Question

Euler equation of turbine giving energy transfer per unit mass E₀ (where U, V_w, V_r  and V represent the peripheral, whirl, relative and absolute velocities respectively. Suffix 1 and 2 refer to the turbine inlet and outlet respectively) is given by                     

a. E₀ = U₁V_w1 – U₂ V_w2

b. E₀ = U₁V_r1 – U₂ V_r2

c. E₀ = U₁V₁ – U₂ V₂

d. E₀ = V₁V_w1 – V₂ V_w2