Wind Definition and 861 Threads

It's been a while since I've been in the classroom and I'm having trouble figuring this one out. I'm trying to create a wind turbine and I need to calculate the size of the prop needed to power and electrical generator. For ease of numbers let's say I'm using a 2800watt generator...

It seems to make intuitive sense for cloud movement to be dependent on wind, but is it actually true? Isn't the Coriolis Force a bigger factor in cloud movement?

Hello! :smile: I have one mysterious question. I have room 25 m2, and I want to made draft, by opening one window and my door to be closed, so I will have closed space with only one window open. What is actually draft? Is it same with wind? Draft = circling of hot and cold air? Thank you.

Hello, I have been trying to find recent developments for wind turbines (post 2000) but so far haven't been successful. Does anyone have any ideas as to any recent developments that have occurred (even if you arn't sure, just some ideas that I could research)? thank-you!

Nope. I'm still having trouble. I asked about this before, but it's still not gelling for me. There's a wind turbine on the "front lawn" of the city of Toronto that I pass every day. Its blades are never more than ~20 degrees from flat, i.e the blades are almost perpendicular to the flow of...

Dear all, I'm just doing some thinking around the maximum theoretical power that can be extracted from wind by using a wind plant. Derivation of the power inside a block of wind is not difficult then I'll simply report some consideration regarding this subject (look at the attached paper for...

can anyone explain to me wad is the angle of projection of a projectile motion for the longest range with wind resistance?

http://bash.org/?131553 lol :D

Hey guys, so for my extended essay in physics i hav came up with a topic that required me to build a wind tunel. I already have that, but then now i need to make smoke or sumthing to pass through the wind tunnel to show the wind patterns and variations. Any ideas in how to create sumthing...

1. Suppose we have a tower at seaside (with length L) under a constant speed of wind. Let's assume the force is constant. If we took the drag force equation, only serious variable here is the speed of wind and for a specific time frame let's say for hour or few hours, wind speed and direction...

Im looking for information regarding wind turbines. A 1.5 megawatt turbine rotates at 20 rpm and requires 338 kiloNewton meters of force. A 100 kilowatt turbine rotates at 60 rpm and requires 19.4 kiloNewton meters of force. Both are gearbox driven generators. Is there a formula that is used...

Wind power is a force of nature and it has been used for centuries like for Dutch Windmills. Permanet magnets are a force of nature which through innovation have now been produced so well that they can now hold up to 500 times their own weight. That is a lot of power. The only...

There is a lot of talk about big projects to gather energy from wind. I have two ideas I don't see used that I was wondering about. 1. Using large stretches of canvas to redirect wind from a large cross sectional area to a smaller outlet, like some kind of wind nozzle. It would also form...

Hi everyone, I live in Chengdu, China where as many of you may know suffers a terrible earthquake aftershock nowadays. But during every aftershock there's always a wind blowing from nowhere. I wonder why? Many of my classmates & friends notice this as well. Are there any scientific explanations?

Hi I've a wind turbine which have to run under a very low wind speed, from 2-3m/s. Currently, I'm using Envirotek V20, the result is around 1.5V-2.5V, and current is 0.3mA or nearly zero. My aim is to achieve 50W. Any suggestion for the alternator which I should use? p/s: without...

Hello :) I am currently in grade 11, in Australia. I have an assignment to be completed in the wind tunnel, where we could choose any topic we liked. We also needed to write a full report on it. My lab partner and I decided to construct a rig for a discus (Sporting implement), and measure the...

Homework Statement Hi, i have 2 past exam questions that i need to be able to solve for my exam in 3 days time: consider the portion of a stellar wind of mass density rho, pressure p, temperature T and velocity v between the radii r=R_i = 10R_* and r=R_o = 100R_* where R_* is the radius...

