Wind Tunnels

If you are only testing the air, it should be good; but if you are testing the material, you probably need the tunnel.

no materials, just the movement of air into and out of a funnel.

That Santa Ana wind phenomena and a suitable vortex may suffice with addition of an articulated air dam.

Hi Spacecannon,

The cost of your tests is important so that questions should be answered before you do them.

1- Do you need from the start the tests be done at the scale you mentioned? Many tests start with down scaled models till an optimum has been reached so that the request for full scale or less down scale models become imperative. Up to a point even a table model can be used at a much lower cost. Depends on what you want to optimize. For instance blade profiles can be analysed with models of about 4" chord x 6" length and with help of similitude laws used at much more important dimensions

2- Do you want to analyse the duct or what will work in the duct? As well in the 1st as in the 2nd case what is needed is a source with a straighter in front (how it was recommended in order to avoid rotational flows) and the possibility to measure the parameters you want to analyse and compare. I would give to the straighter design a very high attention since the results quality will strongly depend on its quality.

3- A real wind tunnel is required especially when you want to recirculate the air for which ever reason.

4- Could it be considered a first attempt to optimize "on paper" using existing packages for fluid dynamics before making real life tests even on reduced models?

An hour simulation will cost a few hundreds and not 5k$! I think from the outside and not knowing all details that the approach simulation + down scaled model + full scale model will be the optimal fom time and cost point of view.

Existing soft gives results VERY near to the final lab tests.

Nick name, thx for your help,

1) the scale I mentioned of 10'x30' is a 1/10 scale, and since I'm measuring the air flow itself I was concerned about the density of the air affecting the compression in the funnel. If it is your opinion that I could go to a 1/30 - 1/100 scale with out the viscosity throwing the numbers off then this could save me alot of money. However all the research done so far have used 4'-6' diameter models.

2) just want to analyze the air moving into it and out of it, of course a straightener is needed.

3) don't need to recirculate the air at this time.

4) I would like to do CFD analysis if I could afford it, in order to narrow the range for actual testing.

The $5k/hr cost was quoted to me by the division cheif of the big wind tunnel at Moffet Field, (Ames National Lab).

I would love to do CFD analysis, do you know anyone cheap, I'm currently checking with some Universities.

I am far away (as you can see from the name of the town I live in) but I shall try to be of help.Never the less I shall contact some body who could may be want to do some thing. Keep you informed. Any way if he agrees you can be sure that all will be considered as totally confidential.

Nick

Awsome, thx, GA. I will see if I can get my home page working so you can see what Im talking about, what e-mail do you want the link sent to?

Aurizon,

Simple and brilliant. GA

Can you not just set out your model on a rotating footing on top of a suitable pillar located in the open where there are prevailing winds, orient (automatically with a rudder on the footing or manually guided by a weather wane) to the wind and make your measurement of pressures? Correlate this with anemometric measurements of the wind velocity outside. You can also monitor the velocities along your model. There is no need to have an external structure as you are investigating what goes on inside your model. There are enough analytical models available for simple air flow through venturis and such profiles. You can minimize experiments by simulated tests first. Also 10' x 30' seems very large for a model. 10" x 30" may suffice.

Bioramani, we originally thought about doing it that way but, time is forcing us to shorten the duration, so the need for man made wind.

Solidworks has recently announced an addition to its 3D CAD program called 'Flow simulation'. You might contact an experienced Solidworks user and see if it makes economic sense to simulate measurements of your wind turbine with that program.

Good day Spacecannon

Just a quick question. What is the wind turbine intended for? Generating electricity or some thing else? There are may apps for them and each app has particular "preferences" as to design. I spent many years developing different designs all around using wind (and other) energy for a variety of uses. So shoot, lets see if we can help you.

Good day Guest,

Its for power generation. Let me talk to my patent lawyer before I say much more.

I agree with Aurizon's comments about using a squirrel cage blower and a tabletop model. If you feel you absolutely need a large 10 x 30 foot model, given your rural location, can you not rent a flatbed trailer and tractor to pull it through the air at whatever range of air speeds you wish to test? I assume 10 feet is the input aperture and 30 feet is the cone length?

rcavictim

Guest-rcavictim,

yes those are the approx. ratios and is 1/10 scale, I'm afraid to go smaller because air density could affect experiment outcomes.

You said : "what I'm modeling is the inside of a funnel (...shaped more like a snow cone laying on it's side)...researching the winds ability to compress itself on surface or in a container"...

Sounds to me as if you're trying to reinvent the wheel.

Guys like Bernoulli (also see this: Bernoulli vs Newton) and fellows such as Boyle, Charles, and Avogadro have laid-down the principals in such excruciating detail that the modeling which you seek to perform (I suspect ... ... admittedly, without going through the motions myself) could be performed by a couple college physics majors with very little effort ; perhaps for as little as a weekend's worth of pizzas and beer.

Don't be embarrassed to stand on the shoulders of giants...!

Nick name,

Its true that this particular experiment hasn't been investigated enough mathematicly and that there seems to be no clear math model to choose from. However I am extrapolating my work from giants, Ozer Igar's shroud experiments, J Werle Michael's ducted wind investigations, Fan wangs scoop study and meny others. I call it a funnel because mine is more extream in the dimensions and ratios.

Hi spacecannon

I had to save cost for a wind tunnel a few years back. Mine was a different problem, application but was related to wind speeds as well. I set up my "Box" on the back of a V8 ute (pick up truck) and had it driven at high speeds 230kmh to imitate strong winds. In your case you might need a semi trailer to fit your equipment on. This will give you the chance to test while being able to govern the wind speed at the same time.

This suggestion could be way off but would be cheaper than a wind tunnel, much cheaper. I am not sure what speeds you are looking at but you have the Mojave Desert not far from you and would not endanger any body while going full bore.

Hope this helps and good luck, Ky.

I would build a smaller model and mount it on a frame upper forward of a car / truck and drive it with instrumentation and manometers on a flat lake bed somewhere.

Small mounting compensation errors and reynolds numbers can be accounted for.

CALTECH in Pasadena where I used to work has a wind tunnel maybe it is inexpensive since it is a University.

Maveric Manic, I believe that wind tunnel was demolished last may.