• Support PF! Buy your school textbooks, materials and every day products via PF Here!

Finding the work done by a Stirling Cycle

1. Given the following p-V diagram of an ideal Stirling Cycle, determine the theoretical values of W12, Q12, W34 and Q34 in terms of T1, T2, V1, V2, n (the number of moles) and R (the universal gas constant). Determine the total theoretical p-V work W12341 for the full cycle.


2. dU = dQ-Pdv


3. I've only just started thermodynamics recently, so my grasp on it is still very weak. I've tried finding W12 using W = -∫pdV but I'm not really sure how that gives me theoretical work. I think I'm supposed to end up with some sort of numerical answer for the final part to compare it with an actual p-V work value and find the efficiency of the Stirling Engine.
de424315a5395941d2365d8e794de16e.png
 

kuruman

Science Advisor
Homework Helper
Insights Author
Gold Member
8,092
1,741
I've tried finding W12 using W = -∫pdV but I'm not really sure how that gives me theoretical work.
When you write W12 = - ∫p dV, both p and V are changing from 1 to 2. How about replacing p with something else using the ideal gas law?
 

Nidum

Science Advisor
Gold Member
2,990
845
The working fluid in an ideal Stirling cycle engine goes through four processes :

Compression at constant temperature .
Heat addition at constant volume .
Expansion at constant temperature .
Heat removal at constant volume .

Can you identify the four processes on your diagrams ?

What formulas apply to each process ?

Reading material :

Stirling Cycle
Constant temperature process
Constant volume process
 
Last edited:
The working fluid in an ideal Stirling cycle engine goes through four processes :

Compression at constant temperature .
Heat addition at constant volume .
Expansion at constant temperature .
Heat removal at constant volume .

Can you identify the four processes on your diagrams ?

What formulas apply to each process ?

Reading material :

Stirling Cycle
Constant temperature process
Constant volume process
Oh thank you! Your response was very illuminating. I hope you don't mind but I'd just like to check I've got this right:
For Isothermal Expansion : W = nRTln[Vf/Vi]
For Isothermal Compression: W = - nRTln[Vf/Vi]
For Heat Addition: Q = nCvΔT
For Heat Removal: Q = - nCvΔT
 

Want to reply to this thread?

"Finding the work done by a Stirling Cycle" You must log in or register to reply here.

Related Threads for: Finding the work done by a Stirling Cycle

Replies
1
Views
3K
Replies
2
Views
4K
Replies
7
Views
3K
Replies
4
Views
593

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top