Cool 2d fluid physics program... and it's free!

[Capt. Vulcan]

It's a demo program for some japanese program called the Octave Engine. http://www.octaveengine.com/en/casual/trial.html

It operates like a basic paint program, only you can use the radio buttons to give what you painted physics properties like water, fire, walls, elastic slush, ect. Not really intended for any kind of serious physics people, more of a fun program to muck around with. But placing heat on water will cause it to evaporate in to steam, which will condense when in contact with the cooler, ect.

Some quick tips, the inflow means that water will flow in from whatever you paint with it, outflow will act as a drain, fuel is jut a rigid object that can catch on fire, I haven't figured out what jet does.

Have fun!

 

[Jadzia]

Cool! And it has gunpowder. :-)

I wonder how they've modelled the gas convection.

Jet is a motor. It applies force to what it is fixed to. For example, use a blob of axial to create a pivot, stick rigid strips to it, stick a couple of jets on the sides, and you've made a spinner. Then put a circular wall around it and add 1/3 water and you've built a washing machine :-)

Mochi is thixotropic like meringue. You can create a pile of it and wash it away with a water spray. It's just like doing the dishes.

 

[Capt. Vulcan]

Well, apparently jet has some strange properties when it comes in contact with certain things. I guess it's sort of a fantasy material put in so you can dump in an element of chaos into whatever your making. If you want to see how it works, make a cup and put some mochi in to it, then drop a bit of jet in to the mochi.

oops, just noticed that you edited your post. Yeah, jet is pretty interesting. There are a bunch of videos on youtube of people experimenting with the program. Apparently it's being used for the next tekken game to model water. I've gotten more enjoyment out of this program than pretty much any game I've played this year.

 

[Jadzia]

When I was at university, I began writing a program reminiscent to this as a project. It tried to model solid materials by approximating them with discrete particles - elastics and tensile and such. It also did magnetic charges. It wasn't as powerful as this japanese thing. Water behaviour is the most interesting. How to get it to slosh. I tried doing water -- there is some cohesion due to its ionic nature and surface tension, where nearby droplets will stick together, but water pressure prevents them from coming too close. So a 1/r^2-1/r type of force curve. It works to some extent but it doesn't slosh. It does produce ripples and waves on a surface though.

One thing I don't like about this program is that steam has no pressure, and gas does not diffuse nicely. It wouldn't be hard to implement if steam particles simply repelled one another instead of chasing around the walls.

I did a steam engine too -- that was the climax of my project. That was how I did steam, and it worked.

 

[Jadzia]

Hi Captain,

Mochi is sticky, and unlike other materials in the program, it will adhere to whatever it touches. Even viscous fluid will stick around it. The reason it behaves erratically when mixed with jet is because it sticks to the jet, which causes the jet to apply force, which fires the jet through the mochi and disturbs the whole thing.

To be honest, jet is not a real material, but a never ending supply of kinetic energy.

I would be interested to see the force equations for these materials. Any ideas what they are? We can change to coefficients in the advanced section. So working with just a couple of particles, and setting most coefficients to zero (or infinity) should limit the dynamics and make it easier to analyse.

A little project for you

 

[ThunderAeroI]

I have been tryiong to make a steam engine for the past 24 hours and I am no closer to getting something actually working a full cycle. I have tried three different types of steam engines, but I can not find a way to link multiple ridged objects to create a lever. The steam also will not move an impeller to any degree, but ou can move a piston rather well.

 

[Jadzia]

How are you getting on Thunder? Have you worked out how to do it yet?

Here's clue: Steam in this program has virtually no pressure because it naturally occupies the same volume as water. So a conventional setup won't work. You need to redesign your valves.

 

[ThunderAeroI]

How are you getting on Thunder? Have you worked out how to do it yet?

Here's clue: Steam in this program has virtually no pressure because it naturally occupies the same volume as water. So a conventional setup won't work. You need to redesign your valves.

so do the same thing with water rather than steam... i know water will push a value due to previous tests; however, im not sure how id get water pushed though a system.

 

[ThunderAeroI]

i give up, i cant make the piston or the level the right size and the program causes leeks like no tomorrow.

I did get one cycle completed by cheating... adjustiong the size of things while the cycle ran, but that isnt good.

 

[Jadzia]

Big Clue: You can use steam but you need a two piston engine

 

[Gertch]

A friend did some neat stuff with the Mac (don't tell him I said something positive about the Mac).

http://www.youtube.com/watch?v=t7UgfTRzq5k

Yeah, he's having fun...
http://www.youtube.com/watch?v=6q2iMgwuj68

 

[ThunderAeroI]

Big Clue: You can use steam but you need a two piston engine

doles it have to be four cycle or two?

 

[Jadzia]

Each piston is two cycle, but the whole... It depends how you look at it. I don't wear a yellow uniform Thunder, so forgive me The pistons must be pi/2 out of phase. Each piston switches the valves of the other.

Without two pistons, a single piston stalls inbetween valves opening and closing. This is a direct consequence of the low pressure low momentum of the system.