Search found 121 matches

by Geoff V
Tue Jan 01, 2013 11:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Big Beta Stirling 1kw, 100degC to 400degC
Replies: 113
Views: 59524

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

Zhivko Welcome back, hope you had a good Christmas break. From your test results and with the new dimensions, I would expect the engine to run OK if the friction losses are low enough. Having the engine mounted with the cylinder horizontal will not help, as the displacer and piston mass will have to...
by Geoff V
Tue Jan 01, 2013 8:49 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Solar Parabolic Stirling dish
Replies: 9
Views: 6861

Re: Solar Parabolic Stirling dish

I had heard that a company like the one in the videos, maybe the same company, had stopped trading because of the noise of the SE's, if it is the same, then I'm not surprised, the engine noise is not only horrendous, but quite unnecessary. It's time they engaged a proper design engineer before all S...
by Geoff V
Sat Dec 29, 2012 11:55 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: v8 Alpha stirling generator concept
Replies: 19
Views: 12435

Re: v8 Alpha stirling generator concept

John

Have a search for Andy Ross Stirling engines, there's a free download of his book available, it's a good read.

The ICE, with all its faults, is still an amazing device, until fuel supplies become intermittant!

GeoffV
by Geoff V
Sat Dec 29, 2012 1:23 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Regenerator material option
Replies: 9
Views: 8118

Re: Regenerator material option

Vamoose I think the mesh you've found is probably too coarse, we've been using 80 to the inch (FF 30%) yet the early Whispergen regenerators used approx 150 to the inch (FF 40%), unless the mesh is very fine it is too thick to be wound tight enough to get a good fill factor. Regarding the effects on...
by Geoff V
Sat Dec 29, 2012 1:11 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: v8 Alpha stirling generator concept
Replies: 19
Views: 12435

Re: v8 Alpha stirling generator concept

John Extracting power from the Stirling cycle is very difficult, requiring sophisticated heat exchangers and lots and lots of pressure, starting with an engine which was designed as an ICE precludes the high pressures and limits the choice of heat exchangers. In terms of effort and cost I'm not sure...
by Geoff V
Fri Dec 28, 2012 11:11 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: v8 Alpha stirling generator concept
Replies: 19
Views: 12435

Re: v8 Alpha stirling generator concept

Ian I forgot to answer you question regarding the Jim Dandy#3. With a working volume of 412cc and 500w at 4barg, this would equate to about 125w at atmospheric ( or a little more, due lower friction) which gives 0.303watts/cc, for a purpose built SE this sits nicely at the top end of my 'rule of thu...
by Geoff V
Fri Dec 28, 2012 10:39 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: v8 Alpha stirling generator concept
Replies: 19
Views: 12435

Re: v8 Alpha stirling generator concept

The question of displacement ratio is dictated by the ability of the heat exchangers to raise and lower the mean temperature of the working gas. If the mean WG temperature is too low, the WG will not have expanded enough to maintain a pressure difference across the piston and there will be no drivin...
by Geoff V
Fri Dec 28, 2012 11:09 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: v8 Alpha stirling generator concept
Replies: 19
Views: 12435

Re: v8 Alpha stirling generator concept

Johnmaster Dry running SE's use a modified PTFE such as Rulon or Crossflon for the piston bearer rings and the sealing rings, the rest of the bearings are usually low friction sealed ball or roller races. Regarding your proposed temperatures, an alpha configuration with the same size bore and stroke...
by Geoff V
Fri Dec 28, 2012 3:46 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: v8 Alpha stirling generator concept
Replies: 19
Views: 12435

Re: v8 Alpha stirling generator concept

Johnmaster IanSC raises some valid points regarding bearing and piston ring friction, but there are several other fundamental problems. Firstly, the cylinders on an ICE are rather too close together to permit coaxial heat exchangers, so it would require tubular exchangers where the tubes have to sit...
by Geoff V
Sun Dec 23, 2012 12:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: HYDRIDE DISPLACER
Replies: 2
Views: 3073

Re: HYDRIDE DISPLACER

Fullofhotair I've read and reread your proposal and am clearly missing something. The two, one way valves, in which direction do they allow flow? If they both work in one direction, how does the working gas reciprocate from one end on the displacer to the other, as it is a close fit? If the valves w...
by Geoff V
Sat Dec 22, 2012 6:16 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Regenerator material option
Replies: 9
Views: 8118

Re: Regenerator material option

Gentlemen As promised, an update on the regenerator material tests undertaken by Ian Larque. The engine is a pressurised beta of 46mm bore with a unique crank mechanism which permits the strokes and phase angle to be varied between runs. The hot heat exchanger is slotted internally and externally an...
by Geoff V
Fri Dec 21, 2012 6:19 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Elastic Regenerator
Replies: 34
Views: 23172

Re: Elastic Regenerator

Tom

There is always room for improvement, but as the current regenerators are reported as 95% efficient in terms of heat recovery, there's not much room, so I wish you well with your endeavours.

GeoffV
by Geoff V
Thu Dec 20, 2012 12:10 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Elastic Regenerator
Replies: 34
Views: 23172

Re: Elastic Regenerator

Tom So many questions, where do I start? OK. A heat exchanger is a device which transfers heat from one fluid to another through a solid membrane. The part of the SE you heat, transfering heat (from the external heat source) to the working fluid (air) inside the engine, is a heat exchanger. Similarl...
by Geoff V
Wed Dec 19, 2012 3:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Elastic Regenerator
Replies: 34
Views: 23172

Re: Elastic Regenerator

Tom I started life as a car mechanic before spending 4 years designing small hovercraft, then 22 years as an Airline pilot and finished with 7 years running a precision engineering company as a sub contractor to one of the Formula 1 teams. During this time I have designed, produced and marketed a fu...
by Geoff V
Tue Dec 18, 2012 10:20 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Index of modern Stirling engines
Replies: 6
Views: 9530

Re: Index of modern Stirling engines

Sir

Norris will be thrilled that his engine is now producing 1Kw.
spinningmagnets wrote:1-kW Norris Bomford small boat engine, vertical 3-cyl Beta's
Sadley I think an extra nought has crept in to the reported performance unless the new owner Mr A Hall has tweeked it a bit, crafty old fox.

GeoffV