Air at a stagnation temperature of $15^{\circ} \mathrm{C}$ and stagnation pressure $100 \mathrm{kPa}$ enters an axial compressor with an absolute velocity of $120 \mathrm{~m} / \mathrm{s}$. Inlet guide vanes direct this absolute velocity to the rotor inlet at an angle of $18^{\circ}$ to the axial direction. The rotor turning angle is $27^{\circ}$ and the mean blade speed is $200 \mathrm{~m} / \mathrm{s}$. The axial velocity is assumed constant through the stage. If the mass flow rate is $1 \mathrm{~kg} / \mathrm{s}$, the power required to drive the compressor is (A) $50.5 \mathrm{~kW}$ (B) $40.5 \mathrm{~kW}$ (C) $30.5 \mathrm{~kW}$ (D) $20.5 \mathrm{~kW}$

Question ID - 156258 | SaraNextGen Top Answer Air at a stagnation temperature of $15^{\circ} \mathrm{C}$ and stagnation pressure $100 \mathrm{kPa}$ enters an axial compressor with an absolute velocity of $120 \mathrm{~m} / \mathrm{s}$. Inlet guide vanes direct this absolute velocity to the rotor inlet at an angle of $18^{\circ}$ to the axial direction. The rotor turning angle is $27^{\circ}$ and the mean blade speed is $200 \mathrm{~m} / \mathrm{s}$. The axial velocity is assumed constant through the stage. If the mass flow rate is $1 \mathrm{~kg} / \mathrm{s}$, the power required to drive the compressor is (A) $50.5 \mathrm{~kW}$ (B) $40.5 \mathrm{~kW}$ (C) $30.5 \mathrm{~kW}$ (D) $20.5 \mathrm{~kW}$

(A) $50.5 \mathrm{~kW}$
(B) $40.5 \mathrm{~kW}$
(C) $30.5 \mathrm{~kW}$
(D) $20.5 \mathrm{~kW}$