8.6 A single sided centrifugal compressor is to deliver 14 kg of air per second when operating at a pressure ratio of 4:1 and a speed of 12,000 rpm. The total head inlet conditions may be taken as 288 K and 1.033 kgf/cm?. Assuming a slip factor as 0.9, a power input factor of 1.04 and an isentropic efficiency (based on total head) of 80%, estimate the overall diameter of the impeller. If the Mach number is not to exceed unity at the impeller tip and 50% of the losses are assumed to occur in the impeller, find the minimum possible depth of the diffuser.

مراد جبار فرحان In a gas turbine engine (A, = 2.85 A2, p1 = 1.14 p2, p1 = 100.5 kPa, T, = 11 °C, v1 = 107 m-s1, V2 = 785 m-s", A, = 2.4 m?), calculate the thrust force. %3D %3D ===

Consider an engine with a maximum speed of 7000 rpm. The bore and stroke are 0.1 m, each. For an inlet air temperature of 330 K, determine the intake valve area (assume single valve per cylinder and take k=1.4). O 7.6 cm? O 11.3 cm2 O 4.6 cm2 O 8.3 cm2 O 9.5 cm?

Albert bought a portable device to pump his truck tyres. On the manual, he found out that the device is a single stage, single-acting air compressor. Air delivery for this device is 30 bar at a speed of 1500 rev/min. The atmospheric condition of his location is 87 kPa and 20 ˚C, with a FAD of 0.22 m2 /min. The clearance volume is 4% of the swept volume and the stoke/bore ratio is 1.3/1.Take “n” as 1.3, cp = 1.005 kJ/kg K, cv = 0.718 kJ/kg K Based on pictures below  1 which formula number will be used to evaluate the mass flow rate of air? 2 which formula number will be used to evaluate the delivery volume?

9.2 The inlet stagnation temperature of a centrifugal compressor rotating at 10,000 rpm is 20°C. The inlet flow is axial and the blades are radially tipped at the exit. It is required to produce a stagnation pressure ratio of 2.8 when the total to total effi- ciency is 0.85. It has 19 blades and a mass flow rate of 3.0 kg/s. Through measure- ments, the density of air at the exit of the impeller is found to be 1.5 kg/m³. The width of the blades at the exit is 1 cm. Calculate the following: (a) power required to drive the compressor, (b) diameter of the impeller, and (c) absolute Mach num- ber at the exit. Use Stanitz's equation for the slip coefficient. Ans: 355 kW; 0.694 m; 0.897

A single-sided centrifugal compressor designed with no pre-whirl has the following dimensions and data: Total head/pressure ratio: Speed: Inlet stagnation temperature: Inlet stagnation pressure: 3.8:1 12,000 rpm 293 K 1.03 bar Slip factor: 0.9 Power input factor: Isentropic efficiency: 1.03 0.76 Mass flow rate: 20 kg/s Assume an axial entrance. Calculate the overall diameter of the impeller and the power required to drive the compressor. A. 0.693 m, 3610 kW B. 0.793 m, 3710 kW C. 0.893 m, 3810 kW D. 0.993 m, 3910 kW

A single stage single acting reciprocating air compressor has 0.25 m x 1.75 m runs in 750 rpm is to deliver 0.20m³ free air per second from 101.3 kPa to 355 kPa. Calculate (a) the volume displacement (b) the volumetric efficiency (c) the isothermal work done, compression is at pV =c (d) the isothermal compressor efficiency if the the indicated power of compressor is 40kW