Wind Definition and 861 Threads

Belts and pulleys for WIND TURBINE ? Hi, I have been working on a Vertical Axis Wind Turbine. The blades I am able to fabricate produce more torque than speed. I am adding a synchronous belt drive transmission. The current configuration is 1 rpm at the input and 7 rpm at the output. I have...

Homework Statement If wind blows at 35m/s over a house, what is the net force on the roof if its area is 240m^2 and is flat? Homework Equations P=F/A and P1 + 1/2pv^2 = constant The Attempt at a Solution I have no idea on how to find pressure, because if I sub it into P1 + 1/2pv^2 =...

Homework Statement In a tornado or hurricane, a roof may tear away from the house because of a difference in pressure between the air inside and the air outside. Suppose that air is blowing across the top of a 2200 ft2 roof at 136 mph. What is the magnitude of the force on the roof...

Please Help! In dealing with wind induced forces, caused by vortex shedding action over a circular cylinder, we must calculate the parameter "Kw" (effective correlation factor), which depends on "L/b", "L" beeing the "correlation lenght" (Eurocode). Is there any method, analytical (or...

So, I am totally not an aerodynamic engineer, but my boss - an organic chemist- thinks we should get a wind tunnel to test some new polymer coatings that our research group developed. In researching and calling around to companies that make wind tunnels, I got a question that i have no idea how...

Homework Statement If you jumped out of a plane you would begin speeding up as you fall downward. eventually due to wind resistance your velocity would become constant with time. after this occurs the magnitude of the force of wind resistance is a. slightly smaller than the force of...

Intuitively I would say no because it seems like a big call but at the same time the high energy effects rely on the interaction between magnetic fields and gas don't they? Any tips or just an idea of where I can find out would be awesome

Homework Statement 1. Homework Statement A 373-kg boat is sailing 13.0 ° north of east at a speed of 2.00 m/s. 32.0 s later, it is sailing 33.0 ° north of east at a speed of 3.90 m/s. During this time, three forces act on the boat: a 33.1-N force directed 13.0 ° north of east (due to an...

Homework Statement An airplane is heading due south at a speed of 500 km/h. If a wind begins blowing from the southwest at a speed of 100 km/h, calculate the velocity of the plane relative to the ground, and how far off course it will be after 10 min. if the pilot takes no corrective action...

use of wind powered turbine in cars ?? helloo.. I'm just thinking to build an wind turbine powered car using with electric motor like an hybrid car .. there are certain question arises in my mind are .. that the use of turbine as a source of energy will be efficient or just theoritical concept...

i am making a wind tunnel in order to test aerodynamics of 1/24 scale cars. i am having two problem: 1. i am not sure what wind speed at that scale to represent 100mph. 2. i am using a fan that has an outlet wind speed of 19.4 mph. i tried to increase wind speed by decreasing the outlet...

I'm doing a project regarding a canyon in the Big Bend National Park area. I'm supposed to be building an outpost on the edge of a canyon for rangers overlooking the area, and I'm needing to make it sustainable, meaning that it would utilize natural resources to make the house function...

Hi all, I'm studying for my and I've been trying to do one of the past exams from the University of Auckland. Unfortunately I'm not so clever so I'm asking for some help Two design proposals for a wind park have been made. The first design uses 10 turbines, each with a height of 90m and a...

I'm building a yaw control system for one of the universitys VAWT turbines. I need to design a slewing bearing which can reliably support radial, axial and tilting moments. I have absolutely no idea how to do this or even where to start. Could you please give me some advice as to go about...

Homework Statement How should the thrower adjust the angles of launch if he is throwing the object into a velocity of 40 m/s wind? Homework Equations N/A The Attempt at a Solution I really have no idea. Personally, I think throwing the object at a lower angle would help throwing...

I was reading an earlier post about having a wind turbine embedded in a vehicle to generate electricity as it moved. I came to this site after having this thought last night. But I realized immediately that drag and weight would be counterproductive. However, I did ponder an alternative...

Does anyone know of any simple aerodynamics simulators? Preferably one that would allow me to import a 3D model and then calculate its drag coefficient? I have done a few searches, but failed to find much of anything. Oh, and it needs to be free. Not part of some mutli-hundred dollar...

Hello Friends. I have a question that may have to do with wind lift and other effects. I have two wooden poles set into the ground. Both poles are upright and has a height of H feet. The horizontal separation of these poles is S feet. Let's say I attach a rope in between these poles so that...

Hello Friends. I have a question for the following scenario: There are two wooden poles, both set into the ground so that they are sticking straight up. The height of Pole One is H1 feet. The height of the Pole 2 is H2 feet. Supported in between these two poles is a wire. The ends of the...

What does happen to the wind after it passes through a wind turbine blade? Does it increases the wind speed?

This thread is for MATH regarding wind powered vehicles. I don't want to see your opinion. I want facts and math. PERIOD This is my (attempted) derivation of what a wind powered car is capable of. I may have accidentally derived an infinite energy machine, so if someone would check my work...

Hi everyone! I am new in physics forum and this is my first post. I need help from the people out there. I wanted to deisgn a Vertical Axis wind turbine to produce 5k Watt output with a frequecy of 50Hz, 220VAC, to completely run my home appliance 24 hours. Appliances include: -1.5ton...

One of the all-time great science mysteries is now a step closer to explanation. The surface of the sun, known as the photosphere, can reach temperatures of 5,000 degrees. To many it would seem logical that the temperature would lower further away from the sun. But, the outer atmosphere, known...

Homework Statement An airplane has an airspeed of 145 km/h. it is to make a flight in a direction of 72 degees while there is a 32-km/h wind from 342 degrees. what will the airplane's actual heading be? Homework Equations trig functions The Attempt at a Solution this is a calc3...

I'm trying to model a vertical axis wind turbine with the double-multiple streamtube model (with Matlab), where wind speed is dampened by an induction factor so that the output is different for upwind and downwind parts of rotation. The trouble is that for the downwind part, the induction...

At the current rate of oil consumption, the world will run out of it in twenty years. The Netherlands is investing somewhat into wind energy since that's one of the few renewable resources around in our country. Now the obvious problem with wind energy is that it is unreliable, so people are...

hey! Wind turbines have got certain threshold speed of wind (of about 6-7 m/s) which acts as a mechanical resistance to its rotation. Is this mechanical resistance a result of frictional resistance in bearings alone, or it is also a result of its own weight? If yes, approximately how much...

I recently read this http://www.earthtechling.com/2011/06/wind-turbines-board-europe-ferries/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Earthtechling+%28EarthTechling%29&utm_content=Google+Reader" and it's really bugging me. They claim that by putting wind turbines on the...

Hello! I am new and recently figured out how to make wind tunnels in 3ds max and Maya. Im helping to develop a sci-fi game and just out of curiosity took one of our spaceship models meant for space to planet travel into the wind tunnel to see if it would really be able fly, and if not, find out...

http://www.sauerenergy.com/index.php?option=com_content&view=article&id=50 The link above gives a picture and rough model of a Sauer Wind Turbine. I was wondering, since the dimples on the turbine were based on the idea that a golf ball reduced air resistances, how it would help the wind...

Hello Everyone, I have a fairly simple wind tunnel question but I cannot seem to connect the pieces. Homework Statement Consider a low speed one-circuit wind tunnel with an inlet to throat ratio of 12. The pressure difference between the inlet and the test section was measured to be 10...

To calculate the force of wind I use the following simple method: Speed in mph^2 x .0027 = psf. Anyone know of a simple method of calculating psf using the speed of water? Please.

Greetings, for the school I must find some information about the building of a small close wind tunnel . Some one know where to find it? Good day!

Homework Statement A wind turbine is initially spinning at a constant angular speed. As the wind's strength gradually increases, the turbine experiences a constant angular acceleration 0.127 rad/s2. After making 2790 revolutions, its angular speed is 155 rad/s. (a) What is the initial angular...

