Coriolis effect?

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Stan Pope
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Coriolis effect?

Post by Stan Pope »

Has anyone measured or computed the Coriolis effect on a PWD car's path? Would it be enough to affect one's decision on which wheel to lift? Would the orientation of the track be a factor?
Stan
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Re: Coriolis effect?

Post by DerbyAddict »

Stan Pope wrote:Has anyone measured or computed the Coriolis effect on a PWD car's path? Would it be enough to affect one's decision on which wheel to lift? Would the orientation of the track be a factor?


Read this one as the first thing after waking up. All I have to say is:

:lol:
and
:clap:

Thank you Stan
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Any day racing PWD is a good day but winning makes a better good day!
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Re: Coriolis effect?

Post by tmbnorm »

If we are worried about the Coriolis effect from the earth on a 3 second race, I think we are taking this way too serious! :wink:
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Doug Piranha
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Re: Coriolis effect?

Post by Doug Piranha »

We are racing today for the District race and my car rides the right rail. Since in the north the effect deflects things to the right, I am going to have them re-orient the track to point south instead of north. I would not want the effect to pull my car to the up wheel.


Just in time! Thanks for the advice Stan!!!
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Re: Coriolis effect?

Post by doct1010 »

Way out of my league here. If memory serves, the Coriolis effect has influence on large mass events ie, weather systems, cyclones, missles ect. does it have any effect on a 5oz car going down a 32 to 50ft track, a 3 to 5 sec event? Or enough to influence ones decision on a lifted wheel?
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Stan Pope
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Re: Coriolis effect?

Post by Stan Pope »

DP: Not "advice" ... just a question. But you might consider asking them to move the race to Brazil. :)

The question is asked in a semi-serious vein. I don't know the magnitude of the Coriolis force, but I do know that PWD cars are sensitive and finely tuned devices. And PWD cars are deflected by much smaller forces than those which would affect the trajectory of a rocket or change the course of a hurricane. :)

As racing starts to "wind down" for the season, I thought some of the Truly Obsessed Pineheads (TOP's) would like an issue like this to mull over.
Stan
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FAST Racing
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Re: Coriolis effect?

Post by FAST Racing »

Stan Pope wrote:Has anyone measured or computed the Coriolis effect on a PWD car's path? Would it be enough to affect one's decision on which wheel to lift? Would the orientation of the track be a factor?
Why stop there.....

How about:
Phases of the Moon
Solar flares/wind
Feng Shui

Stan I hope you have your tongue FIRMLY planted in your cheek.... :roll:

As Mel Brooks/Yogurt says: " May the Farce be with you"
Father And Son T eam = F.A.S.T. Racing
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Stan Pope
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Re: Coriolis effect?

Post by Stan Pope »

FAST Racing wrote:Stan I hope you have your tongue FIRMLY planted in your cheek.... :roll:
:) Partly!

Since no one will admit to having done the research, I looked in Wikipedia. If Wikipedia is to be trusted, the effect of Coriolis can be estimated by the Rossby number. Small values indicate significant impact, e.g. 1 for a ballistic missile. Larger values indicate a less significant effect, e.g. 6000 for a thrown baseball.

Ro=U/fL
For us, U is about 3 meters / second, L is about 9 meters (for a 28' track), and f is about 0.0001. For these, Ro is about 3000, indicating the effect is very small.

However, if the system being studied is "finely tuned" then even small effects can be "significant". To the extent that the car is deflected, it will be deflected to the right in the northern hemisphere.

So, the question does not seem as urgent as it did last night. But I can't, based on the information acquired so far, discount it out of hand. A subject for study when I have more time ... a lot more time! :)
Stan
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Re: Coriolis effect?

Post by M7 Racing »

Tongue in cheek or not. If you could give me a somewhat valid reason why our cars would go faster if I wore a purple shirt, I would be going to the races in a purple shirt! :D

I can't imaging this force on the car being significant enough to adjust the performance, however it never hurts to ride the right rail just in case. It can just be one of our many traditions that might never affect speed but gives me a reason to discuss more science with the boys and have a ton of fun believing we might have some type of knowledge advantage over the competition.
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Re: Coriolis effect?

Post by tmbnorm »

Tongue in cheek or not. If you could give me a somewhat valid reason why our cars would go faster if I wore a purple shirt, I would be going to the races in a purple shirt!
Purple shirt? That is just foolishness.

But everyone knows that you have to put a lucky wheat penny in your right pocket and stand on your left foot when ever your cars runs down the track. That combination makes it fly!
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Re: Coriolis effect?

Post by doct1010 »

Shoot! Guess I been doin it all wrong, pink shirt AND a buffalo nickle!
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Re: Coriolis effect?

Post by davem »

A few years ago I calculated the Reynolds number to see if the vortex induced flow separation behind the open wheels was a significant drag force on the PWD cars.

My books and calculations are lost in storage, but I do recall that the Reynolds number was so low that the effects would not even show up on the charts.

There are just some things not worth worrying about...but they will still keep some of us pineheads up at night anyway.
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Re: Coriolis effect?

Post by SuperDave »

It's a good thing that all the racer's hold their breath during the race! And...we better keep the doors and windows closed.
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Re: Coriolis effect?

Post by joe »

I looked at the coriolis effect years ago when working on my thesis. There are scientists that suggest meanders of streams are caused by the coriolis effect. I couldn't find anything to prove this one way or another -- but suspect this is not true because you would see less meandering as streams approach the equator, and there seem to be far too many other forces that affect meanders. IF I REMEMBER CORRECTLY -- the effect is increased as your position approaches the poles -- one has to imagine a square of earth and what happens to it's positioning as the earth spins. The effect is principally a measure of the effect of earth's rotation relative to the direction of the wind, (or water to a degree -- toilets?). But the wind and the earth's surface are essentially "free" of each other, which causes the wind to appear to "deflect" because it is not "attached" to the rotating earth. I don't see the pinewood car and the track/earth as being free of each other. If they were, you would think that if the car was placed STATIONARY on the flat of the track that it would still be "deflected" somewhat from it's position. The same with all other objects in the room. They are not being deflected relative to you, the track, etc.
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Re: Coriolis effect?

Post by GimpyPaw »

This thread is EXACTLY why some people think there are a few of us who are a few feet shy of a short track. My wife walked by while I was reading this. She read it over my shoulder and made some incomprehensible comment about me being certifiable. :?
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