Wind Definition and 861 Threads

We are looking to effectivley build a wind turbine to capture the wind and create energy. What would be the most effective and easisest way to construct the windmill? I would like to focus on the design of the blades themselves. What design of the blades would provide maximum support and...

Homework Statement Here's the problem: http://www.flickr.com/photos/38401311@N05/5476715833/Homework Equations Here are the given equations: http://www.flickr.com/photos/38401311@N05/5477319510/ and http://www.flickr.com/photos/38401311@N05/5477320730/ The Attempt at a Solution I really...

Hello. Let me make something clear right away, I don't think perpetual motion is possible. However, whenever I look into wind-turbines/cars I find forums bashing some young person for asking why we don't strap a windmill to the top of our cars. Obviously that wouldn't be an efficient way...

How do i develop a wind turbine model for electricity generation.

Hello, I am designing a rig to measure the rolling moment of a model aircraft. The rig will have a settable yaw, pitch and roll, but only the rolling moment is to be measured. The model aircraft will be similar to an Airfix model. Approx dimensions: L221 x W152. I was just wondering if anyone...

Is there a formula for calculating heat loss due to wind (not wind chill temperature)?

Homework Statement Model a 1KW windturbine. Homework Equations in this link u will find the equation (its equation 2-3) for a fit for a cp(lambda,beta) curve. It has 6 coefficients. The coefficients given are particular to a 1.5 MW windturbine. Does anyone know where I can find any...

Hi, I am again toying with programming and simple flight movements and whilst researching I've read that the angle of attack is perpendicular to the relative wind or flow and NOT an aeroplane wing. But isn't relative flow always in the oppostive direction of the planes direction vector...

I have wondered lately about the amount of energy which interacts with the Earth's magnetic field. Further, to the extent not converted to light as with the auroras, what happens to it in the interaction? If the energy is significant, is it in any way absorbed, transferred or otherwise lead to...

Homework Statement You are on an airplane traveling due east at 110 m/s with respect to the air. The air is moving with a speed 43 m/s with respect to the ground at an angle of 30° west of due north. 1)What is the speed of the plane with respect to the ground? >>> I answered this question and...

hi!... Does anyone know the relationship (i mean formulas) relating to the incoming air velocity to the rpm of a wind turbine?..i need to have a design in the generator part and also the parameters of the propeller..thanks! best regards, :)

I came across a report entitled "Wind Farms Provide Negligible Useful Electricity" by Richard Courtney. You can google it its just available free on the internet. What I wanted to know, if anyone here works in the power grid industry, was it true or should it be taken with a pinch of salt...

Could a small ducted fan / wind turbine say 4 -5 inches in diameter placed in the wind stream of a car develop enough energy at freeway speeds ( or less ) to help charge the cars battery at a realistic level say 30 to 75 amps 12v? I am thinking along the line of a duct from the front grill area...

Ok not a great title, but let me try to explain the idea. Imagine that you have say a parachute attached to the top of a flag pole. In the center of the parachute a hole is cut and connected to a plastic tube that goes to the ground. When the wind comes up the parachute exerts a drag on the...

how do we find the natural frequency of a tower of a wind turbine if, say, the tower is circular hollow cross sectional shape (its not tapered or anything, just cylindrical all the way up). I think i know how to find it when we're ignoring its weight, but what is it when weretaking into account...

Physics tells us that air molecules would cause friction which in turn would make an object hotter. So why do I freeze my :smile::smile::smile: off in the cold when it starts getting windy (while I'm obviously not sweating).

Renewable Energy (RE) Sources are a hot topic, but careful study of the solutions thus far offered make realizing RE as more than a tiny percentage of demand unrealistic. I have been thinking on an idea for a very large scale wind generator that I think is a potential solution for many of the...

I have a basic question on how the power efficiency of wind turbine affected by the gear ratio. Suppose there is a generator connected with the rotor through a gear enhancer, a higher angular speed of generator is obtained. Since a higher voltage is produced, we may think that the power...

