Search found 121 matches

by Geoff V
Tue Apr 16, 2013 8:03 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

Vamoose I'm very sorry if I appear to be a purveyor of 'subtle opportunistic antagonisms', it was not, and is not my intention to be antagonistic and am dismayed that I appear that way. I am very fortunate to have gained some knowledge from very experienced people on the subject of Hot Air engines a...
by Geoff V
Tue Apr 16, 2013 6:13 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

It doesn't bother me, I am simply being polite to the originator of this thread.

GeoffV
by Geoff V
Tue Apr 16, 2013 6:07 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6123

Re: Gas Simulation

Dave This is the problem, most academic analysis has referred to publications such as Kays and London for heat exchanger performance. Unfortunately, and as has now been realised/accepted, all the heat transfer data is for steady fluid flow and consequently appears to be very wide of the mark when ap...
by Geoff V
Tue Apr 16, 2013 5:46 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

Derwood Apologies for the diversion. Vamoose The Thermomechanical Generator is simply a very short stroke Beta Stirling cycle engine, short stroke because the displacer is held by a flat spring which limits its travel and very similar in operation to the Free Piston Beta engines developed by SunPowe...
by Geoff V
Mon Apr 15, 2013 11:02 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6123

Re: Gas Simulation

Dave I have emailed this link to Allan for his suggestions as he has travelled this path, probably more comprehensively than any other academic to date. It is likely he will decline to offer advice as it is essentially impossible to measure many of the inputs you need and therefore it will be based ...
by Geoff V
Mon Apr 15, 2013 10:25 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

could it not be just as plausible that the engine ceased working because the speed of sound in helium is 3 x that of air? Having discussed this matter at length with a very close friend, Allan Organ, and with reference to the article from the University of Gent, I do not believe there is any signif...
by Geoff V
Sun Apr 14, 2013 11:29 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

Gentlemen I must reiterate my dislike of the term 'Lamina Flow', these engines function due to a Thermal Lag, which is also present in the Stirling cycle but detrimental to the performance, and the gas flow within the engine is certainly turbulent, NOT lamina. The Thermal Lag can be demonstrated, as...
by Geoff V
Mon Apr 08, 2013 3:35 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: one cylinder 2 piston beta configuration
Replies: 8
Views: 4036

Re: one cylinder 2 piston beta configuration

Fullofhotair You are quite correct when you suggest that the heater exhaust should be as near ambient temperature as possible. Stacking engines on top of each other is not the most elegant way to achieve this as the coolest running engine would see so little heat that the efficiency would be very ve...
by Geoff V
Sun Apr 07, 2013 11:37 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Big Beta Stirling 1kw, 100degC to 400degC
Replies: 113
Views: 44855

Re: Big Beta Stirling 1kw, 100degC to 400degC

Zhivko The chart I published shows heat transfer from a solid to air, not a solid to air to a solid! For heat transfer to take place there must be a temperature difference, so by definition the fins will be cooler than the temperature of the air by conduction alone. There will be some radiant heatin...
by Geoff V
Sun Apr 07, 2013 9:44 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Big Beta Stirling 1kw, 100degC to 400degC
Replies: 113
Views: 44855

Re: Big Beta Stirling 1kw, 100degC to 400degC

Zhivko

How do you intend to join the fins to the outer casing of the heater? if they are not welded to the case, there will be very little heat transfer.

GeoffV
by Geoff V
Fri Mar 22, 2013 12:45 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Regenerator and cylinders in a beta stirling engine
Replies: 17
Views: 8518

Re: Regenerator and cylinders in a beta stirling engine

RenewableEnergy Regarding your proposed design, I must ask why you favour the three gear Rhombic as depicted in the video. Most of the noise generated in a Rhombic is from the syncronizing gears and adding a third gear will simply increase the noise and the friction, I see no point. I also fail to u...
by Geoff V
Sun Mar 17, 2013 2:18 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Dean Kamen’s Stirling Generator
Replies: 2
Views: 4303

Re: Dean Kamen’s Stirling Generator

Jim Thank you for posting the links to these development projects. Unfortunately nothing has been seen or heard of the Stirling Cycle engines since being published in, 2008 for the Red Ferret report and 2009 for the Kamen press release. It begs the question " are these projects still active", my gue...
by Geoff V
Mon Mar 11, 2013 11:10 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

Derwood For the purpose of measurement and comparison, the capacity of your TLE is, bore area x stroke (swept volume), Hot air engine derivitives are normally categorised this way with a few exceptions such as, the vee twin alpha. Because the working volume in a vee twin alpha cannot be equal to the...
by Geoff V
Fri Mar 01, 2013 12:34 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

Derwood I believe I now understand why your engine is so dependant on choke size, FRICTION, if I may expand my thoughts. From my test results, the choke produces a more 'peaky' curve and slightly less power than the tubular cooler head and changing the choke size in small increments demonstrates tha...
by Geoff V
Thu Feb 28, 2013 10:42 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53733

Re: large lamina flow build

Derwood

Apologies for the distraction.

Vamoose

Thanks for the link, it works well.

GeoffV