Homework Statement Hi, i have 2 past exam questions that i need to be able to solve for my exam in 3 days time: consider the portion of a stellar wind of mass density rho, pressure p, temperature T and velocity v between the radii r=R_i = 10R_* and r=R_o = 100R_* where R_* is the radius...

I have few question about wind turbine and its theory for the situation, the average wind velocity is 2m/s 1. what kind of vertical wind turbine is the best for the design? helix, Darrieus, "S" shape? 2. for a wind turbine, how to increase it's output current? 3. what is the...

If I know the force that a wind is exerting on an object, is it be possible to determine what velocity the wind is moving at? I also know the air density.

I have to construct a wind power generator out of straws. It has to provide no less than 3V and .2W for a period of 1 minute and be able to withstand a horizontal force of 15N. How would I determine what size the rotor would have to be to create this voltage and current from 15N ?

I understand very little of aerodynamics. Currently, my high school robotics team is designing a F1 model. Concerning aerodynamics, how do you use the Bernoulli's Equation regarding the design of the model car?

I need to make a wind tunnel of plywood for testing a plate fin heat exchanger . the exhaust from the engine is fed through the Wind tunnel and then to the heat exchanger. the heat exchanger of 60 cm in length and fins of 15cm*15cm are welded over it.the temperature of exhaust is around 500'c...

I want to add a secondary battery bank to the hybrid and have that send a charge to the primary battery. I am considering 2 wind turbines mounted in the radiator inlets. I want to have the turbines charge a secondary battery that will feed to the primary battery. I am doing this to...

A sailboat is traveling east at 5m/s . A sudden gust of wind gives the boat an acceleration=.80 m/s^2, (40 degrees north of east). A. What is the boat's speed 6 seconds later when the gust subsides? ________m/s B. What is the boat's direction 6 seconds later when the gust subsides...

Does anyone know of somewhere I could find some documentation on how to create a wind turbine?

Homework Statement A siren mounted on the roof of a firehouse emits sound at a frequency of 900Hz. A steady wind is blowing with a speed of 15.0m/s. Taking the speed of sound in calm air to be 343m/s, Find the wavelength of the sound a) upwind of siren b) downwind of siren...

[SOLVED] Force Problem The total mass is 2300kg (weight = 5072lbs). Find the size of the force due to wind and rolling friction when the van speed is 42.17mph (1mph= 0.447m/s). This is the graph: http://capa-new.colorado.edu/msuphysicslib/Graphics/Gtype12/prob09a_1004minivan.gif" F = ma...

In my astronomy class we have been talking about the solar wind, and how during the solar maximum when the activity is high the solar wind increases and can penetrate into the magnetic field more. This penetration can disturb satellites and even some things that are on the Earth's surface. So...

[SOLVED] The Angle of the Launch of a Rocket against a Strong Wind Homework Statement A 1210-kg rocket is launched with an initial velocity v = 85 m/s against a strong wind. The wind exerts a constant horizontal force F= 8650 N on the rocket. At what launch angle will the rocket achieve its...

A windmill power generator converts a fixed fraction of wind energy into electrical energy.. Supposing the wind falls on the windmill at a speed v...[wind speed=v] What is the total electrical output proportional to..? 1.v^2 2.v^3 3.v 4.v^4

Homework Statement iam doing an assignment on renewable energy, specifically wind power. basically, i wish to know what are all and any principals, laws and theories that you can think of involved in this system. i just wish to know the names, i can do the research (no matter how difficult or...

[SOLVED] Aeordynamics, drag, wind resistance - table with Cw values for objects Hello I am not using the standard template as this is a minor question in relation to my assignment, and not the actual questions from the assignment itself. I am calculating the curve of a projectile fired at...

Hello! I'm doing a research work about projectiles and i thought of crossbow system. I am currently studying using these articles: http://ciencia.hsw.uol.com.br/framed.htm?parent=crossbow.htm&url=http://www.stortford-archers.org.uk/medieval.htm and...

http://www.guardian.co.uk/environment/2007/dec/10/politics Thousands of new off-shore wind turbines could power every home in Britain by 2020, the government will say today, as it announces new wind energy plans. John Hutton, the secretary of state for business, enterprise and regulatory...

