Pressure and volume at each stage Carnot engine

Click For Summary
SUMMARY

The discussion focuses on calculating the pressure and volume at each stage of a Carnot engine cycle using 0.05 kg of air as the working substance. The temperature limits are set at 300K and 940K, with a maximum pressure of 8400KPa and heat added per cycle of 4.2KJ. Key equations mentioned include the work done during isothermal expansions, W=m*R*T*ln(v2/v1), and the relationship for adiabatic expansions, T*V^(r-1)=T*v^(r-1). Participants emphasize starting calculations from the maximum pressure and temperature to determine the state variables at critical points in the cycle.

PREREQUISITES
  • Understanding of Carnot engine principles
  • Familiarity with thermodynamic equations for isothermal and adiabatic processes
  • Knowledge of specific heat ratios, specifically r(gamma)=1.4
  • Basic skills in manipulating state equations for gases
NEXT STEPS
  • Calculate pressure and volume at the maximum temperature of 940K using the ideal gas law
  • Explore the implications of the Carnot efficiency formula on engine performance
  • Learn about the impact of varying the working substance on Carnot engine efficiency
  • Investigate the effects of different heat addition methods on the cycle's performance
USEFUL FOR

Students and professionals in thermodynamics, mechanical engineers, and anyone studying the efficiency of heat engines, particularly those interested in Carnot cycles and their applications.

mfm
Messages
1
Reaction score
0
A carnot engine uses 0.05kg of air as the working substance. The temperature limits of the cycle are 300K and 940K, the maximum pressure is 8400KPa, and the heat added per cycle is 4.2KJ. Determine the pressure and volume at each state of the cycle.

r(gamma)=1.4 and R=0.287KJ/Kg Kim pretty sure the state equations are
W=m*R*T*ln(v2/v1) for the isothermal expansions and
T*V^(r-1)=T*v^(r-1) for the adiabatic expansions,

but I have no idea how to use them, any help would greatley help.
 
Physics news on Phys.org
Welcome to Physics Forums :smile:

Use the information about the maximum temperature and pressure to get P and V at one of the "corner points" in the cycle. This is a good starting point from which you can figure out how things change as one goes around the cycle.
 

Similar threads

Replies
14
Views
2K
  • · Replies 14 ·
Replies
14
Views
9K
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K