Homework Statement A sailboat is traveling east at 5.0 m/s. A sudden gust of wind gives the boat an acceleration a =(0.80 m/s^2 and 40 degrees north of east). Homework Equations V = Vo + at X - Xo = Vo*t + .5at^2 V^2 = Vo^2 + 2a(X - Xo) The Attempt at a Solution I...

Homework Statement Air of density 1.2kgm-3, speed 8ms-1 is incident on blades of wind turbine. Radius of blades 1.5m. After passing blades, wind speed is reduced to 3.0ms-1 and density 1.8kgm-3. How much power is extracted from wind?Homework Equations P=1/2 pAv3The Attempt at a Solution P=1/2 x...

Can wind disrupt TV reception in any way other than the two most obvious ways: 1) blowing the receiving antenna out of alignment, and 2) blowing obstacles like trees into the path of the signal? I would think the actual air currents would be invisible to the radio waves...am I wrong?

Hello all, I am not an engineer, but I am a 32 year steel fabricator, I have recently built a 17 foot wind turbine with an axial flux alternator, I would like to build a tower for it but would like to get a general idea before I go to a local engineer for actual stamped drawings which are...

Hello. The title of this post may seem too hardcore. Actually, I am building a simple wind turbine made from wood and aluminium thin plate. it has three blades and 120 cm in diameter. It should be at least 3.5 m above ground, on a steel/wood column. I have no idea how to install this pole...

I am making a wind tunnel to test the lift of an airfoil when chaning the variables of angle of attack and air velocity. For a good EEI I need more then 3 speeds. However, all the people I know only have 3 speed fans, I don't know how to get more speeds as the wind tunnel gets built around the...

Homework Statement I am trying to determine the input I will have on a shaft with a continuous force of 3,720 pounds one foot out from the shaft center. I am thinking the input continuous torque would be 1 foot being that I am using a 2 foot pulley on the shaft, and I have a continuous...

I want to know that how is govering is executed in case of wind mill to ensure that generator's shaft rotates at constant speed so as to generate electricity at fixed frequncy. Like in case of hydroturbine, governing is done by regulating water flowrate.

My Semester Project Is "Dynamic Analysis of Wind Turbine Blades" In ANSYS 9 Environment ... I've Modeled Wind Turbine 'Rotor Assembly' In Pro|Engineer And Successfully Imported Into ANSYS ... I've Practiced 'Static Analysis' Only In The ANSYS Environment ... So It Leaves Me With A ZERO-LEVEL...

This curiosity began with my attempt to find a general simplified formula for wind force displaced perpendicular to a surface with relation to the velocity of wind and the area of the surface {analogous to the simple models in UP 1 for describing motion}. This curiosity had its orgins with...

I just read up on this and I am wondering if this person could be correct. He believes that winds are created by convection currents created by the heating and cooling of air. The air over a warmer ocean coming in contact with cooler air over land or vise versa. Now he says that these effects...

I have done a lab experiment, to determine the coefficient of lift for an aerofoil, keeping the angle of attack constant. The equation I have used is Lift= (1/2) v times v times A times ρ times Coefficient of lLift v= Velocity of air ρ=air density A= planform area to give...

Hi everyone. This is my first time trying this. So please be gentle. My question is to do with a dc motor. I want to build a wind generator and I am trying to figure out what size motor to start with and try to size the blades to get the best out of it. I know that their is a lot of other...

Imagine that i have a source of _constant_ wind. It travels, with negligible variance, at 50 mph. The problem is that at the accessible point, the source of the wind has an opening of only 1 meter across. (Basically, at this point, imagine a small wind tunnel). The question is, how much...

Hi I wasn't sure whether this is technically homework or not but anyway. I am building a miniature wind turbine for a basic project just for myself. I was wondering if there was anyway for working out the voltage gained from the generator. I know this could be gained from using P = IV but...

Homework Statement My son and I have built a wind turbine following the plans on: Build your own Wind Turbine Designed by Dave Mussell http://www.re-energy.ca/docs/wind-turbine-cp.pdf" . These plans were inspired by the Picoturbine: link to manufacturer and link to PDF. We used 30 AWG...