Localized aerodynamic flow checking

[Joenavy85]

I am now

[Bill in Houston]

Originally Posted by Joenavy85

I am now

glad i could share.

[diesel_john]

how about a turn table large enough to set a vehicle on. like an old single cylinder car lift. so, I can sit out in my field and turn the vehicle into the wind at what ever angle i need. the weather channel is getting pretty good at predicting the wind.

[Floordford]

Hahaha, my fault. 30".

Originally Posted by diesel_john

how about a turn table large enough to set a vehicle on. like an old single cylinder car lift. so, I can sit out in my field and turn the vehicle into the wind at what ever angle i need. the weather channel is getting pretty good at predicting the wind.

That inspired a interesting idea in me. A car trailer. It would be super easy to put a car on a car trailer behind a truck with no tail gate to get an idea of some areas. Granted you'd need to do it with no cops around if you planned on being on the trailer. But thats about as low budget wind testing as it gets. Probably as close to real world as it will get.

[MechEngVT]

Several years ago there was an article posted on the web site of an Australian car magazine that does a lot of hands-on how-tos and more science-related stories...wish I could remember the name of the rag. They had a fairly low-cost setup that used a small pressure switch and a digital multimeter that would beep when it detected continuity. The switch would be taped to the car in the area where they wanted to check the pressure buildup and wires ran inside to the DMM where the driver would check the speed on GPS or the speedo when the DMM beeped on detecting continuity. The switch would close at a given pressure setting, so the trick was to measure the vehicle speed at which the pressure grew enough to close the switch. Making aerodynamic improvements increased the vehicle speed required to close the switch.

[Bill in Houston]

autospeed is the magazine.

diesel john, i love the car-as-weather-vane idea.

[aerohead]

If you'll rent the movie 'Tucker,the man and his dream',there will be a scene where aerodynamacist and design chief,Alex Tremulis is blowing air over a model of the Tucker Torpedo with a household fan to check flow.

[slime]

Some of that could be done with yarn tuffs taped to the areas you want to check. There are a few lower cost cameras that you could use to watch these areas (if you can' be mount see them from the cockpit) GoPro is one. You might be able to do this with a really strong leaf blower too if you just want to check smaller areas.

[California98Civic]

Originally Posted by Bill in Houston

Is anyone else thinking of that movie, "This is Spinal Tap"?

I am now! Visions of Stonehenge...

[Otto]

Localized flow with a leaf blower is better than nothing, but still lacks insofar as what happens on the road is both general and local flow. So, the area you blow may not necessarily flow that way on the road.

Bits of yarn and tape is cheap and easy, or do streak tests with dabs of dark oil or water-based tempura paint, see what happens at highway speed, then wash off. A chase vehicle with short digital videos, operated by a friend, would tell the tail.