I would like to understand the "standard" explanation for the acceleration of solar wind particles as they leave the solar surface. Could someone help me out? I'm specifically interested in explaining this sort of image from the European Space Agency...

If the wind speed is 5m/s at 10masl. How can i calculate the wind speed at 88masl with a surface roughness coefficient of 0.3? Cheers

Hi everyone. I am having extreme trouble finding the answer to this problem. I thought I originally had it, but nope. The original Q is: "Assume a wind turbine with a hub 50 meters above the ground, a rotor diameter of 65 meters and a wind-conversion efficiency of 25 percent. The turbine...

can anyone give me the flux of solar wind reaching earth...the number of electrons/protons /cm^2/sec reaching Earth from Sun...i searched many sites but couldn't get the value...

I've scanned some literature, but could not find a description of the mechanism that causes the "thin vertical wind"* from the accretion disk of a quasar. Can someone please explain or point me to an accessible paper? *Elvis M., 2000, Astrophysical Journal 545, 63

I took a recent flight from LAX to SFO on an Airbus 319 and noticed that there was a lot more turbulence than normal. So much so that the plane had to fly at its service ceiling, and even then, there was a good amount of shaking. I even had a mini panic attack and had to call a flight attendant...

Homework Statement The graph shows the speed as a function of time for a minivan, coasting on neutral along a straight, level road, loaded with windsurfing equipment and towing a boat.The total mass is 2450kg (weight = 5402lbs). Find the size of the force due to wind and rolling friction when...

Homework Statement The posture of small animals may prevent them from being blown over by the wind. For example, with wind blowing from the side, a small insect stands with bent legs; the more bent the legs, the lower the body, and the smaller the angle . The wind exerts a force on the insect...

1. Jane, whose mass is 49.0 kg, needs to swing across a river filled with man-eating crocodiles in order to rescue Tarzan, whose mass is 80.0 kg. However, she must swing into a constant horizontal wind force F on a vine that is initially at an angle of with the vertical. (See Fig. P5.73.) In the...

City A lies directly west of City B. When there is no wind Captain Dare A. Devil makes a round trip of 6000 km between the two in 10 hours in his airplane while traveling at same speed up and down. Once a strong steady wind was blowing from west to east, and the round trip took him 12 hours. How...

For demonstration purposes I m trying to assemble a generator consisting of a coil swinging thru a permanent magnetic field. The coil should hang from a small windflap and should be able to temporarily light up an LED. Currently I am concerning myself with the design of the windflap which...

How does a rocket get tested in a wind tunnel? what is it's orientation? an airplane is facing the air, like in reality, as it flies. so does that mean you mount a rocket vertically, but have the wind come on the side? or do you mount it pointing in the direction of the wind? and does...

A 100-meter dash is run on a track in the direction of \vec{v} = 2\vec{e_{1}}+6\vec{e_{2}} . The wind velocity \vec{e}_{1}+\vec{e_{2}} km/h. The rules say that a legal wind speed measured in teh direction of the dash must not exceed 5 km/h. Will the race results be disqualified due to an illegal...

I believe this has just been tested (again) yesterday (Sept 17th/07) From: http://www.scenta.co.uk/scenta/news.cfm?cit_id=1217038&FAArea1=widgets.content_view_1&search_text1=&startrow1=16 The electric car just got a boost from the power generated by its own wind...! Article from JCNNetwork...

A 100-meter dash is run on a track in the direction of \vec{v} = 2\vec{e_{1}}+6\vec{e_{2}}. The wind velocity \vec{w} is 5\vec{e}_{1}+\vec{e_{2}} km/h. The rules say that a legal wind speed measured in teh direction of the dash must not exceed 5 km/h. Will the race results be disqualified due to...