Here we go again! I agree that alphas, betas and gammas plus the acoustic version all the conform to my criteria for a Stirling engine (IÃ‚Â’ll stretch a point for the acoustic in which the piston takes the form of a diaphragm); also that there can be LTD and HTD versions of any of them. The rotary I am not so sure about Ã‚Â– it depends on the nature of the cycle. If the charge gas cycle takes the reversing, unsteady state form normally provided by reciprocating motion, then I will go along with it being a Stirling cycle Ã‚Â– if not, not. Where I disagree is on the role of the regenerator. All the formats you mention have, and crucially depend on, a regenerator. Without it, the laws of thermodynamics tell you loud and clear that in the Stirling cycle as globally understood you will get little or no net power output and horrendously low efficiency. That is why the hot air engine was never a commercial item competing with the steam engine until Stirling gave it a new cycle by inventing the regenerator. If you think you have a heat engine that produces useful power at reasonable efficiency without a regenerator then you do not have a Stirling engine.
Why go on about this at great length? For the simple reason that if you want investment in your engine for developing countries, and have found a solution that works, it is counterproductive to call it a better Stirling engine if, in fact, it is something different. And the reason for that is also simple: investors are not stupid Ã‚Â– they can easily look up the dismal history of 70 years of attempts to commercialise the Stirling, and will ask Ã‚Â– so whatÃ‚Â’s different? Their engineering advisers will quickly distinguish between a hot air engine (no pun intended) that is a Stirling without a regenerator and much worse than the Stirling, and a completely new idea which might actually do the job and be investable. I want to avoid failure and disillusion on the part of enthusiasts for developing world solutions. On this issue, I was interested to note that your investable package included plans for a production facility: no investor I know would consider such issues unless and until there was at the very least a working prototype.
On your third paragraph, the answer is simple. Assuming you have no mechanical, thermodynamic or gas friction losses, you would indeed be describing the ideal Stirling cycle, but for one point. That point is that your compression ratio is ratio is infinite, which is what allows you to eliminate the regenerator. But, first, you no longer have a Stirling cycle, and, second, the ideal Stirling cycle cannot be achieved Ã‚Â– we can only go as far as the inevitable losses and cost constraints on design etc will allow us. So, have you got a heat engine with a different cycle (not a Stirling) that does the job that everyone agrees needs doing? I cannot tell from what you have provided, and I understand that confidentiality may prevent you from disclosing more. Have you built a prototype Ã‚Â– even a small one? If so, we can all look forward to publication of the results of independent tests. If not, it would help all of us looking for solutions if you could do so, but please, do not further confuse discussion by calling it a Stirling engine if it is not a Stirling engine!