Question

The compression ratio of an engine is 10 and the temperature and pressure at the start...

The compression ratio of an engine is 10 and the temperature and pressure at the start of compression is 370 Celcius degree and 1 bar. The compression and expansion processes are both isentropic and the heat rejected at exhaust at constant volume. The amount of heat added during the cycle is 3000 kJ/kg.
Determine the mean effective pressure and thermal efficiency of the cycle if the maximum pressure is limited to 70 bar and heat added at both constant volume and constant pressure.
Assume that the charge has the same physical properties as that of air.

Note: k=1.4, Cv=0.717 kJ/kgK, R=0.287 kJ/kgK
75 minutes,

Engineering   Mechanical-Engineering   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

To find Q(out) T5 is found out

From Q(out) thermal efficiency is found out

From thermal efficiency Work is found out and then P(mean) can be computed.

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
An inventor proposes a four-stroke cycle running on helium. The engine has a compression ratio of...
An inventor proposes a four-stroke cycle running on helium. The engine has a compression ratio of 8 and maximum operating temperature of 1,500 K. The atmospheric conditions are temperature of 300 K and pressure of 100 kPa. The processes can be approximated as below: 1- 2 isentropic compression 2- 3 constant volume heat addition 3- 4 isentropic expansion 4- 1 constant pressure heat removal a. Plot P-v and T-s diagrams for this cycle. b. Determine state conditions at the end...
An ideal Otto cycle has a compression ratio of 7. At the beginning of the compression...
An ideal Otto cycle has a compression ratio of 7. At the beginning of the compression process, P1 = 90 kPa, T1 = 27°C, and V1 = 0.004 m3. The maximum cycle temperature is 1147°C. For each repetition of the cycle, calculate the heat rejection and the net work production. Also, calculate the thermal efficiency and mean effective pressure for this cycle. Use constant specific heats at room temperature. The properties of air at room temperature are cp = 1.005...
A Diesel cycle has a compression ratio of 12 and cut-off ratio of 2. At the...
A Diesel cycle has a compression ratio of 12 and cut-off ratio of 2. At the beginning of the isentropic-compression process, the pressure and temperature are 100 kPa and 35°C (308 K), respectively. During the constant-pressure process, heat is added to the working fluid from a reservoir at a temperature of 1760°C (2033 K). During the constant volume process, heat is rejected to the environment, which is at 30°C (303 K) and 100kPa. For the air involved, it may be...
In an ideal standard dual cycle, the pressure and temperature at the beginning of compression are...
In an ideal standard dual cycle, the pressure and temperature at the beginning of compression are 1 bar and 47°C, respectively. The heat supplied in the cycle is 1250kJ/kg, two third of this heat is being added at constant volume and the remaining heat is added at constant pressure. If the compression ratio is 16, determine 1)the maximum temperature in the cycle. 2)the thermal efficiency of the cycle. 3)the mean effective pressure.
10) An air-standard Otto cycle has a compression ratio of 9. At the beginning of the...
10) An air-standard Otto cycle has a compression ratio of 9. At the beginning of the compression process, the temperature is 20°C, and the pressure is 100 kPa. The heat added is 500 kJ/kg. Determine the cycle efficiency, work output, and the heat rejected. 11)An air-standard Otto cycle operates with a minimum temperature of 300 K and a maximum temperature of 1700 K. The compression ratio of the cycle is 7. At the beginning of the compression process, the pressure...
1a. An air-standard cycle consists of the following processes: isentropic compression from 15 ?C, 1.01 bar...
1a. An air-standard cycle consists of the following processes: isentropic compression from 15 ?C, 1.01 bar through a compression ratio of 5:1; heat addition at constant volume of 2600 kJ/kg; isentropic expansion to the initial volume; heat rejection at constant volume. Sketch the cycle on p-v and T-s diagrams, and calculate its ideal efficiency, mean effective pressure and peak pressure. Answers(0.475, 18.9 bar, 73.0 bar) b. The cycle is problem (a) is modified so that the heat is added (a)...
Pressure and temperature at the beginning of compression of compression of an air-standard (R=287 J/kgK, gamma=...
Pressure and temperature at the beginning of compression of compression of an air-standard (R=287 J/kgK, gamma= cp/cv=1.4). Diesel cycle are 107kPa and 280K, respectively. At the end of the heat addition, the pressure is 11MPa and the temperature is 2040K. a) Determine the cut off ratio:
1) An air-standard Otto cycle has a compression ratio of 9. At the beginning of the...
1) An air-standard Otto cycle has a compression ratio of 9. At the beginning of the compression process, the temperature is 20°C, and the pressure is 100 kPa. The heat added is 500 kJ/kg. Determine the cycle efficiency, work output, and the heat rejected 2) An air-standard Otto cycle operates with a minimum temperature of 300 K and a maximum temperature of 1700 K. The compression ratio of the cycle is 7. At the beginning of the compression process, the...
An automobile uses a four-cylinder engine. Within each cylinder of the engine, the processes can be...
An automobile uses a four-cylinder engine. Within each cylinder of the engine, the processes can be modeled as an air-standard Otto cycle. At the beginning of the compression process, the cylinder volume is .559 L. The temperature and pressure are 330K and 1.5 bar, respectively. In the cycle, the maximum temperature is 2200K when the engine operates at 3000 RPM. If the engine compression ratio is 9.5, determine (a)  the air mass flow rate to the engine in g/s. (b) the...
A four-cylinder, four-stroke engine is built into an automobile. Within each cylinder of the engine, the...
A four-cylinder, four-stroke engine is built into an automobile. Within each cylinder of the engine, the processes can be modeled as an air-standard Otto cycle. At the beginning of the compression process, the cylinder volume is .559 L. The temperature and pressure are 330 K and 1.5 bar, respectively. In the cycle, the maximum temperature is 2200 K when the engine operates at 3000 RPM. (4-stroke engine, 2 rotations per cycle, MW of air = 28.97 kg/kmol) If the engine...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT