Wind Definition and 829 Threads

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...

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...

I'm a high school science student/aficionado (since it's sort of hard to specialize in anything in high school) and I have some relatively elementary questions: I learned in chemistry class that temperature is the average kinetic energy of the particles in any given sample of gas, so...

Homework Statement A wind is blowing at 25 km/h from the direction of 270 degrees . Find the magnitude and direction of the velocity of the wind relative to a cyclist traveling at 20 km/h in the direction of 120 degrees . Homework Equations The Attempt at a Solution Using the...

my dessertation topic is optimum wind turbine blade design with xfoil. and the aim of this project is to find a series of airfoil that gives a good efficiency and also how the angle of attack changes with rotation...pls has somebody got an idea about...and also how best can i start this...

What do Cape Wind and nuclear power have in common? Opponents come out of the woodwork to oppose both and there is no regulatory framework in place to limit the challenges for either. As a result, opponents can litigate the projects into oblivion. Case in point, Cape Wind. It is currently...

Consider a wind turbine placed alongside a road in a location with no wind. If a vehicle drives past (without loss of generality, at a constant speed) the turbine will spin and electrical power can be produced. The power produced is obviously supplied by the vehicle. As compared to the case...

From the little bit I've read online it seems like wind and solar have the most potential. Also, can you get student loans if you are unemployed? (I have a good credit rating and I'm in the US)

The wind power that is generated using the wind mills in a wind tunnel like the crowsness pass can't be constant. How can the amount of wind be counted on because with gloabl warming maybe wind will not be as often in the future?

Homework Statement A baseball is hit with an initial velocity of 103 ft/sec, with an initial height of 3 ft, and at an angle of 41 degrees. There is a wind blowing 22ft/sec in the direction opposite to the horizontal path of the ball at an angle of depression of 12 degrees. Assume that gravity...

Hi, I'm currently trying to design a wind turbine for a college project. I know the ideal equation for power is (mass x area x velocity cubed)divided by 2. Is there anyone who could help with equations relating the power output to the number of blades and angle of the blades. Thanks

Hello. I'm calculating the different parameters of a turbine design but I have some trouble with the solidity. The solidity near the hub exceeds 100%, but is an average of ~27% for a 6 bladed turbine. I'm just wondering if anyone has had experience in turbine design and if +100% solidity is...

Hey guys I got a thought question. When air is moving, it is said that they have a higher kinetic energy than still air. Thus, the temperature of moving air should be higher than still air right? But then sometimes on a hot day why does the wind make us feel cool? I know there's hot wind but...

Here's the problem: An airplane is flying on a bearing of 340 degrees at 325 mph. A wind is blowing with the bearing of 320 degrees at 40 mph. a) Find the component form of the velocity of the airplane. b) Find the actual ground speed and direction of plane. I can find the component form...

Hi friends I am a mechaincal engg. student and I asked yesterday my professor of fluid mechanics that there should be a educational wind tunnel in our laboratory to understand concepts of streamlines, lift and drag better and visually. He replied me with a challenge that I should make such a...

1. Wind turbine produces 8MWatts (If wind speed is proportional to the 7th root of altitude) (Wind power is proportional to the cube of wind speed First the turbine is at 450ft then reconstructed at 650ft, how much faster is wind speed? and how much more power?2. Sw= 7√Altitude, Pw= (Sw)33...

Up until middle school.. math was my thing. I wouldn't say I "enjoyed" it, but it definitely came naturally. My teacher even forced me to do math counts in 7th and 8th grade. We had a grad student as our coach and he always tried to get me into math, and, for whatever reason, I just really...

Hey, I have a question pertaining to the effect of wind resistance on a 0.2 gram plastic, spherical airsoft bb over a given distance. I know it has something to do with drag coefficient, and I’ve been having a little trouble calculating it myself, so I would really appreciate any ideas and/or...

Homework Statement A car leaves point A and drives at 80.0 km/h [E] for 1.50h. It then heads north at 60.0 km/h for 1.00h and finally [30o W of N] at 100.0 km/h for 0.50g arriving at point B. a) Determine the displacement of point B from point A. b) A plane flies directly from point A to...

Hi! I’m a 4th year student at mechanical engineering. I have been asked to design a kit that can be installed in a car/vehicle which can be used to recharge the car's battery or connected to some of the car's/vehicle's component to power them. Where and how do I start? Does anyone have a...