Search found 308 matches

by Aviator168
Thu Dec 29, 2016 7:08 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engines are difficult to analyse
Replies: 6
Views: 3856

Re: Stirling Engines are difficult to analyse

Yes. I remember that; but I also like to see the machine's power output where he measure this on. Andy Ross's speed control is implemented with dead volume.
by Aviator168
Wed Dec 28, 2016 12:58 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engines are difficult to analyse
Replies: 6
Views: 3856

Re: Stirling Engines are difficult to analyse

More analysis. It is paramount to reduce dead space and at the same time increase contact area. Increasing working pressure and hot end temperature won't help a lot if dead space is a large percentage of working volume. A simple example. Say you have an alpha engine and the cooler/heater has dead sp...
by Aviator168
Wed Dec 28, 2016 9:36 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engines are difficult to analyse
Replies: 6
Views: 3856

Stirling Engines are difficult to analyse

Stirling operation are very difficult to analyse. Take a beta or gamma type engine for example. Assuming the hot end temperature is twice that of the cold end. When the displacer is at the middle moving to either side, majority of the molecules are actually in the cold side. In fact, there are twice...
by Aviator168
Tue Dec 27, 2016 5:18 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Snifting valve
Replies: 30
Views: 11401

Re: Snifting valve

Why would you want to snift out? I believe the whole point of the snifter is to equalize at the highest volume to raise the average pressure in an otherwise atmospheric engine. That's correct. Having a higher pressure in the cylinder than the crank case is not necessary a good thing in certain phas...
by Aviator168
Tue Dec 27, 2016 11:56 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Snifting valve
Replies: 30
Views: 11401

Re: Snifting valve

Same thing as alpha. Snift in at minimum volume and snift out at maximum volume. For alpha engines, both of those points just happen to be at half stroke of the cold cylinder, and both pistons produce power.
by Aviator168
Mon Dec 26, 2016 10:26 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Snifting valve
Replies: 30
Views: 11401

Re: Snifting valve

In general, alpha stirling engines have to cold cylinder lagging the hot cylinder by 90*. Assuming the crank is at the bottom. Half stroke on the cold cylinder is also the point of maximum expansion when the piston is moving down and the point of minimum contraction when the piston is moving up. Or ...
by Aviator168
Sat Dec 24, 2016 6:07 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: hot Air Beam Engine with cooling and generator
Replies: 28
Views: 8254

Re: hot Air Beam Engine with cooling and generator

I made a stainless one (0.3mm wall thickness) that gave me a clearance of 1.5mmm wall to wall within the displacer chamber, however, after running with this I found the engine was lacking power compared to the steel wool one. I had to use a little more heat for the same amount of power. A case a th...
by Aviator168
Fri Dec 23, 2016 8:35 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: hot Air Beam Engine with cooling and generator
Replies: 28
Views: 8254

Re: hot Air Beam Engine with cooling and generator

A few point on temperature. If you can get the water input/output temperature to the radiator and flow rate, you can find out heat rejection. If your engine is producing little power, this might just work.
by Aviator168
Thu Dec 22, 2016 7:44 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: hot Air Beam Engine with cooling and generator
Replies: 28
Views: 8254

Re: hot Air Beam Engine with cooling and generator

I reckon the air would flow through and cool the water easy enough if the radiator is placed horizontal That has to depend on the water temperature and the amount of heat you plan to reject. For maximum efficiency, I reckon that the water temperature would be kept at close to 100*C. Having said tha...
by Aviator168
Wed Dec 21, 2016 7:14 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Snifting valve
Replies: 30
Views: 11401

Re: Snifting valve

On a alpha engine. All you have to do is create a small air passage way inside the cold cylinder wall between the top of the piston and the skirt of piston when it is at half stroke. I am not sure how it is done on other types of engines.
by Aviator168
Wed Dec 21, 2016 4:03 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Snifting valve
Replies: 30
Views: 11401

Re: Snifting valve

Trevor, the purpose of the valve is to confirm the pressure in the cylinders with crank case in the beginning of each cycle, heating and cooling. Without the valve, a lot of atmospheric engines losses air that leads to lost of power.
by Aviator168
Tue Dec 20, 2016 9:30 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Snifting valve
Replies: 30
Views: 11401

Snifting valve

How come most of the stirling engines seen on the net has no balance valve at all?
by Aviator168
Mon Dec 19, 2016 8:46 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Plans for powerful Stirling engines
Replies: 5
Views: 4483

Re: Plans for powerful Stirling engines

To be honest. I don't like the heat exchanger of that engine at all.
by Aviator168
Mon Dec 19, 2016 4:19 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Heater & Regenerator Design
Replies: 60
Views: 26040

Re: Heater & Regenerator Design

One way to test for low conduction of heat is to make sure that the two areas are electrically isolated. Since the conduction of electricity and heat are highly correlated. OK. You mean thermal isolation. That's easily said than done as the temperature we are dealing with can be quite high. Another...
by Aviator168
Mon Dec 19, 2016 11:30 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Heater & Regenerator Design
Replies: 60
Views: 26040

Re: Heater & Regenerator Design

electrically insulated
?