Author Topic: measuring /logging air speed ?  (Read 10325 times)

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Offline Glen

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Re: measuring /logging air speed ?
« Reply #15 on: February 12, 2010, 02:25:11 PM »
We use a airspeed ind. on the Turbinator streamliner.
Glen
Crew on Turbinator II

South West, Utah

Offline wrongway

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Re: measuring /logging air speed ?
« Reply #16 on: February 14, 2010, 09:31:13 AM »
here is the first test , logging gps speed and air speed. This was on the car going down the interstate last wednesday when the wind was gusting to 30 mph.



Roy

Offline bbarn

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Re: measuring /logging air speed ?
« Reply #17 on: February 14, 2010, 09:37:06 AM »
Roy - I assume the Series 1 is the GPS and series 2 is from airspeed?
I almost never wake up cranky, I usually just let her sleep in.

Offline wrongway

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Re: measuring /logging air speed ?
« Reply #18 on: February 14, 2010, 10:34:35 AM »
yes ....series 1 is gps speed

Offline RansomT

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Re: measuring /logging air speed ?
« Reply #19 on: February 14, 2010, 11:44:35 AM »
here is the first test , logging gps speed and air speed. This was on the car going down the interstate last wednesday when the wind was gusting to 30 mph.



Roy

What are you using to measure air speed?  What voltage range?

Offline wrongway

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Re: measuring /logging air speed ?
« Reply #20 on: February 14, 2010, 01:13:35 PM »
i am using a homemade setup , logging thru the USB onto my laptop.  The airspeed sensor doesn't have an analog output, but this setup allows me  to log GPS coordinates and speed also. hoping to have a standalone setup done by the april race.

that is why I was asking what others were using ,,, so I would not have to build something. But I didn't get any real info from anyone.

Roy

Offline robin dripps

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Re: measuring /logging air speed ?
« Reply #21 on: February 14, 2010, 03:40:42 PM »
You might look into air speed sensors readily available for sailboat racing.  These are pretty sophisticated devices able to deal with wind direction, wind speed, vehicle speed, barometric pressure,  etc.  There might be an issue with the speed differential between a sailboat and an LSR but possibly worth a look.
robin

Offline bbarn

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Re: measuring /logging air speed ?
« Reply #22 on: February 14, 2010, 08:04:11 PM »
Also check White Industries in Kansas. They are a bone yard/salvage shop for aircraft. You may be able to get a good deal on a serviceable but not airworthy unit.
I almost never wake up cranky, I usually just let her sleep in.

Offline RansomT

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Re: measuring /logging air speed ?
« Reply #23 on: February 15, 2010, 03:56:14 PM »
I know (now) that they do make electonic aircraft speed sensor ... wonder if one of those will work?

Offline RansomT

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Re: measuring /logging air speed ?
« Reply #24 on: February 17, 2010, 02:07:09 PM »
and while researching this, I found this sensor.

http://www.eagletreesystems.com/Standalone/standalone.htm

Offline manta22

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Re: measuring /logging air speed ?
« Reply #25 on: February 19, 2010, 03:39:44 PM »
Dwyer Industries sells small pitot static tubes; run the two output lines into a sensitive differential pressure sensor; its output will then be proportional to the airspeed. Remember that it is nonlinear, though!

Regards, Neil Tucson, AZ
Regards, Neil  Tucson, AZ

Offline A2WindTunnel

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Re: measuring /logging air speed ?
« Reply #26 on: July 20, 2010, 02:36:02 PM »
Remember that the Pitot tube must be in a location unaffected or the least affected by the streamlines.  Here are some pictures of a Cup car instrumented with a Pitot and Yaw probe to give you an idea of location.  The yaw comes from the wedge shape with a left and right channel.  As air comes to the front of your vehicle it will slow down in the front and the point at which the air will “stop” is the stagnation point (in blue CFD picture).  You DO NOT want to put a pitot tube in that location, but rather in free stream as far away from the surface of the car as you can get away with.  The Cup car in the 2 lower pictures has it located about 16-in away from the top of the roof. In the CFD below you can see that to be totally unaffected by the streamlines you would have to have the Pitot tube very far away.

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Offline 1212FBGS

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Re: measuring /logging air speed ?
« Reply #27 on: July 20, 2010, 04:28:46 PM »
  As air comes to the front of your vehicle

I always thought your car comes to the air!

kent

Offline Peter Jack

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Re: measuring /logging air speed ?
« Reply #28 on: July 20, 2010, 04:47:15 PM »
Not in a wind tunnel Kent. :evil: :evil: :-D

Pete

Offline A2WindTunnel

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Re: measuring /logging air speed ?
« Reply #29 on: July 21, 2010, 08:19:33 AM »
Quote
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.. 
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