Onboard wind speed measurement?

[ennored]

Aero is all about wind, duh. Just because I'm going 60 MPH, and the the local weather says there's 10 MPH winds doesn't mean I experienced a 50 (or 70) MPH airspeed. Looking at flags or what the grass is doing doesn't cut it.

Has anyone tried an onboard weather station / anemometer? I see mention of folks using pitot tubes here, I looked at them a bit, but didn't find any nice DIY setups.

(Maybe there's a thread somewhere? Search didn't find anything obvious for me.)

[Frank Lee]

Speaking of thread, I think a thread taped onto the hood or windshield would reveal your vector...

[BamZipPow]

I figure one of those storm chasing vehicles would have something of interest to you...

[wmjinman]

I'd want to make sure it didn't add too much drag. A little "tower" coming up in front of the front bumper to a level somewhere above the hood with a "weathervane" and pitot tube might give some info, but at what cost in drag? Guess it would be easy enough to test it.....

[RedDevil]

I'm interested in this too, and wondered whether an analog joystick could be used.
Covered with a thin rubber sheet (balloon?) to keep the stick centered, small foam pipe sticking into the wind. This could measure both force and direction, though some calibration would be needed.

I don't like the cost of commercial anemomenters, maybe this could help.
I haven't looked into pitot meters yet.

[gone-ot]

...a couple things to remember about trying to use a weather anemometer on a car:

1) There's a difference between "cups" and "propellor" wind-speed devices; one's better for lower speeds, other for higher speeds, but neither are 100% accurate.

2) How's your polar-algebra, because, there's a vector diference between car direction and wind direction almost ALL the time...sometimes positive, sometimes neutral, sometimes negative.

3) Wind flow over the car body WILL channel/deflect the actual AIR wind directions & speeds.

4) Lastly, the REAR of the vehicle is where MOST aero drag occurs, so are you prepared to put a second anemomter back there too?

[sheepdog 44]

I've looked into this before. I found some good ones that did 0-100mph wind speeds made for light aircraft. They were $100 or more and not worth it to me.

I wanted to put in an aircraft horizon and altimeter. The grade in the road and elevation gain and loss are more important to hypermiling. There's not much you can do about the wind except slow down.

[bestclimb]

Here ya go

[aerohead]

Originally Posted by ennored

Aero is all about wind, duh. Just because I'm going 60 MPH, and the the local weather says there's 10 MPH winds doesn't mean I experienced a 50 (or 70) MPH airspeed. Looking at flags or what the grass is doing doesn't cut it.

Has anyone tried an onboard weather station / anemometer? I see mention of folks using pitot tubes here, I looked at them a bit, but didn't find any nice DIY setups.

(Maybe there's a thread somewhere? Search didn't find anything obvious for me.)

I attempted a Dwyer panning,source-seeking weather head along with a 0-3" Dwyer Magnehelic in lieu of a fluid manometer.They require damping/restriction as the needle can be all over the place at times.And the head will take in water,so an inline,hermetic water trap is helpful for both ram and static inlets.
Wicks and Aircraft Spruce have some nice low-scale airspeed indicators which would be easier to work with if you can get over the price.

[ennored]

Thanks gang. No easy/obvious answer it seems. My primary use would be on my motorhome, so I don't have a hood to play with, but I do have a large roof. Drag impact should be minimal (is minimal a strong enough word?). I need to check a few links. I could see spending $100. And it's pretty simple math (trig) to figure out the airspeed vs. groundspeed.