and overall efficiency is 85 %. [D= 5.81 m, N = 68.37 rpm, Ns= 722.93] 3. A hydraulic turbinedevelops 130 kW at 230 rpm under a head of 16 m. Determine thescale ratio and the speed of a similar machine which will generate660 kW when working under a head of 25 m. [Scale ratio (D2/D1) =1.612, N2 = 178.35 rpm]
