5 A single-acting compressor is required to deliver air at 70 bar from an induction pressure of 1 bar, at the rate of 2.4 m³/min measured at free air conditions of 1.013 bar and 15 °C. The compression is carried out in two stages with an ideal intermediate pressure and complete intercooling. The clearance volume is 3% of the swept volume in each cylinder and the compressor speed is 750 rev/min. The index of compression and re-expansion is 1.25 for both cylinders and the temperature at the end of the induction stroke in each cylinder is 32°C. The mechanical efficiency of the compressor is 85%. Calculate: (i) the indicated power required; (ii) the saving in power over single-stage compression between the same pressures; (iii) the swept volume of each cylinder; (iv) the required power output of the drive motor. 0.000474 m³. 26 75 kW)

You have been asked to help with the low-pressure compressor (LPC) design for a turbofan engine with a bypass ratio of 8.4. The preliminary cycle design calls for the LPC to produce a pressure ratio of 9.4 with the following operating conditions and constraints. .Inlet Conditions TO2 Poz Core Air Mass Flowrate (kg/s) (K) (kPa) 282 24.6 47.0 Design Constraints Maximum Polytropic Efficiency 94.1% Maximum Stage Pr 1.55 Estimate the minimum number of stages required for this LPC. Then assuming the 1st stage of the LPC operates at the maximum allowable pressure ratio, determine the stagnation temperature exiting the 1st stage, and the stage's adiabatic efficiency. Also determine the power (W) required to operate the full LPC (not just 1st stage). Finally, what would be the percent change in the required power if the polytropic efficiency was only 90.0%.

A single acting two-stage air compressor deals with 4 m^3/min of air under atmospheric conditions of 1.013 bar and 15°C with aspced of 250r.p.m. The delivery pressure is 80 bar. Assuming complete inlercooling, find the minimum power required by the compressor and the bore and stroke of the compressor. Assume a pistonspeed of 3 m/s, mechanical efficiency of 75 percent, and volumetric efficiency of 80 percent per stage. Assumethe polytropic index of compression in both the stages to be it = 1.25 and neglect clearance.

QUESTION2 A single-stage double-acting air compressor delivers air at 7.5bar. The pressure and temperature at the end of suction stroke are 1bar and 25°C. It delivers 2.2m3 of free air per minute when the compressor is running at 310rev/min. The clearance volume is 5% of stroke volume. The pressure and temperature of ambient air are 1.03bar and 20°C. Take: index of compression = 1.25 and index of expansion = 1.3. %3D %3D Determine: 2.1 volumetric efficiency of the compressor; 2.2 diameter and stroke of the cylinder if both are equal; 2.3 indicated power of the compressor and Brake power (B.P.) if the mechanical efficiency is 85%. 2.4 Draw the P-V diagram will all the relevant information.

A single stage ,Single acting reciprocating compressor is designed to run at 1000rpm and deliver air at 25 bar in atmospheric conditions of 1.013 bar and 23°C . The compressor is to deliver 6.25m³/min of air.The compressor volume is 3% of the swept volume and the stroke/bore ratio is 1.2 to 1 Calculate (i) The bore and Stroke (ii) The volumetric efficiency of the machine (iii) The indicated power (iv) Isothermal efficiency

Question 2 A two stage, single acting, reciprocating compressor takes in air at a rate of 2 m³/s at a pressure of 1 MPa @ 16°C. The air is compressed to 0.7 MPa while running at 10 rev/s. Compression is ideal and perfect intercooling takes place. The compression process follows pV1.25 = C. Neglect clearance. Calculate: 2.1. Intermediate pressure (0.265 MPa) 2.2. Volume of LP cylinder (20 Liters) 2.3. Volume of HP cylinder (7.5 Liters) 2.4. Total cycle power (42 kW)

A single-acting single-stage reciprocating air compressor running at 1000 rev/min delivers air at 25 bar. For this purpose, the induction and free air condition can be taken as 1.013 bar 15°C, and the FAD as 0.25 m³/min. The clearance volume is 3% of the swept volume and the stroke bore ratio is 1.2/1 with the compressor is assumed to operate polytropically with n = 1.3. Evaluate; (i) bore and stroke; (ii) volumetric efficiency; and (iii) indicated power and isothermal efficiency.

(a) What would be the necessary bore and stroke of a single acting four- cylinder, 350 rpm ammonia compressor working on simple saturation cycle between 35°C condenser and -15°C evaporator temperatures and developing 15 tons refrigeration. Given for the compressor: Ratio of stroke to bore = 1 Volumetric efficiency = 0.7 (b) If the index of compression is 1.15, find the error introduced in calculat- ing the work of compression by assuming the process to be isentropic. Also, find the heat rejected to the compressor-jacket cooling water.

QUESTION 3 A high-pressure axial compressor for a stagnation pressure ratio of 8.5. The mass flow rate of air through the compressor is 16 kg/s and the stagnation conditions at inlet are 200 kPa and 450 K. The polytropic efficiency is 91 %. jet engine rotates at 15,000 rpm with and overall (a) If the mean radius is 0.24 m and this is constant throughout the compressor, calculate the total-to-total isentropic efficiency of the compressor and show that, for the stage loading to be less than 0.4 in all stages, eight stages required. are (b) The compressor is designed with repeating stages and zero inlet swirl. If the inlet axial Mach number is 0.52, calculate the mean flow coefficient and sketch the velocity triangles for one stage. Show that the blade height at exit from the compressor is about 7.8 mm.

: A single stage axial flow compressor with isentropic efficiency of 80%. The comperessor delivers 20 kg/s of air at a rotational speed of 9000 rpm, the stagnation temperature rise is 20 K and the axial velocity is 150 m/s, the mean blade speed is 180 m/s and λ=0.94. The degree of reaction is 50% at mean radius. Take the ambient conditions as 1 bar and 288 K. Find 1) Blade and air angles ( α1, α2, β1, and β2) at mean radius 2) Stage pressure ratio 3) Blade heigh