Hello. I was wondering about something the last few weeks and that is if the solar wind can affect communication systems between satellites. I am not referring to the physical damage that the solar wind might produce to the satellite, but the interference it might have on the radio signal that...

Building a wind simulator. Control amount of electricity?? I have about 20 6" fans that i'd like to mount to something in which I can control electricity to each fan and essentially simulate wind. I looked at light DMX controllers for DJ's and that would be perfect except the electricty...

Greetings, I'm seeing programs that allow solar, wind and other types of power generation to be connected to your house (or business) and you are still connected to your grid. The power company meters both - what they provide to you and what your private generation provides. Your power...

I'm a beginner at this but I'm an aspiring student of the electrical field. Electrical engineer, electrician, electronics technician. I like it all. My question is what equipment, other than what I know already, do I need to run as much of my house off of wind power? Wind turbines or...

Whenever I see a wind farm, a huge proportion of the turbines just aren't going round. I don't mean in a flat calm, either. Why aren't the stationary ones doing their stuff? What were they put there for? I have a theory that politicians feel that they understand the wind (they are full of it...

Hi, I'm having a little bit of trouble. I need to work out the amount of energy the wind provides at an average speed of 2.67m/s when the blades of a turbine are 0.5m in length? Also how would I use this energy in order to calculate the size of a reciporacting pump needed to pump a head of water...

Homework Statement An airplane has a speed v and a flying range (out and back) of R in calm weather. (a) Prove that in a north wind of speed n (n < v) its range is R(phi) = R(v^2 - n^2) / [v(srqt(v^2 - n^2 sin^2(phi))] in the direction whose true bearing from north is phi (Assume...

Homework Statement A plane has a max airspeed of 770m/s. If the wind velocity is 150m/s 48o W of S, in what direction and with what velocity should the pilot fly the plane to have a ground velocity of 640m/s at 57o E of S? Can She do it? Homework Equations V(plane to wind) + V(wind to...

how would i go about finding the torque that wind turbine blades would produce with my wind conditions, for example 8' diameter blades at 10 mph wind?

Hi Guys, I understand that the energy associated with wind damage from a hurricane goes as the third power of the velocity of the wind. How is this relationship derived? I ask because when I think of wind energy, I think of Kinetic Energy going as the square of the velocity...

When Obama first proposed the economic stimulus, I raised a BS flag here, saying that you can't just start handing out checks and bridges and roads will start being built immediately. It takes years to design a major project. Even a supposedly "shovel ready" project (one completely designed...

Homework Statement Air in a 140 km/h wind strikes head-on the face of a building 60 m wide by 50 m high and is brought to rest. If air has a mass of 1.3 kg per cubic meter, determine the average force of the wind on the building. Homework Equations The book seems to suggest the impulse...

If temperature gradients cause wind in air, how about in zero gravity?? Hey guys, I'm aware that atmospheric temperature gradients causes changes in bouyancy so hot air goes up and cold air goes down and immediately fills in the 'void' the hot air left, thus causing wind. What about in...

I really need help in my undergraduate thesis which focus on wind energy. Goal I want to calculate the amount of Power in the wind turbine shaft, which later used to calculate the efficiency of my wind turbine. Material My wind turbine uses 3-blade household common fan as blade which have...

Hi physics peoples, [for the tl;dr peeps: is there any point plotting a force distribution when I already have a pressure distribution, aren't they essentially the same thing?] I've been doing wind tunnel experiments on structures for my final year engineering project, my supervisor (who I...

The original mass is 25.5g. The mass(G) we got were: 23.4 mass(g) - 7.7 Air speed(km/h) 22 mass(g) - 9.7 Air speed(km/h) 20.3 mass(g) - 12.1 Air speed(km/h) 19.2 mass(g) - 13.5 Air speed(km/h) 18.35 mass(g) - 13.7 Air speed(km/h) I needed to find the lifting force and the Speed in m s-1 So...

