RE: the original (old) question), we are in the lucky position of using many of the codes mentioned in this thread. If I had to make do with one, then it would have to Abaqus, mainly due to the large amount of contact analysis we do, since I work for a brake manufacturer. I'm not trying to be...
The motoGP championship kicks off this weekend and one of the intersting things to come out of the summer testing is the new "big bang" in-line 4 yamaha. The word is that they worked on 4 different firing order configurations (basically on the same in-line 4) but the final product is very rough...
Yeah, the explainations I have seen relate to the rate that the pulses are applied and how the tyre copes with regaining traction in between pulses. But I've not seen a good techinical expalination. The flywheel weight stuff is all straight forward, but many believe (me included) there is more...
Thanks for your reply. I figured the flywheel weight would be a big part of it, but I wonder if that is all. People do make 4 cylinders with differing firing orders, hence, maybe require different flywheels. I think if it was purely a flywheel weight issue, why not just use a heavier flywheel...
OK, I think I might not have made my question clear enough. I wasn't asking regardling different numbers of cylinders, just different numbers of firing impulses. Will firing order ALONE, make any difference to an engine's ability to get traction or any other characteristic.
The 500cc GP...
Hi All,
This is a question I have heard a bit about but have never read a decent believable technical explaination. It relates to changes in firing order has on traction and engine characteristics, especially concerning motorcycle engines.
The basic belief is that a 1000cc V-twin powered...
You can define a group that contains the nodes that you are interested in. In the results window you can create a report that contains the group you are interested in and write the x, y, z node locations to a file. You can only access the results if you have a results file. There are probably...
This thread has started to sound supiciously like a discussion in a hot rodder magazine - ie, importance of torque vs power, capacity specific outputs, etc. Surely you can see past those.
What does it matter what magintude of an engine's torque output is? I mean power is work rate. So of...
Thanks Nicolas,
I never really found out why this was happening. In modal analysis the model is fine, and I have had no problems with ESE in subsequent larger models.
Cheers,
Antti.
OK, what do you actually want? No universal constant of piston speed has been found by physicists - although I suspect it's slower than the speed of light:) Some mid 90s F1 engines reputedly approached 28m/s mean piston speed. So use 28, but it may not be what you're after if you're not...
The general strategy described by Greg is similar to what I would try and do, although I am not familiar with abaqus. But as Greg also alluded to in the start, I would have limited faith in overall reults. Physical measuremnts of parts (or all) of the preocess would certainly be a help.
Normally people talk in terms of mean piston speed - ie, the stroke X 2 X revs per sec. About 25 m/s is around the maximum for mean piston speed, if you know what I mean. This is true for a lot of high revving production motorcycle and car engines, to even things like F1 engines are about this...
Just to expand a little on a slightly different (but related) topic. In the literature concerning brake squeal noise, a variety of models exist explaining the mechanism for instabilty in system with sliding friction. The negative coefficient of friction vs sliding velocity can indeed introduce...
