Question

9. A constant-area duct connected to a C-D nozzle with 1,687. The nozzle is fed by a large compress-air tank with pressure of 700 kPa and temperature of 540 K. The flow is shockless everywhere and is supersonic at the nozzle exit. Between section 1 and 2, heat added into the duct at a rate of 100.4 kJ/(kg of air). Assuming frictionless flow and ideal gas. Find these properties at section 2: M2. P2.T2 and Poz. 1, nozzle exit Po 700kP To 540K Find: M2.P2,T2 and po2 6 100.4 kj/kg dm

Answer 1

Given that P_0 = 700 kpa T_o = 540 K T_1 = r T_0 = 1.4 (540) = 756 k A_2/A_1 = 1.687 therefore Q = A_1 A_2/squareroot A^2_1 - A^2_2 squareroot 2g (Delta h) h_1 + dQ/dH = h_2 + dw/dH dQ/dH = h_2 - h_1 100.4 = c_p (T_2 - T_1) 100.4 = 1.005 (T_2 - 756) T_2 = 855.9 k Delta h = P_1 - P_2/rho g Here volume is constant \r\n P_1/P_2 = T_1/T_2 P_2 = 700 times 855.9/756 P_2 = 700 times 855.9/756 P_2 = 792.5 Kpa Delta h = p_1 - p_2/rho g = 7.85 Q = A_1 A_1/squareroot A^2_1 - A^2_2 squareroot 2g Delta h = 7.35 m^dot = rho Q = > M_2 = 8.8 kg/sec