Diesel combustion and gas laws

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SUMMARY

The discussion focuses on the principles of diesel combustion and the relevant gas laws governing diesel engines. Specifically, it addresses the compression ratio of 17:1 in diesel engines and the expansion of air volume by approximately five times during combustion. Key calculations involve determining the BTUs released during the combustion stroke, which is influenced by the specific heat of combustion of diesel fuel. The conversation highlights the importance of understanding the relationship between fuel volume and air volume in the combustion chamber.

PREREQUISITES
  • Understanding of diesel engine mechanics and operation
  • Familiarity with the ideal gas law (PV=nRT)
  • Knowledge of BTU calculations and specific heat of combustion
  • Basic principles of thermodynamics related to combustion
NEXT STEPS
  • Research the specific heat of combustion for diesel fuel
  • Learn about the ideal gas law and its applications in combustion analysis
  • Explore BTU calculations in the context of diesel engine performance
  • Investigate the effects of fuel-to-air ratios on combustion efficiency
USEFUL FOR

Engineers, automotive technicians, and students studying mechanical engineering or thermodynamics, particularly those focused on diesel engine design and performance optimization.

Denis46
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Hi all, new guy here. I am trying to understand the laws that govern a diesel motor. I know it compresses air at about 17 to 1 to ignite the fuel and I think that fuel will expand the air in the chamber at about 5 times the volume consistently (from tdc to end of stroke). I am trying to figure how many BTUs is used to heat the combustion stroke. Also, is the volume of liquid diesel added to the air important to the volume of the chamber (apart from igniting and expanding the air). I have tried to understand this with V1*P1/T1=V2*P2/T2, including using Kelvin and Pa, but could not make the numbers work.

I hope I have phrased this properly.

This is the first of a few questions to come

Thanks in advance
Denis D.
 
Science news on Phys.org
Hi Denis,

Welcome to PF. The amount of BTU's released would be equal to the specific heat of combustion of the diesel fuel times the amount of fuel, but I don't know what either of those two numbers are.
 

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