Name this sensor...

[Ericd]

I have an idea, but I want to be sure...

what is the tall bent tube that I see on the hoodof the 550's and some other cars?

Is it a pitot tube? and why?

Thanks

Eric

[Rubinho]

From the description it sounds like it is a pitot tube but a picture would clarify it.

They're used for measuring speed.

[Ericd]

I would pop up a pic but apparently I cant until I have made some number of posts here.

Yes, I know a pitot tube is for measurig airspeed, however I am curious as to the reason to do this. I am sure the data system is measuring speed by tire revolution in the car as well, so is it just for cross reference and error checking?

[MIdsm]

I would venture to guess that it's used to separate aero loads from suspension loads. For example, the team may know that at velocity "x" (true air speed) the vehicle will generate "y" amount of downforce. As teams know spring rates they can use the info to determine how much of the suspesion compression was caused by aero loads and how much by road surface and they can modify damper valving to maximize mechanical grip and keep the car off the bump stops due to aero loads.

This is only a guess.

[Lukin]

Pitot is air speed, not vehicle speed. If there is a wind it will confuse the reading.

Actually, maybe your right. By comparing air speed to wheel speed, they get wind direction. I know when I have tried to compare cars in different aero trim, wind has severely confused me. They probably have a 'wind' factor for drag.

[R59]

Yep, that's the beastie. It's for measuring airspeed. Throw that into your calculations and you can come up with almost any answer you want. 1+1=3
Also useful when coupled with air pressure in the intake for accurate engine managment.

[car1]

If it is air speed it be a computer on the plane

[MIdsm]

Aero loads depend on the true air speed, not vehicle speed. For example, if the vehicle moves at 120 mph and has a 30 mph tail wind then the true air speed is 90 mph. If the vehicle moves at 120 mph and has a 30 mph head wind then the true air speed is 150 mph. Thus if one knows the actual air speed one can use that information in consequent calculations. Direction of the wind does have an effect on aerodynamics as well as speed measurement. Some aircraft have the static pressure ports on both sides of the aircraft and take the average of the two and compare the result to the pitot tube dynamic pressure reading to calculate airspeed (this can be done mechanically/pneumatically). Of course with data acquisition one could measure all three values - dynamic pressure and static pressures on both sides of the vehicle to calculate wind direction too.

[THR]

yea i agree.. to measure wind speed..
ya know on some tracks they take things off or put them on, to allow the wind to pass over the car better, sideways.. cross winds..
barcellona is an example (probs cos they test there so much)

you can feel it in your car as u go past a lorry, imagine wot its like at 120mph with a 40mph gust of wind in an f1 car.