Search found 3768 matches

by Tom Booth
Mon Jun 20, 2016 8:41 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Tesla's Heat Engine
Replies: 19
Views: 20015

Re: Tesla's Heat Engine

Have you ever heard of Charles Tripler ? He had, back in 1890 come up with a way to make liquid air by the barrel full and found that he could use the liquid air to run a steam engine to drive an air compressor to make more liquid air. He was able to use 3 gallons of liquid air in his machine to mak...
by Tom Booth
Mon Jun 20, 2016 1:25 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Tesla's Heat Engine
Replies: 19
Views: 20015

Re: Tesla's Heat Engine

After studying all the elements that went into cycling ambient air through this machine and putting it all together in a way that made sense to me, based on basic principles, I imagine the air being cycled this way: Ambient air is drawn in by means of some form of air pump/compressor. The air taken ...
by Tom Booth
Sun Jun 19, 2016 1:49 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Tesla's Heat Engine
Replies: 19
Views: 20015

Tesla's Heat Engine

As some here may be aware I've previously posted about the possibility of a heat engine running on ambient heat. Tesla worked on building such an engine and I think somewhere in a letter claimed to have done so. At any rate he wrote about the possibility. Recently I purchased a mini metal lathe and ...
by Tom Booth
Thu Jun 16, 2016 10:45 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Eliminate the displacer?
Replies: 1
Views: 8578

Re: Eliminate the displacer?

I've often thought that a "displacer" doesn't really do anything but create some turbulence... which alternately helps to bring more air into contact with the hot and cold surfaces. Something that agitates the air while providing greater surface area might very well make for some improveme...
by Tom Booth
Thu Jun 16, 2016 9:41 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: dwell on displacer
Replies: 16
Views: 16990

Re: dwell on displacer

I've been thinking of another approach to the problem. Two displacers, one above the other moving more-or-less independently.

During the Hot phase, the cold side of the chamber would be completely covered by the second displacer and vice versa.
by Tom Booth
Sat Jun 11, 2016 10:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Designing for Torque
Replies: 12
Views: 9185

Re: Designing for Torque

The first LTD Stirlings had a slip mechanism to increase "dwell" of the displacer so that it would linger at the hot and cold side and move more suddenly from one side to the other.

A cam could be used to produce a similar displacer motion.
by Tom Booth
Sat Jun 11, 2016 9:53 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Designing for Torque
Replies: 12
Views: 9185

Re: Designing for Torque

In a four cycle IC engine that initial spark/ignition/sudden explosion... has to carry the engine through several cycles against considerable resistance including a compression cycle and whatever load happens to be on the engine. The timing in a Stirling could be controlled by having the displacer r...
by Tom Booth
Fri Jun 10, 2016 9:13 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Designing for Torque
Replies: 12
Views: 9185

Re: Designing for Torque

I'm more familiar with IC engines than Stirling, but IMO timing is critical. In an IC engine if the timing is off by just a few degrees the engine could stall under any kind of load. It seems to me that Stirling engines act quite like an IC engine that is rather badly out of time. That is, lacking t...
by Tom Booth
Fri Jun 10, 2016 6:56 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: The use of concrete for models
Replies: 8
Views: 9022

Re: The use of concrete for models

You can make the displacer directly with panels of ceramic fiber. It's stiff and light weight, and easy to work. I see some online sources for ceramic fiber of various types/brands/compositions Ebay, Etsy... some appears to be flexible (comes in rolls). Also, is it permeable ? Could air get through...
by Tom Booth
Wed Jun 08, 2016 8:19 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: The use of concrete for models
Replies: 8
Views: 9022

Re: The use of concrete for models

I've been considering making various engine parts out of a mixture of perlite and waterglass (sodium silicate) often used as a DIY furnace cement. This should, I think, be both lightweight and heatproof. There are several YouTube videos on how to make this cement. I've had several styrofoam displace...
by Tom Booth
Wed Jun 08, 2016 2:28 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: What is the difference between thermal lag and lamina flow engines
Replies: 36
Views: 32525

Re: What is the difference between thermal lag and lamina flow engines

In all engines I've previously seen of this or similar type, the choke is located very close to the heat source.. My impression being that this is necessary in order to force an air stream into the regenerator for heat exchange. If this is the case then the hole in the bottom of the tuna can would o...
by Tom Booth
Thu Apr 16, 2015 7:53 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling Engine Thermodynamics
Replies: 251
Views: 162814

Re: Stirling Engine Thermodynamics

For anyone who might be interested I have posted an Indigogo campaign to raise funds to build a prototype Stirling Engine. I've been theorizing on this subject for years and if possible would like to move beyond just theorizing an making sketches and such and do some real testing. According to Tesla...
by Tom Booth
Sun Apr 05, 2015 4:06 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: This might be useful for low power stirlings
Replies: 22
Views: 19886

Re: This might be useful for low power stirlings

Compression of a small amount of air can generate considerable heat.

https://www.youtube.com/watch?v=htObjxzwLBQ