Wind Speed Indcator Design

[DOC]

I am a Sixth Former and I am building a Wind Tunnel for my A2 project. I need to build an electric wind speed indicator with an analogue gauge and it has to be non mechanical. Have you got any ideas how I might go about doing this?

 

[Nigel Goodwin]

As far as I know, the only non-mechanical method is ultrasonics?.

Have a look at **broken link removed**

 

[ericgibbs]

I am a Sixth Former and I am building a Wind Tunnel for my A2 project. I need to build an electric wind speed indicator with an analogue gauge and it has to be non mechanical. Have you got any ideas how I might go about doing this?

hi,
You could consider a Pitot tube and pressure sensor.

HENRI PITOT TUBE SPEED MEASURING INSTRUMENT | DANIEL BERNOULLI'S LAW FLUID FLOW AIRFOIL LIFT

 

[KMoffett]

Google: hot wire anemometer...or...thermistor anemometer...or...pitot tube anemometer

Ken

 

[MrAl]

Hi,


There is also another type of non mechanical flow meter, and
that is the measurement of the ability of the flow to cool a
device that is intentionally heated.

The principle of operation is basically simple:
A device that is internally heated by an electrical current will
reach a certain temperature in still air, but in a flow of air
the device will cool off because the air flow sweeps away
some of the heat at the surface. The most common type
of device that uses this principle is probably the ordinary
heat sink, used to cool semiconductors.

Of course there is a little more to it than that, because the
rate of cooling also depends on the air temperature, so two
devices are used: one inserted into the air flow, and the
other not inside the air flow, and the two measurements are
compared to get the final reading. The devices used are
typically some kind of semiconductor whos characteristics
are well known.

Unfortunately i dont have any links right now, but there
may be an app note on the National Semiconductor site
somewhere, or a search on Google might turn something up.

 

[ericgibbs]

hi Al,

As you say with a heated element, often a bead thermistor, a second thermistor enclosed in a heated oven is required.
The oven has to be kept a stable temperature quite a few degrees higher than the external sensing bead.
Of course, with requiring a stable tempr oven it means tempr sensing and heat control for the oven.. warm up times etc....

The beads are in a bridge configuration

 

[Mikebits]

I am a Sixth Former and I am building a Wind Tunnel for my A2 project. I need to build an electric wind speed indicator with an analogue gauge and it has to be non mechanical. Have you got any ideas how I might go about doing this?

How did you get into this bind? Your easiest solution would have been a propeller driving a generator.

Maybe a bribe will change your instructors requirement

 

[MrAl]

Hi again,

Eric:
Ok sounds good. I dont remember any of the design offhand as it's been
years since i looked at this stuff.

Mike:
That's a good idea and one that i would certainly try adding a vane and
shaft to allow the prop to follow the wind direction naturally. Nice.
Thing is, this OP specified *non mechanical* so that's the reason why
all of the replies so far have not included things like generators.
Heck, i'd even go for a rotating prop with an ir beam to measure
frequency...i've done this before for checking the speed of ac fans,
but that's mechanical too.

 

[KMoffett]

Some theory:

**broken link removed**

And some real world circuits info:

Thermal anemometer

Ken

 

[Externet]

I do not know what A2 means.
But you can obtain the device for nearly $0 at a wreck yard, it is used in most modern automobiles at the intake manifold. Measures air mass flow, no moving parts, by temperature differential as explained in above posts; tells the computer how much fuel to inject.
The parts can be installed on a larger scale wind tunnel, and depending on its output, you may hook a 0-to-5V meter or a frequency-to-voltage converter chip to move your analog meter.
Miguel