measuring /logging air speed ?

[relaxedphit]

Just wondering. When I was shooting long range (1000 yds) slowly rolling the focus back with a 60x power spotting scope, you could see the heat waves moving in different directions. Does the wind direction vary across a particularly long distance - like Bonneville. I'm sure this is not significant at a short course like we have at Maxton, but could this be a factor on a longer course?

[Glen]

Yes, the wind at Bonneville cad blow in different directions along the long course.

[Seldom Seen Slim]

As a great example -- during the Top Speed Shootout Mike Cook will request wind readings from the various course watchers as a vehicle is being final-readied for a run.  We'll hear speeds from the zero, the three, the tower, the lights (about the 5 1/2) and at least one more, maybe at the 7 or 8.

They are NEVER all the same -- in either velocity or direction.  The direction might be most of the 360 degrees of a circle, in fact.

Therefore, especially if you're running a fast vehicle - it's wise to ask for a wind reading form the starter before making a run at any event.  Informed might just be safer.

[racer x]

I always thought your car comes to the air!

kent

haha! Thanks for keeping me honest Kent.  After 6 years in the wind tunnel I guess I view it different than most.  Same concept as I stated before but as the car goes through the air.. 

I believe that is called a Galilean Transformation"

[relaxedphit]

Hey now Eric--watch the sex talk, this is a kid friendly web site.

[racer x]

Don't drink and post Don't drink and post  Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post  Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post Don't drink and post  Don't drink and post Don't drink and post 

[Cajun Kid]

 

[Dan Stokes]

I've been enjoying this thread.  Nothing to add - just tryin' to wrap my little thinker around it.  I don't have to worry about any of this for THOUSANDS of dollars.  Hopefully someday - like right after I win the lotto.

Dan

[Cajun Kid]

I've been enjoying this thread.  Nothing to add - just tryin' to wrap my little thinker around it.  I don't have to worry about any of this for THOUSANDS of dollars.  Hopefully someday - like right after I win the lotto.

Dan

Dan did you say Lotto ?

After my most recent Studebaker build that was just completed fully today..... I go by the " Notso" theory,, and just hope for the Lotto..

Building an LSR Car is easy          --- "NotSo"
Set a Budget and Stick with it    ---- "NotSo"
Set a Timeline and finsh as expected --- "NotSo"

I am sure there are many more "NotSo's"  these are my most recent 3 ....

Charles

[racer x]

Living life to the fullest ----"Notso"   but we try

[38flattie]

When track testing it there are many variables to keep track of that will affect the results of your test.  The one thing you cannot control is Mother Nature.  Temperature, barometric pressure, and wind conditions are constantly changing during the day.  As you guys know, the wind will never be a constant speed or direction.  You must log your input readings as a function of position on the track and your readings must correspond with each other, in order for you to match wind speed, angle, ground speed as they are happening on the track.  Along with a pitot tube you can use a device to measure wind angle.  It is a wedge shape probe that sees pressure on both sides and you can calibrate it to yaw angle so you can plot it to see what the wind angle is on a particular run at any location/time on the track.  Simple to machine, and I will see if I can get an image up once I'm back at the office next week.

I think this is the only way that any beneficial info can be collected. Simple airspeed is worthless, as several have explained, to due changing wind speeds, direction, etc. Even with measuring the wind angle, wind speed is needed.Will this do that?

This is a great thread, but I'm wondering what is to be gained here? Track conditions will always be different, and winds unpredictable. If it's the effect of wind on the car and speed, wouldn't wind tunnel testing be more benificial.

I'm new, and certainly not trying to be disrespectful, but simply asking for educational purposes.