Finding the work done by a Stirling Cycle

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The discussion focuses on calculating the work done and heat transfer in an ideal Stirling Cycle using a p-V diagram. Key points include determining theoretical values for work (W12, W34) and heat (Q12, Q34) in terms of temperature, volume, moles, and the universal gas constant. Participants emphasize using the ideal gas law to replace pressure in the work integral and identify the four processes of the cycle: isothermal compression, heat addition, isothermal expansion, and heat removal. Formulas for each process are confirmed, including those for work and heat transfer. The conversation highlights the importance of understanding these concepts for calculating the efficiency of the Stirling Engine.
TheBigDig
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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-Pdv3. 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.
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TheBigDig said:
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?
 
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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
 
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Nidum said:
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
 
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