Test Rig
In order to allow comparison between the dynamic model and our real Stirling engine a testing method is required. Ideally we would like to be able to measure; temperature input, engine speed and torque output. From here we could use known theoretical calculations to determine the engines efficiency and power output.
Once the engine is operational our aims are to further asses the Stirling engines capabilities. Our main areas of experimental interest are:
During the design stage of the engine it was a group decision to manufacture two displacers with variations in their geometry and use within the Stirling engine. The result of this gives two differing engine set-ups.
Set-up one: The displacer with the smaller diameter is to be used within the regenerator tube. This is the set up shown in the Pro-Engineer model and assembly video.
Once the engine is operational our aims are to further asses the Stirling engines capabilities. Our main areas of experimental interest are:
- Test the engine at different operational temperatures. These should coincide with the values used to asses the different outcomes in the dynamic model with varying hot cap temperatures. By doing this direct comparisons between the engine and dynamic model could be made.
- Vary the regenerator material. Since it is difficult to know the efficiency of regenerative material experimental tests are the best way to determine which materials work, and which do not.
- Test the engine using both of the set-ups designed. The two engine set-ups are described below.
During the design stage of the engine it was a group decision to manufacture two displacers with variations in their geometry and use within the Stirling engine. The result of this gives two differing engine set-ups.
Set-up one: The displacer with the smaller diameter is to be used within the regenerator tube. This is the set up shown in the Pro-Engineer model and assembly video.
Set-up one
Set-up two: The larger displacer piston is installed by removing the regenerator tube. This set up does not allow the regenerator to be housed along the fluid flow path. Instead regenerative material can be installed within the displacer piston itself. This will obviously give different output results of the engine. These outputs however are difficult to guess and can only be determined by running experimental tests.
Set-up two
An Aside
As a side note: Since the completion of our components was delayed by three weeks the overal time left to construct, test and asses the engine was depleted. When this was coupled with the horror that the engine was not functioning our focus lay on only achieving one engine set-up this year. Since the parts were completed for engine setup and the larger displacer was not manufactured we could only attempt to run the engine as set up one shown.
The larger displacer was not manufatured by the time of the design project deadline and so setup two was never tested.
The larger displacer was not manufatured by the time of the design project deadline and so setup two was never tested.