Homework Statement An airplane flies 142 mi/hr with respect to the air. On this day, the air is moving at 52 mi/hr due north with respect to the ground. What would be the velocity of the plane with respect to the ground,vpg, if the plane were pointed in each of the following directions? How...

Hello all. I have a question about a wing model... The model I have is an airplane wing (airfoil) in a wind tunnel. The wing is supported at the quarter-chord length and the wing body is free to move. My model is in the time domain with an oscillatory force at 20 Hz applied to the wing...

I was talking on another forum about an idea someone proposed. They said if you put a miniature wind turbine as a Hood Ornament on a car, as the car drives, it would produce extra usable energy. I said this would not work as if the wind is not blowing at the correct angle and velocity then...

There was and still is a hot debate on the matter of a wind power car that travels down the wind faster than the wind. As a part of larger interest in the subject I put the theory for this case, it can be found in my website https://sites.google.com/site/yedidianeumeier/" I welcome your comments

hi friends, i came across this piece of news... "Until 2010, no solar sails had been successfully used in space as primary propulsion systems. On 21 May 2010, the Japan Aerospace Exploration Agency (JAXA) launched the “IKAROS” (Interplanetary Kite-craft Accelerated by Radiation Of the Sun)...

Hi there, There is a question of text about a sailing boat and the force of wind. Suppose the boat is directed downwind as shown in the image. I think for fluid, the interaction force on a smooth surface is along the direction perpendicular to surface. Hence, force F is result from the...

Hi guys, I am working on designing a wind turbine spar for a second year mech project. The spar has an elliptical cross section, is hollow and linearly tapered with a linearly varying wall thickness. The entire tower reaches upwards at angle. My question is: if I want to find out the...

Hello, Im new to the forum, i joined to ask a question about a boat I've been obsessing about for awhile. My idea is an aluminum sail boat (27-40') that has its mast removed and replaced with say a 3-4kw vertical wind generator (350lb) i know that's a bit heavy but I am sure the wind forces are...

Hey, I have to design a test rig for my university's wind tunnel. The test rig is required to measure lift, drag, pitch moment and rolling moment. The professor has asked me to keep the budget around 2k. I was looking online about what is available and came across 2 types of balances...

I am working on a spreadsheet for designing a small footing to support 1-4 Radiation Portal Monitors (RPMs). These are vehicle scanners weighing in around 2-2.5 kips a piece and roughly 7.5'Hx3'Wx1.5'D. they are arranged on the footing in a few different configurations. aside from the self...

Hi there... if it is of interest to anyone. I just completed a wind turbine blade design and simulation software fully integrated into the GUI XFLR5 of Mark Drelas XFOIL. If you want to try it out check: qblade.de.to cheers David

hello. i need to match electric motor to propeller/fan to my outdoor aeroduim wind tunnel. my requirements goal is to get a 2.00 meter diameter propeller with 190kh wind speed . which electric motor (type,power) would you think will properly match for this requirements ? thank you.

Homework Statement Explain if wind on walls and roofs of buildings is considered a pressure or a force? Homework Equations P = F/A The Attempt at a Solution Wind load should be measured in terms of pressure?..but I don't know the exact reason why it is. Does it have something...

Homework Statement A small airplane flies at a velocity of 145 km/h toward the south as observed by a person on the gound. The airplane plot measures an air velocity of 172 km/h south. What is the velocity of the wind that affects the plane? Beyond knowing the velocity of both the plane and...

anything big like it costs more then 15 million and some how it has made or is attempting to make a significant contribution to the field of physics. If it's happening in Canada then that would be most preferable and helpful but if it's taking place in a different country then that is good too...

Not 100% certain this is the best place to ask this question, though I've asked questions here before, and there seems to be some smart and helpful people here. I was pondering wind farms and thinking about T. Boone Pickens' idea of huge expansive wind farms to generate energy. Apparently the...