Stirlingengineforum.com

I'm a longtime alpha fanboy who favors basic Rider with upgrades. The main issue with the Rider is the entire notion of heating the working cylinder which is why I find gammas interesting. Here's my spin on alpha advantages: (1) with ideal phasing (whatever that entails) a typical 2:1 compression sl...

Taking this sample problem: T1=400°K T2=300°K efficiency = 1-300/400 = 1/4 = 25% https://www.toppr.com/ask/question/the-source-and-sink-temperatures-of-a-carnot-engine-are-400k-and-300-k-respectively/ That is fine. I agree with it! The question is 25% of what? 25% of T1, all the heat down to absolu...

Let's start with thermo notation: Wneg, Wpos, Wnet, Win, Wout... are common work values where the neg (etc) are typical subscript. Q is quantity of energy "flow" and usually qualified, but even something as simple as Q1, Qh, Qhigh does not denote direction of flow (in vs out) which is left...

How is Qhz the "maximum"? Qhz is not the "heat" supplied. Qhz is Qcz , the pre-existing environment in thermal equilibrium before any heat is supplied, added or taken in by the engine. Plus the few additional joules actually supplied. As you say: "the cycle starts at Qcz, (...

I'm so used to the "perfect" Stirling regeneration that it blinded me to the trick for quite some time. I don't think many people in the world would pick it up. Do I get my honorary PHD in MESE now! Mechanical Engineering Stirling Engines. LOL Degree issued, but here's some more stuff to ...

Indeed, eff = (Wpos-Wneg)/Wpos is the best approach for compression cycles since this is easy to quantify and eliminates Q vs T issue/s. When a cycle is non-compression, then Q=W is the only option.

Even using Q1 to unify quantity of input with Thigh is far from bulletproof.

Here's another 300-1050k Otto cycle, but where Vr = 1.5 and 'wider' isochors allow more regen. D Otto 300-1050k.png Due to paltry Vr, this Otto cycle has base eff = .15 base sink = 300-900k base source = 350-1050k however, isochors overlap 350-900k thereby potential regen = 550k potential sink = 50k...

Awesome job Fool, you're hired !!! Did you catch my blunder ? back story : I don't waste much time trying to beat Carnot. This Otto cycle evolved while gaming low volume Otto cycles with Rocky Horror sound track playing in background (via my youtube feed due to upcoming 50 yr anniversary). This insp...

I tend towards common “Urieli speak” notation, but always add r to PVT whereby Pr = pressure ratio Vr = volume ratio Tr = temperature ratio I’m also going to use eff = efficiency to save pecking. OK, class, let’s begin… Ideal Otto eff can be derived via a needless long method for any Doubting Thomas...

I'm a doof and missed the lower eff. of the Stirling. Ok so how do you regen closed cycle Otto? I'm working on it. I like the LTD eff. approaching 1.00, how does it get around Carnot? Does it have to do with near Cv operation? You nailed it again !!! It's the "one-one" (300k-Vmin) approac...

We have previously determined that buffer pressure has no effect on efficiency, and that charge pressure has little to no effect. So what parameters would have to be changed to reach "super-carnot" (thanks Matt) efficiency? IOW, does the atmosphere have to be absolute zero? So in that cas...

Within the crazy 300-1050k cycle per graphics (1) ideal Stirling has Carnot = .71 (2) ideal Otto without regen has Carnot = .25 (3) ideal Otto with regen has Carnot = .85 Yikes, another botched post which should be (1) ideal Stirling has Carnot win = .71 eff (2) ideal Otto without regen has Carnot ...

So why the Otto pitch if Stirling prevails? Within the crazy 300-1050k cycle per graphics (1) ideal Stirling has Carnot = .71 (2) ideal Otto without regen has Carnot = .25 (3) ideal Otto with regen has Carnot = .85 The common ICE cycles we're used to (Otto and Diesel) can't use regen due to PVT val...

Exactly 200 years after Carnot released "Reflections", it appears that I've (finally) sunk the widely held Carnot theorem with a simple GRAPHIC proof that will cause major controversy among academics (see forum link): http://www.stirlingengineforum.com/viewtopic.php?p=22072#p22072 Is this ...

Sorry for the extreme values, but Geogebra app doesn't allow scale changes. Basic scheme is low volume ratio Otto where (1) 2:1 volume ratio is still common Stirling ratio (2) "zero point" isobar to allow 'buffer' compression (3) both charge AND buffer pressure are above ambient Despite t...