squid

What is good, especially for centrifugals?

Obviously, there are a number of "price classes," such as Free, $100, $200, $500, and more.

I want to work out cam timing with a centrifugal.

Thanks
Tom

PS. Pretty much not interested in anything which doesn't at least use the Method of Characteristics.

gametech

iTrader: (1)

Given the real world knowledge base available, I would ignore any software-based predictions . Ask yourself if your goals are really that much different than what someone has already done.

SethU

Certainly could take that route if the end goal is the end goal.

Doesn't do much in the way of education, understanding, and curing curiosity though.

Monkey see monkey do... or monkey learn monkey do. Neither right or wrong.



I'm curious too. Haven't used one in years. What's being used now-a-days?

stevieturbo

If you are needing to ask here....then could you really provide such software with all the relevant data in the first place for it to even attempt to simulate a result ?

And any such software worth using, will cost thousands of dollars.

If you want to work out cam timing properly and optimally for your engine...spend that money on dyno time and test it.

Otherwise stick to what the cam supplier/grinder recommends....as they will have done the simulations/guesswork already ( you hope )

alocker

iTrader: (10)

I would tend to agree with this statement unless you just have tons of money and time laying around, then go for it.

squid

I'm looking for a preliminary design phase tool for an engine development program.

pantera_efi

iTrader: (1)

I ALWAYS do this work using EAP-Pro from Performance Trends., EVERY engine rebuild.

When one "port flows" the head AND uses a Cam Doctor/Lobe File for the input specifications, the results WILL be within 5%.

Another reason is I then have a "setup sheet" for future reports.

Just ask, I will do this for FREE.

Lance

truckdoug

iTrader: (25)

thats pretty neat. thats the kinda stuff i wish i had more time for.

93camaro_zzz

iTrader: (13)

This could do everything you wanted to do. But I'm quite certain you don't want to pay for it.

http://www.ansys.com/products/Fluids/ANSYS-Forte

roastin240

iTrader: (13)

I use Ricardo WAVE for 1-D engine simulations. For in-cylinder CFD for our engine designs I use CONVERGE....I forget what WAVE costs but we spend like 5-10 grand a year on it if I recall and CONVERGE is 40 grand for a 1 year license. Obviously not justified for your average motorsports enthusiast.

But I agree 100%. Basically everyone is monkey see monkey do. I must understand all the nitty gritty details...but being an engineer by trade, all day every day, I cannot accept any less. I am not down to just copy someone else's build who was successful. I will estimate airflow vs. pressure and plot a trace through a compressor map to see where I am at throughout the entire engine operating range, etc. rather than just buying a turbo everyone says is awesome (just 1 example). And take it "too far" as most would say. But I dont do this just to be fast, I do this to exercise my skillset and learn more. Sounds like your after the same thing.

pantera_efi

iTrader: (1)

Thanks, to those who use science.

I have used EAP for more that twenty years, thus a great data base.

I KNOW one item, for sure, that finds a problem that has never been in error.
That "item" is an error in engine design found by a model of the engine.
ALL can agree ?

I was supplied with Ricardo WAVE used for testing with my "camless" Ford Ranger 2300.
My customer was FEV.

Lance

squid

Yes, I have made no progress in 2 years. One year I spent, literally all my time, reroofing my house - I'd like to forget that.

However, I have been looking at the affordable stuff with EAP Enterprise @ $750 sounding interesting, but disappointing when they specifically warn NOT to use the software to match turbos. (sad emoji)

One criteria for a good program would be the ability to see that the move to high efficiency turbos resulted in back pressure less than boost and cam designs becoming like normally aspirated.

If the software can make that distinction, then that is a pretty good package. EAPent has compressor maps but NO turbine maps. I do not believe they can predict turbo backpressure. But they appear to be able to predict turbine shaft HP.

I'm a FEM jock from Pratt & Whitney and had ran a transient thermal analysis of a split compressor case to predict the change in compressor blade tip clearance... that ran for 17 days on the biggest/fastest RS6000 at UTRC. So know about all this 3D stuff.

But just a good 1D code using Method of Characteristics for wave action would be just fine. 1D finite difference is not that hard.

Consider that Matlab was $25k to purchase and now you can get it for $150. There are now free CFD codes out there but it doesn't look like GT Power, Ricardo, etc. are feeling any heat. Yet. Some day, some sharp tuner kids from MIT will write something in Python that will eat everyone's lunch... (must check Python libraries now...)

EDIT: ...check this out. A white paper with all the equations for the various components of the engine: VALIDATION OF A 0D/1D COMPUTATIONAL CODE FOR THE DESIGN OF SEVERAL KIND OF INTERNAL COMBUSTION ENGINES

gsteele

^^^ You sure that is a good link? 2:20 AM and it is not working for me.

squid

My Bad...

Try the link again, the original one I posted was to the pdf file that was created on my PC. I corrected the link to the URL that opens the pdf. (Doing a search on the title would work too.)

squid

Just thought I'd touch base to see if there's anything new out: simulation software that can predict turbo backpressure.

Trying to understand how a moderate HP TT build (800-1000hp) results in 30 mpg in a 500 cu in engine which is a far greater mpg than when it was OE NA .

I would speculate that this 30 mph state could be achieved NA if the sole objective.

LetsTurboSomething

Gas mileage is much more complex than cam power. High mph on larger engines is usually the result of leaning them out and running a compression and squishband clearance that allows for 15-16:1 AFR's in cruise.

30mph in a 500ci engine is the result of gearing, fueling, weight, aerodynamics plays maybe the largest part here. It's so much more than just the engine let alone the internals of the engine. Transmission advancement is huge for efficiency.


But really for seeing what a cam will do...they don't simulate it on software from what I've heard and seen of the major cam cutters. It's all trial and error and they literally just keep cutting cams and changing things until they dial one in that's just right. The cam they stick in a box and sell you is the result of probably hundreds of test cams in the scrap bin.

gametech

iTrader: (1)

The last 5 years of your life should hopefully explain my first answer to you. If not, good luck on wasting the rest of your life chasing computer theories that some random internet user turned into a software model.