210 likes | 818 Views
Derivation of Euler’s pump and turbine equation Velocity triangles for a radial turbine Velocity triangles for an axial turbine Velocity triangles for a radial pump. Absolute specific stagnation energy.
E N D
Derivation of Euler’s pump and turbine equation • Velocity triangles for a radial turbine • Velocity triangles for an axial turbine • Velocity triangles for a radial pump
Absolute specific stagnation energy Starting with Newton 2. law, the absolute acceleration for stationary flow can be derived as: Where: E = Specific stagnation Energy [J/kg] c = Velocity [m/s] f = Friction [N/kg] The absolute specific stagnation energy is constant along a streamline in a frictionless system. Ref. Grunnkurs i Hydrauliske Strømningsmaskiner
The Rotalpy is constant along a streamline Relative specific stagnation energyRotalpy Relative acceleration in a rotating channel can be derived as: Where I = Rotalpy [J/kg] c = Velocity [m/s] f = Friction force [N/kg]
cu cm w c
u1 c1 w1 u2 w2 c2 Velocity Triangles for a Radial Turbine
Velocity triangles for an axial turbine Guidevanes Runnerblades
u2 c2 w2 w1 c1 u1 c w
w1 c1 u1 w2 c1 u2 Velocity Triangles for a Radial Pump w
SVARTISEN u1=75 m/s P = 350 MW H = ? m Q* = 71,5 m3/S D0 = 4,86 m D1 = 4,31m D2 = 2,35 m B0 = 0,28 m n = 333 rpm c1 w1 b1 = 63o hh = 96 % cm1 = 13,9 m/s cu1 = 68 m/s