Advice on number of regenerator tubes.

[H..Deep]

Just Completed some calculations on beta stirling. I need help on number of regenerator tubes reuired for the purpose.
The engine is a beta type stirling engine with rhombic drive.
Vse = 118cm^3
Vsc = 103 cm^3
Phase angle = 108
Pressure applied = 75 psi/517kpa
Th = 576K (Kerosene burner)
Tc = 303K
I know the dislacement ratio is not optimum but this is due to geometry of rhombic drive.
Just finished schmidt analysis and got a very awkward looking pv plot.Rechecked the calculations many times but always getting the same result.
Can anyone interpret the pv plot.
Any help will be appriciated.

[Ian S C]

I presume these are the tubes for the hot end heat exchanger, I'm sorry I can't help much as I have not got this far into these engines. I am at the moment building (slowly) a Rhombic drive engine, it will be an air cooled, atmospheric pressure one. It may end up having the power cylinder sleeved down.
Ian S C

[H..Deep]

Thankyou for the generous response.Yes these are for the hot end heat exchanger and will also form cooler space. For the rhombic drive i followed dimensionless analysis by peace labs. Can you please explain" having the power cylinder sleeved down".
At crank angle 0 the displacer is at top and piston is at bottom.

[Aviator168]

I think you mean heating tubes. Since many of us here are not filling the engine with high thermal conductivity fluid, the internal heating area and material of heat exchange are two of the variable we can play with. Has anyone actually calculate the amount of heat can be injected into and remove from the engine before building?

[Ian S C]

The reason that I may need to sleeve the power cylinder is to get the ratio nearer to the 1.5 : 1 ratio, the ratio of the stroke is fairly similar for both components.
Ian S C