Wet Sump Testing

[FormulaDIT]

Here is the problem. This is our first year in class 1 of the Formula Student competion and we do not have a running car to perform tests on the sump. We are currently running a GSXR 600 Stock Sump. We are looking for a way to test lateral acceleration conditions on the sump, pressure drop etc. We are just curious to find out how other teams have tested there sump. Computer simulation, test rig, on track etc. Any help would be much appreciated.

[FormulaDIT]

Here is the problem. This is our first year in class 1 of the Formula Student competion and we do not have a running car to perform tests on the sump. We are currently running a GSXR 600 Stock Sump. We are looking for a way to test lateral acceleration conditions on the sump, pressure drop etc. We are just curious to find out how other teams have tested there sump. Computer simulation, test rig, on track etc. Any help would be much appreciated.

[Zac]

I'm not an engine guy, but wouldn't the easiest way to test for lateral acceleration on the sump just be to rotate the motor?

[Wesley]

I always wanted to build a tilting engine rig, so you could just lift the engine as it was running to slosh the oil back and forth.

I never did though. We always had a car to test in, and just used a pressure transducer.

[Demon Of Speed]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Zac:
I'm not an engine guy, but wouldn't the easiest way to test for lateral acceleration on the sump just be to rotate the motor? </div></BLOCKQUOTE>

I know at GM they have tilt table engine dyno's for this exact use.

May be Axleripper will add to this.

[dazz]

Have you seen this vid of the Porsche test rig that simulates a lap of the Nürburgring?

Find it here at youtube dot com/watch?v=fv53RbvgfGc

Pretty impressive stuff!

[wagemd]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dazz:
Have you seen this vid of the Porsche test rig that simulates a lap of the Nürburgring?

Find it here at youtube dot com/watch?v=fv53RbvgfGc

Pretty impressive stuff! </div></BLOCKQUOTE>

That's amazing. Looks like they told the driver to just rail it for the data profile...

[AxelRipper]

unfortunately I cant see that video here at work, but I'm sure its roughly the same rig that is used here in one of the dyno cells. Supposedly you can simulate ~1.5 g turns and acceleration on it, possibly more. I've seen videos of it testing FWD v6 engines on an MRC simulated course, and its rather impressive.

As for doing it yourself, I could see possibly coming up with something roughly like it, maybe manually operated and able to be locked in place so you could tilt the engine. I'm sure the easiest way to dyno would be to tilt the engine to about a 45 degree angle and see what happens.

I'd imagine the safest and easiest way to just test it would be in car however. That is, unless you can get access to a company with a tilt rig.

[FormulaDIT]

Thanks for the replys. We will most likely be building a manual tilt rig. Another idea we have is to make a rapid prototype of the sump out of a clear acrylic and attach it to a car or go-kart and obsevre the oil condition using cameras and sensors.

[wagemd]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by FormulaDIT:
Thanks for the replys. We will most likely be building a manual tilt rig. Another idea we have is to make a rapid prototype of the sump out of a clear acrylic and attach it to a car or go-kart and obsevre the oil condition using cameras and sensors. </div></BLOCKQUOTE>

Make sure you post or link pictures of the rig when your done, I know I would like to see the finished project.

[Adambomb]

We built a tilted dyno stand a few years ago to test a trap door wet sump system. It worked fine at 60 degrees just sitting there all tilted. On the track, however, the oil pressure light would come on at just over about 1g (according to my butt dyno http://fsae.com/groupee_common/emoticons/icon_wink.gif ), even in a seemingly more or less steady-state (or as close as we could come on university parking lots with amateur drivers) skidpad.

To fix it we just kept adding oil until the light quit coming on. We lost maybe 10 hp or so according to the chassis dyno in Detroit, and it smokes on hard right-hand turns. We named it Smokey. Still got 18th in Detroit in 2007, and was more or less a clone of our 2006 car that got 7th.

[Wesley]

Steady-state is a lot less important than transients. Almost all of our testing data showed transients were where the problem lay.

If you think about it, the angle the oil has to be at steady state to uncover the pickup is huge. The problem is when you pop into that 1.2G skidpad, the oil swings up and oscillates until they decay into some marginally steady-state corner, then you flop sides and that oil builds up a lot of flow momentum and crashes past the pickup.

Oil pressure doesn't decrease by some function of lateral g, except as a step-wise function.

What'e important is to gauge your baffle systems effectiveness in terms of reduction/elimination of low pressure events, which means testing in transients. That can be done on CFD or an accurate mockup, but most easily in a car with a pressure transducer.

We found that instances of high jerk were those that were most likely to cause low pressure events, not sweepers, not constant G turns. It's when that oil sloshes back and forth that you start having problems.

[RANeff]

Wesley is correct, steady state isn't really the problem in a wet sump system, its transients.

As a sort-of event study, I looked back over our data from SCCA Nationals, were we were cornering at over 1.4g steadily for very extended periods of time; we didnt have pressure problems. Our pan is a very short sump with baffles/windage tray.

But, any low pressure events we see are always right when the car changes direction. I would like to see some tile-table work or something, it sounds interesting. Good luck!

[FormulaDIT]

Thanks for the heads up on the transients. Could have easily let that slip considering we don't have a car to test the engine in yet.

What program are people using to run CFD analyses. We will more than likey be using Ansys.