Transient Heat Transfer Gods?

[a.mlw.walker]

Hi

Anyone with experience with transient heat transfer please can you help me.

I have attached an image that is a simple stirling engine schematic. One half is essentially a pipe that is heated from one end and kept at room temperature at the other end. Inside it is a displacer that is not sealed against the walls of the pipe.

The displacer is attached to a piston, in the other part of the chamber, that IS sealed against th walls.

I know all the geometry of the system.

My problem is doing the transient heat transfer to the gas inside generated by heating one end of the pipe.

When the gas is heated, the average system temperature rises. The increases the average system pressure. this pushes the piston back, which inturn moves the displacer a little, adjusting the volume of gas a the hot end of the pipe. This in turn affects the system pressure and temperature etc etc.

Can anyone help me approach this transient problem. I just can't find a successful way to model this over time, there are so many things changing, all because I put some heat in!

Thanks

 

[Yeti08]

To start with, try out the Schmidt analysis, but keep in mind that you have a gamma type engine when using phase angles. If you need more accurate/complex models there are plenty of books on the subject - Allan Organ has a few decent ones.

 

[oswaler]

for reaching out for help with your transient heat transfer problem. It sounds like you have a complex and interesting system with your Stirling engine. Transient heat transfer can definitely be a challenging problem to solve, especially when there are multiple factors at play like in your system.

One approach you could consider is using a numerical simulation method, such as finite element analysis or finite difference methods, to model the heat transfer over time. These methods allow you to break down your system into smaller elements or cells and solve for the temperature and pressure changes at each time step. This can give you a more accurate understanding of how the heat is transferred and how it affects the system as a whole.

Another approach could be to experimentally measure the temperature and pressure changes in your system over time and use that data to validate your numerical simulations. This can help you fine-tune your model and make it more accurate.

It's also important to consider all the factors that could affect the heat transfer in your system, such as convection, radiation, and conduction. Make sure to account for these in your model and consider their impact on the overall system.

Overall, solving transient heat transfer problems can be a complex and iterative process, but with careful consideration and a thorough understanding of your system, you can successfully model and predict the behavior of your Stirling engine. Best of luck with your project!