Search found 22 matches

by DavesPlanet
Mon Jul 08, 2013 5:50 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53736

Re: large lamina flow build

Derwood,

any status update? Detailed construction specs of the design you have come up with? The theory and process you used to reach the current state of development?

Thanks!
Dave
by DavesPlanet
Mon Jul 08, 2013 5:43 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: RE-POST single piston hot air engine
Replies: 4
Views: 3756

Re: RE-POST single piston hot air engine

Perhaps a tiny calibrated leak to allow the two chambers to reach equilibrium as temperature increases to deal with the inconsistencies of real gas laws (as opposed to ideal laws which would maintain perfect equilibrium as the temperature of the two different size spaces averaged out).
by DavesPlanet
Thu May 09, 2013 5:32 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Re: Gas Simulation

Vamoose, thanks for the awesome videos. Several were based on a free opensource project I had never heard of called OpenFoam. I am now digging into that to see what it has to offer. harry045 my thoughts exactly on the metal-to-air transfers. The flow of heat through the metal and the gas laws would ...
by DavesPlanet
Tue May 07, 2013 5:14 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Re: Gas Simulation

Actually I am taking what I started with and re-working it into a component that can be used with JBOX2D java 2D physics engine. What I am going to build is quite simple, I am going to make particles with similar qualities to the "liquid" demo in the current download. My version will include the gas...
by DavesPlanet
Wed May 01, 2013 6:22 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Re: Gas Simulation

So I'm going to take the building blocks I have for gasses and combine them with the Java 2D physics library JBox2D

some really cool interactive physics demos available at http://gwtbox2d.appspot.com/

Dave
by DavesPlanet
Mon Apr 29, 2013 6:42 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Intro to thermodynamics - free online class
Replies: 0
Views: 10984

Intro to thermodynamics - free online class

I thought folks who design heat engines might be interested in a free online class starting next month on Intro to Thermodynamics.
https://www.coursera.org/course/introthermodynamics

Dave
by DavesPlanet
Sun Apr 28, 2013 7:21 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Linear alternator discussion
Replies: 22
Views: 27659

Re: Linear alternator discussion

Great examples, thanks!

What's with the odd triangles indicated in the displacer piston? I've seem them a lot but never understood what they were representing.

Dave
by DavesPlanet
Wed Apr 24, 2013 3:20 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Re: Gas Simulation

Just roughing out how I what the display to look as compression waves pass through. It's an 8 meg graphic, so I'm not hot linking it, click here if you want to see it. It will take a minute to fully load. You see an oscillating inner ring that presses on gas like a piston or a speaker might. As the ...
by DavesPlanet
Mon Apr 22, 2013 8:37 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Linear alternator discussion
Replies: 22
Views: 27659

Re: Linear alternator discussion

It didn't occur to me at first that this post might be a bit off topic for the forum, but since I've started it I'm going to run with it for a bit. At its simplest, a generator is wires cutting through magnetic lines of force. The more lines of force that can be cut, the more wires that can cut them...
by DavesPlanet
Mon Apr 22, 2013 11:12 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Linear alternator discussion
Replies: 22
Views: 27659

Linear alternator discussion

In searching the forums I haven't found much detail on linear alternator design, and I wanted to open a discussion on the subject. Alternators / generators work by forcing wire coils to cut through magnetic fields. There are lots of ways to move magnets near coils that are not productive, and linear...
by DavesPlanet
Tue Apr 16, 2013 5:45 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Re: Gas Simulation

Nothing yet but the initial empty Groovy project with Maven compiler and GIT version control. You can git clone it from here:

https://github.com/DavesPlanet/jupiter.git

Yea, I named a gas simulator after a gas giant. I'm a geek.
by DavesPlanet
Tue Apr 16, 2013 4:59 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Re: Gas Simulation

Absolutely, the only chance to make something that even remotely reflects reality is to use the many real world data points available here. I thought theory would be tuned to match reality, but don't we need some theory for a starting point? Somethingto start with concerning heat flow through variou...
by DavesPlanet
Mon Apr 15, 2013 12:34 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Gas Simulation
Replies: 14
Views: 6125

Gas Simulation

It seems to me that gas simulators capable of modeling basic parts of hot air engines are not available to the hobbiest. I have some ideas for putting together a gas simulator in which we could observe how gas behaves. I am interested in observing a running model that would put out graphs of heat an...
by DavesPlanet
Mon Apr 15, 2013 11:51 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53736

Re: large lamina flow build

Geoff,
regarding your helium experiment you suggest the reason a working engine could not be converted to helium is that helium overcomes thermal lag, but 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?
Dave
by DavesPlanet
Sun Apr 14, 2013 8:20 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: large lamina flow build
Replies: 97
Views: 53736

Re: large lamina flow build

Smaller bore heat tube increased power possibly due to better heat transfer? Yet regenerator does not help? Very interesting. From there the next steps might be heat fins on the inner surface of the heat tube or bundling seven very small heat tubes and seven restrictors in a nice round bundle drivin...