Hello Tore,
Simon pointed me to this great thread, I'm developing a Type VII simulation game.
It's amazing to read what kind of details you remember after many decades! I hope you could answer me some questions (unfortunately actually I have a lot of questions).- I'm currently working on the simulation of the G.W. engine for my game.
The load is simulated with a simple calculation (propeller law) so it's like a test bed.
http://www.wolves-of-the-atlantic.com/downloads/Enginetest/Enginetest.html(It will load the Unity plugin to play the simulation which is harmless. Ignore the bad graphics, it's just to give me a primitive visualization)
My biggest problem with the simulation is the acceleration of the engine itself because it's impossible for me to simulate the resistance caused by each part of the engine. I went with the power delivered to the shaft as basis of my simulation instead.
Basically the drag of the working propeller and the diameter and weight of the propeller and shaft are limiting the acceleration and revolutions per minute. The engine power itself is based on the amount of fuel per revolution (can be controlled with the slider).
It seems that the simulation matches the real world thing.
But what about the time it takes to accelerate engine RPM? I have absolutely no idea how fast such an engine can accelerate to different RPMs.
- And the fuel consumption shown in the simulation, does it make any sense to you?
- Another question is the AK speed (highest continuous) which should be 470 RPM, was it really possible to run the engine at 470 RPM for longer times? And 490 RPM for something like half an hour?
- From what I've read on the Type VII manual I think the governor limits RPM to not exceed 490 RPM + 10% (which would be 539 RPM). How fast does this governor work? I think it pushes a kind of lever to limit the fuel inflow, does it have a "way" from 490 to 539 RPM or does it instantly limit fuel inflow?
- The manual says the engine can't be started with the supercharger clutched in. And the supercharger can't be clutched in below 390 RPM.
Also the fuel lever can't be moved to a higher position than something that would result in about 420 RPM unless the supercharger is clutched in. Now my really stupid question: do you have to declutch the supercharger when going from higher speed to below 390 RPM???
- What is the minimum RPM the engine can run at?
- do you remember the RPM (or loss of speed) when charging batteries (at the different drive modes)?
- Is it correct that you can engage the clutch of the diesel while the engine is running up to 350 RPM? What when you switch from diesel to E-Machines? The E-Machine operate at a maximum of 280-295 RPM, do you need to reduce the diesel RPM to below 300 RPM before you clutch in the E-machine or isn't it necessary (manual says the generator can work as a brake when propellors break through the water surface in bad weather).
- how long does it take to stop and start engines to reverse?
enough questions
regards
Mark