Wind Definition and 829 Threads

As I'm sure we all know, that when you go sailing your fastest speed isn't directly downwind but when you are traveling at an angle to it. This allows sailboats and iceboats to go several times faster than the wind speed that is powering them. But how is it that a vehicle such as...

Homework Statement An airplane is traveling at 30 m/s and wishes to travel to a point 8000 m NE (45 degrees). If there is a constant 10m/s wind blowing west: A) In what direction must the pilot aim the plane in degrees? B) How long will the trip take? Homework Equations Basic...

Hello, I am Daniel from La Plata, Argentina and would like some help on a complex (for me) question. I am working with some friends on the development of an innovative wind turbine. We have built several prototypes with diameters of 0.5 m and 2 m. We have tested these prototypes on trucks with...

Description of method: The rotor's mass is constant so when it accelerates in a given wind, it does so with an acceleration = torque/mass. This acceleration will depend essentially on wind speed. If tests are carried out in the open with non-turbulent winds it is possible by using a tachometer...

can someone explain in simple terms what does 1mw wind turbine mean? how many houses can this power? if it is a 500w turbine, how many houses can this power?

I'm about to start a project in which I want to study the effects of making modifications to a wind turbine blade. I am going to be able to use various external flow modeling software our aerospace labs. I am a mechanical engineer and am used to using solidworks and I understand that that can be...

A light plane attains an airspeed of 470 km/h. The pilot sets out for a destination 800 km due north but discovers that the plane must be headed 17.0° east of due north to fly there directly. The plane arrives in 2.00 h. What were the (a) magnitude (in km/h) and (b) direction of the wind...

We honestly haven't gone over this in class and I have no idea why my prof wants us to do this question... so I'm given it a go and come up empty. NEED HELP! Homework Statement Calculate the maximum theoretical power from a wind turbine if the radius of the vane area is 18.1 m and the wind...

Resultant wind speed/direction... Hi, new here and am hoping this is in the correct forum and if so that someone can help with this little problem. Basically I would like to know if there is a "quick" way of calculating an average or resultant wind speed and direction given a selection of 5...

To stop it from blowing out. Should you just have a 2 inch plastic around where the flame is?

A sailboat is sailing due east at 5.40 mph. The wind appears to blow from the southwest at 13.4 mph. 1. What is the true wind speed? 2.What is the true wind direction? ( south of west). 3.What is the true wind speed if the wind appears to blow from the northeast at 13.4 mph? 4.What is the...

Friends, I have a solid (not mesh) parabolic dish mounted on a 2-axis tracking mechanism. This assembly is often mounted atop buildings or open scapes and is subject to direct and indirect wind loading. I am trying to recall my fluids and aero schooling but am not sure of some assumptions...

I'm not sure if this is the right place to ask, but would any of you have recommendations as to where I can get this online first or preferably second hand at its best price? Alternatively, do any of you have this book and you wouldn't mind selling? My country is plenty small and my whole...

HI i am looking some virtual windtunnel software that there i have to desgin a various nose cone and i have to find the shock wave formation at supersonic speed please some one help me to find the virtual windtunnel and CFD software regards Ryan

Or any specific requirments formulas that will help me on my way in building one please. Moderator's note: this thread is from 2008.

my aim is to lower the cut in speed of the horizontal turbines. I know wind speed has a brutal effect on turbine output, so I want to use horns to speed up air. I plan to put a horizontal axis turbine in the midle of the hexagon You see on the pic. Each side of the hexagon is like a...

i know climate science is pretty inaccurate at the moment and its difficult to predict the effects of lowering carbon emissions but just as an interesting topic i was wondering roughly how many lives each wind turbine will save? what i mean is how much carbon dioxide will be saved from the...

I have constructed a wind tunnel with approximately 15 x 15 in. cross-sectional area test section. Where can i get some ideas/plans to build a simple force balance that can measure lift and drag forces simultaneously? Currently I'm using a single-axis button load-cell setup to measure...

This years's grants have been announced. A total of 2.7 million was awarded. FQXi is set up to support investigation of foundational questions. Here is a sampling of the awards, chosen with a hefty componenent of randomness. Gives an idea of some of the kinds of things FQXi supports.Stephon...

As part of a wind turbine design project, I have come to selecting the most appropriate coil and permanent magnet configuration. The aim is to design a turbine capable of 3kW (max), and approximately 300rpm. It will use mechanical furling to regulate speed. So far, I have only seen...

Hi All, I am trying to calculate the rotational torque created on a shaft from a rotating blade from wind pressure but have little idea how to go about this? Eg: If i have a flat piece of solid material of say 1" square or 2.54cm square facing into the wind blowing at say 30mph or 60kmh...

So I'm using a wind tunnel to show the aerodynamics of a toy truck which scaled 1:64 in the real world. My question is that if i wanted to show that it was going at 64 kilometers per hour in the real world, do i have to set the wind tunnel so that it generates 1 kilometer per hour winds? I'm not...

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...

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...