Question

In: Mechanical Engineering

Consider an automobile engine which operates on the ideal Otto cycle. In this engine, air is...

Consider an automobile engine which operates on the ideal Otto cycle. In this engine, air is compressed with a compression ratio of 10. At the beginning of the compression process, air is at 105 kPa and 17oC, and in the combustion process 640 kJ/kg of heat is added to air. Taking into account the variation of specific heats with temperature, determine (a) the pressure and temperature at the end of the heat-addition (combustion) process, (b) the net work output, (c) the thermal efficiency of the engine, and show the cycle on a P-ν diagram.

Solutions

Expert Solution


Related Solutions

Thermodynamics problem: An engine operates on an air-standard Otto cycle. The pressure and temperature of the...
Thermodynamics problem: An engine operates on an air-standard Otto cycle. The pressure and temperature of the isentropic compression 100 kPa and 40 °C, respectively. The pressure at the end of compression is 2.0 MPa and the net work is 87,000 J/mol. Assume ideal air-standard cycle. Determine the following: pressure, volume, and temperature at end of each step. compression ratio. heat input and heat rejected per mol of working fluid. thermal efficiency of the cycle.
A single-cylinder, four stroke research engine operates on Otto cycle. The specification of the engine is...
A single-cylinder, four stroke research engine operates on Otto cycle. The specification of the engine is shown as below:- Displacement volume of the cylinder = 540 cm3 Clearance volume of the cylinder = 60 cm3 Minimum temperature = 200°C Minimum pressure = 200 kPa Net work output = 1000 kJ/kg Sketch the process on a P-V diagram and by using constant specific heat at room temperature, determine: i) the temperature and pressure at each process, ii) the thermal efficiency of...
An ideal Otto engine has a compression ratio of 10 and uses air as the working...
An ideal Otto engine has a compression ratio of 10 and uses air as the working fluid. The state of air at the beginning of the compression process is 100 kPa and 27 0C. The maximum temperature in the cycle is 2100K. (R=0.287 for air) (using variable specific heat) Draw the P-v diagram of the Otto cycle Determine the specific internal energies at the beginning and the end of the compression, Determine the specific internal energies before and after the...
An air-standard Otto cycle operates with a compression ratio of 8. At the start of the...
An air-standard Otto cycle operates with a compression ratio of 8. At the start of the compression stroke, the pressure is 15 psia and the temperature is 80 degrees F. The maximum pressure in the cycle is 550 psia. Find a) the thermal efficiency of the cycle, b) the specific volume at the start of the compression stroke, c) the specific volume at the end of the compression stroke, and d) maximum temperature in the cycle.
An ideal Otto cycle uses air as the working fluid; its state at the beginning of...
An ideal Otto cycle uses air as the working fluid; its state at the beginning of the compression is 120 psia and 60°F, its temperature at the end of the combustion is 1500°F, and its compression ratio is 9. Use constant specific heats at room temperature. Determine the rate of heat addition and rejection for this ideal Otto cycle when it produces 120 hp. The properties of air at room temperature are R = 0.3704 psia·ft3/lbm·R, cp = 0.240 Btu/lbm·R,...
An Otto Cycle engine operation at cold-air standard has a volume of 0.1908 at the beginning...
An Otto Cycle engine operation at cold-air standard has a volume of 0.1908 at the beginning of isentropic compression. If the compression ratio is 12.5, how much heat is released from the fuel per kg of fuel burned if the fuel consumption is 0.02 kg/min? The mean effective pressure is 350kPa.
An ideal four stroke Otto cycle engine has 6 cylinders and a displacement of 4 Liters....
An ideal four stroke Otto cycle engine has 6 cylinders and a displacement of 4 Liters. It has a compression ratio of 8.5:1. If the mean effective pressure is 4000 kPa when operating at 3000 rpm, what will be the indicated power and what is the required heat transfer to the engine from a combusting fuel?
An ideal cold air-standard Otto cycle has a compression ratio of 9.2. At the end of...
An ideal cold air-standard Otto cycle has a compression ratio of 9.2. At the end of the expansion process, the pressure is 110 psi, the temperature is 1020 °R and the specific volume is 3.435 ft3/lbm. The heat rejection from the cycle is 92 BTU/lbm of air. Evaluate specific heat at 100 °F and calculate the following by hand: What is the mean effective pressure (psi)? The correct answer is 231.8 psi. Show every step and calculation with units necessary.to...
An ideal diesel engine uses air as the working fluid and operates with a thermal efficiency...
An ideal diesel engine uses air as the working fluid and operates with a thermal efficiency ?th =0.5 with a rate of heat addition Qin=120 kW. The temperature at the beginning and the end of the addition heat (combustion) are respectively: T2=900 K and T3=2100 K. Assume constant specific heats (Cp and Cv). The air properties at a room temperature T1=293.0 K are: Cp=1.005 kJ/kg.K, Cv=0.718KJ/kg.K, the gas constant of air is R=0.287 kJ/kg.K and the ratio of specific heats...
An air engine is modeled after the ott cycle. Assume ideal gas and air standard cold...
An air engine is modeled after the ott cycle. Assume ideal gas and air standard cold valus for properties. Intake air is at 100kPa and Temperature of 27°C. The compression ration is 8:1. The heat added during ignition is 1740 kJ/kg a) Draw and Label the Pv and Ts diagrams for the Otto cycle b)Find the specific volume at intake state #1 c) Find the temperature at the end of the compression stroke d) Find the Pressure at the end...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT