Crank/valve train model
Crank/valve train model
(OP)
All
What are the industry standard softwares for crank/valve train modelling for automotive engines?
Has anybody evaluated these tools?
What are the limitations on these??
What are the industry standard softwares for crank/valve train modelling for automotive engines?
Has anybody evaluated these tools?
What are the limitations on these??





RE: Crank/valve train model
You could use your requirements and look at the above site to create a checklist of what you might want to achieve and then measure any products by seeing how much of your checklist is offered by particular products.
RE: Crank/valve train model
RE: Crank/valve train model
RE: Crank/valve train model
RE: Crank/valve train model
I'm not sure that the roundy roundy uppy downy bits (cranks and pistons) really gain much from ADAMS analysis although I suppose you could examine piston slap and bearing loads.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Crank/valve train model
I was also asked to model FEADs to predict gear rattle in the timing drive of a big diesel. That was even less suited to ADAMS than the "roundy roundy uppy downy bits" - a highly stiff 1D system.
This is not intended to be a pop at ADAMS. I liked using it and built many interesting models. I just got the impression that we had an expensive tool looking for problems to solve to justify its annual lease. And many of those problems could have been solved quicker, cheaper and more accurately using other tools.
RE: Crank/valve train model
Does it mean you cannot do coupled (crank/block)analysis within ADAMS.
RE: Crank/valve train model
RE: Crank/valve train model
Given enough time and motivation you can do anything, appropriate or not. ADAMS is a lumped parameter modelling system and models those types of systems best. FEA is inherently a distributed parameter modelling system. While there are methods of including reduced FEA models in lumped parameter models, it's always a shoe-horning job.
Take a look at MSC's promo material:
h
RE: Crank/valve train model
http://www
However, on their website they include several very interesting articles they published in "Race Engine Technology" on the Cam and Valvetrain Design process and how this is best applied using their software.
These are not tech articles like SAE etc, but are instead very intuative guides for the Cam/Valvetrain designer.
RE: Crank/valve train model
Thanks for the the clarification facty.
RE: Crank/valve train model
The articles that I downloaded from their site (mentioned in my initial message) are in pdf format and are definitely worth the read if you're involved in Cam/valvetrain design.
RE: Crank/valve train model
RE: Crank/valve train model
I agree with your approach on wanting to investigate the design boundaries using CAE tools. For this type of investigation I would use a 1D engine performance simulation tool (Optimum Power, Gamma or Ricardo) to analyse the potential performance gains from changing geometry and valve timings/lifts etc. Having obtained an optimum design I would then check that it was mechanically feasible by using a tool such as 4stHEAD that is described on the Blair website (others would be GT-Vtrain, Valdyn etc).
Finally the mechanics of the crank could be analysed either separately or linked, depending on what CAE tools I had at my disposal.
I have used Optimum Power's Virtual Engines 1D software in the design arena before and have experienced reasonable success with it. The key to using any 1D software is to appreciate and realise their frailties.
Regarding the Cam Profile Design and Valvetrain Analysis tools out there, I have recently heard very good reports on the Blair software and saw the Presentation he gave at the motorsport Symposium in London back in November. However Gamma and Ricardo also have tools for this application.
In high performance engines I have seen significant gains from investigating the coupled effects of the torsional vibrations in the crank and cam and how this will affect the ensuing engine performance.
I could go on for ages, but the bottom line regarding CAE tools is your own specific design applications, resources and future plans.
All CAE tools are very expensive and can only really repay their investment if they are being constantly utilised. Some may even be the proverbial "hammer to crack an egg" so it is important to know exactly what they are all capable of doing, their strengths and weaknesses, although the latter 2 may only be apparent after you start using them in anger!
Most people tend to play safe so the perceived "bigger" CAE suppliers get bigger at the expense of those that may suit your purposes better. The plus is that most CAE tools have yearly licences, so you can chop and change if you are fortunate enough to have the time to do so.
I think I've gone on for long enough!
RE: Crank/valve train model
I've only played with it, not having an engine project on the go, but it seems to be a useful piece of work.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Crank/valve train model
Alternatively the other 1D code suppliers may give you demo versions if requested.
RE: Crank/valve train model
an existing four stroke engine 1600cc by altering the geometry while keeping the number of carry over parts as minimum as possible .
Hence as you suggested 1d tool will be used for performance, but at the same time the boundary conditions i.e forces,pressure etc on components will also change and I want to see the boundary conditions after the mods to make sure the structure is sort of ok. What tools would be ideal for this type of work.
RE: Crank/valve train model
RE: Crank/valve train model
RE: Crank/valve train model
Doc
RE: Crank/valve train model
The other valvetrain analyses packages already mentioned in the previous replies (such as the 4stHEAD, Valdyn, GT-VTrain softwares etc) simulate full dynamic analyses of the valvetrains.
A very interesting outcome of a dynamic valvetrain analyses on a NASCAR exhaust valvetrain has shown that actual valve opening can be retarded by up to 10 degrees cam rotation due to the in-cylinder pressures and the flexibility of the particular pushrod system. No Spintron testing will ever show this to the engine designer!! (It can be validated by looking at the output from pressure transducers in the primaries)
RE: Crank/valve train model
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Crank/valve train model
He told me that the total twist in shafts etc from engine to wheels could total 360 degrees in a formula one car that had to be re-wound up after a gear change.