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single cylinder engine software

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I tried using that many years ago and just ended up frustrated, maybe the newer versions are better?

Save one of your files and post it, I'd love to see what a finished set up looks like.

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I just downloaded the software, don't know much about it, but it looks really interesting. What kinds of things can you do with it? I'm interested in determining the amount of air in the cylinder given throttle angle and engine RPM. Is that possible??

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I'm reading through the docs now, it looks really good! I had been working on my own compressible air flow simulation of just the throttle body and cylinder. Needless to say, it's a lot of work. I was getting interesting results, but I wasn't sure if the simulation was accurate.

My goal is simple. If I can determine the amount of air in the cylinder with reasonable accuracy, I can more effectively determine how much fuel the engine needs to achieve a specified AFR. I was getting there with my simulation, but it had a way to go.

Let me know if you learn more about the software. It was nice of Lotus to give away the single cylinder version for free. Fortunately, that's all our thumpers need :lol:

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OK, I got it working yesterday. It is really, really cool! I had to go through the tutorial to learn the design flow. I put in most of the geometry for my DR350S. I had to guess on some of it, e.g. valve lift. The model requires a plenum, which is quite small in my case. That seems to reduce performance significantly. I still have some parameters to tweak, but so far, it's in the ballpark of what the real engine does.

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Can the volume within the air filter be taken as the plenum, and then the balance of the intake tract as the port, or will the simulation not work right that way?

Here's an image of my engine model:

engine-model.png

From left to right, the components are:

1. Inlet (no air filter or other restriction)

2. Throttle (42mm FI TB with simple butterfly)

3. Plenum (volume is 0.084 liters, just a WAG)

4. Intake port with two valves, each 30.6mm diameter

5. Intake valve with guestimated lift

6. Cylinder

7. Exhaust valve

8. Exhaust port with two valves

9. Unrestricted exit

So you have to include a plenum between the throttle and intake port. The software is quite particular about which components can connect to others. It took me a few minutes to figure that out.

The box with green fluid is the fuel model. I chose gasoline, but it will accept other fuels, e.g. Diesel, methane, methanol, or user defined fuel.

I would strongly recommend downloading the software and going through the tutorial. You can easily see the effects of different variables without wrenches and dyno. They say the simulation is quite accurate, but as the saying goes, garbage in, garbage out. There are still a few banana peels in my first attempt :lol:

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I remove the plenum, I don't have one on my engine, so why should I simulate it?

I use the concept tool to set my engine and remove the plenum.

setup the model in the concept tool and when bore and stroke etc all set, go to

file..close (make current) and your engine appears on the page. I then go through and correct any anomalies.

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