Thermodynamics Cycles (Piston Question)

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SUMMARY

The discussion centers around the thermodynamic cycles of a 4-cylinder car engine, specifically focusing on the adiabatic compression and expansion processes. Key parameters include a piston diameter of 10 cm, fuel heating value of 2,100 J/g, and fuel consumption of 0.005 g per cycle. The participants aim to calculate pressure, temperature, and volume at various points in the cycle, as well as the power produced at engine speeds of 100 RPM, 500 RPM, and 1000 RPM. The use of polytropic relationships is highlighted as a critical hint for solving the problem.

PREREQUISITES
  • Understanding of thermodynamic cycles and processes
  • Familiarity with P-V diagrams and their significance
  • Knowledge of polytropic relationships in thermodynamics
  • Basic calculations involving pressure, temperature, and volume
NEXT STEPS
  • Research the application of polytropic processes in thermodynamics
  • Learn how to draw and interpret P-V diagrams for different thermodynamic cycles
  • Study the calculations for power output in internal combustion engines
  • Explore the effects of RPM on engine performance and efficiency
USEFUL FOR

Students studying mechanical engineering, automotive engineers, and anyone interested in understanding the thermodynamics of internal combustion engines.

Jtny179
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A 4 cylinder car has 4 Pistons
The cycle is
1-2 : Adiabatic compression of air
- then injects fuel
2-3 : Burn Fuel
3-4 : Adiabatic expansion of gas
4-1 : Exchaust / Replace with fresh air


Homework Statement



Diameter = 10 cm
Minimum depth 1 cm
Maximum depth 10 cm
Heating value of fuel is 2,100 j/g
Each cycle uses 0.005g of fuel
Temp of air = 25 degree celsius
Pressure of air = 101 325 Pa

Homework Equations


Draw P-V Diagram
Calculate P,T,V at all points (1,2,3,4)
Calculate power produced by car at 100 RPM , 500 RPM and 1000 RPM

The Attempt at a Solution

 
Physics news on Phys.org
So basically.. I have the P-V Diagram..
To my understanding you need to calculate power produced by car at 100 RPM to get P,T,V at all points..

Any help? PLEASE
 
Hint: Polytropic relationships
 

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Thank you for your response AM. I appreciate it and will work through the steps.
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