Wind Definition and 861 Threads

Summary:: how we can de ice the turbine in case of sudden frezzing like what happened in texas hello all : i was watching the news and saw the news talking about frezzing of wind farms in texas state , and losing about 35% of the energy due to that problem can we use the following methods to...

On a previous thread (now locked) I was wondering about how, precisely, the Earth's magnetic field protects us from the solar wind. Posting this here because what I wrote in that thread is very wrong, and I think it's an interesting topic. I had a hell of a time finding good information. I...

According to wiki sources "The average mass ejected is 1.6×1012 kg" I would like to know, what part of that falls to surface of the Earth?

I have to estimate the Reynolds number of the fluid flowing around a blade but I only have one detail: the length of the blade is 0.66m. I have no idea how to do it and I got to submit the assignment in a week, I am desperate for help here.

Hi everyone. My high-school student got the following homework exercise at school which I have problem with: Smoke from the steam locomotive is carried by horizontally blowing wind. Shape of the smoke trail is shown in the attached figure. Using the drawing, determine velocity of the wind...

Earlier today I realized that, when a strong gust of wind would blow through my area, it would pick up leaves off the ground and typically blow them in circular patterns, and typically the leaves would go in at least several complete circles before coming to rest back down on the ground. Why is...

Why when I move my hand faster to long distance and apply force I get more air but when I move my hand fast to shorter distance I barely get any air

Does wall to wall airfoil produce downwash in wind tunnel ?

How to determine rpm of rotational body such as wind turbine blades. Is there any relation of input wind velocity with the blade rpm? If the rpm formula in relation to input wind velocity is known then I can choose exact matching rpm for electrical generator for a given power output. As per...

Could I please ask for any help with the following question: Here's my attempt: (i and j are unit vectors in the directions of east and north respectively) (apologies that LaTeX is simply not working for me, I'll label the angles in each case T and P as shown in my diagram) Let the...

Please can I ask for help with the following as to where I'm going wrong. Book answer is 20 knots and 315 degrees My solution: In the below diagram I have sketched the two situations, k is the true speed of the wind. First question is, is my diagram correct? The velocity of the wind...

Greetings, how do - the velocity distribution of the solar wind at 1 AU - the velocity distribution of the solar wind in our line of sight look like? I have found the 400 Km/sec but no further information. Is it an average values? Is this radially on the sun the same? Links with graphs are...

Here it is given that the flag flutters in the direction of wind w.r.t. to man. But why would the direction of fluttering of flag would change without any tangential acceleration. Is there a pseudo force acting on it. I think the direction if fluttering should remain same.

I created this thread for a separate discussion of apparent wind theory from the thread about sailboats providing their own wind, which is a bit mis-leading title, since the OP's question is about using a fan blowing against a sail to move the sailboat forwards. A quote of a post from that prior...

Could someone please help me see where I am going wrong here? During a race between two boats A and B there is a wind of 18 km/h blowing from due north. The resultant velocity if A is 12 km/h on a bearing of 060. Find the direction of the wind relative to A. My reasoning: (Relative to the...

Dear experts, I'm looking for some approximate (but reliable) design loads and geometry for wind turbine towers to perform a comparative FEA study. I don't need very exact data. I just want some load levels for different wind towers, e.g. for 5 or 10 MW on- and off-shore wind turbines, and...

Hello everyone. Sorry for the mistakes on my English on this post and on the H/W statements (it is translated by me). I have a homework problem on Meterology Physics, about a ship's Apparent Wind , and it is about the a) question and maybe i don't know well the theory to solve this problem. (I...

Summary:: How is the pitch axis location of an aerodynamic profile decided? Hi, I drew a wind turbine blade in a CAD software. I used information on the pitch axis location I had on the various aerodynamic profiles I used to draw the blade. I understand that it allowed me to align the various...

I know that I'm supposed to use Weibull, but why does my teacher take the middle value, 5 m/s? Should one not integrate the formula and the use 4,5 and 5,5 as limits? This is what he has done: He then writes: makes a guess of an interval of 1 m/s and get: To be honest, I really don't...

I happened to be watching this cartoon and this one scene seriously bothered me... This... just feels like it wouldn't be a workable solution. Am I wrong? I can't say I perfectly understand how fans or propellers work, but I would imagine that by pushing air or water in one direction, equal...

I was wondering do strong wind slow down or has any effect on the outcome of your free fall? Like slower down your impact or help you survive? Hypothetical, you free fall down height of 1,000 feet below are just rocks so hard surface (not water). Basically it should cause death. But let say...

Homework Statement: Mike the Mailman takes his oath seriously: "Neither snow, nor rain, nor heat, nor gloom of night stays these courageous couriers from the swift completion of their appointed rounds". Even though a blizzard is raging outside, he goes out to deliver the mail. He makes four...

Honestly I have no idea how to solve this. Can anyone help?

For a project I need some dry workspace outdoors, so I build a wooden frame and covered it by a tarp. It's kind of like a carport with a A-roof where one side is 2,4m, the other is 3,6m. Angle of inclination is 30 degrees on both sides. Length of the building is 10m. The roof frame is placed on...

The very idea is, to use wind turbines as guardian lines to slow Wildfires. 1. Power of Wind gets reduced (for needful direction) by such guardian lines. 2. Wildfire provides additional electricity. 3. those towers can be geared to spray retardants. 4. prescribed burns becomes more efficient &...

Hello, This is an enquiry about the wind turbine electricity and battery storage. I am framing it based on my limited understanding. Please advise me. I intend to install and capture the wind energy through a small wind turbine at my home. The turbine shaft will be directly connected to the...

How can I calculate the braking torque in wind turbine?

Hello. For a long time, I wanted to build a wind turbine prototype that would have two concentric rotors. The design was inspired by an automotive torque converter, used with automatic transmissions. This device would have an external rotor that would be coupled to one generator and an internal...

During hurricane Lenny in 1999, I was anchored on my sailboat in a protected cove in the Virgin Islands. The winds were about 60 mph with gusts to an estimated 80 mph where we were. I observed that during the gusts, the salt water would "boil", that is, totally evaporate the surface into a cloud...

Problem Statement: The Doppler effect is routinely used to measure the speed of winds in storm systems. As the manager of a weather monitoring sta- tion in the Midwest, you are using a Doppler radar system that has a frequency of 625 MHz to bounce a radar pulse off of the raindrops in a...

Since solar and wind power are fluctuating energy sources not all of it goes into the grid when the consumer power demand is lower than that actually produced. This is a well-known drawback of solar and wind energy that everyone talks about. What I never found is an assessment of how much of the...

News: The cost of offshore wind plant has been falling rapidly and now some projects in Holland are viable without subsidy... https://www.offshorewind.biz/2019/03/13/dutch-powerhouses-reveal-zero-subsidy-offshore-wind-play/

Hope I am in the right subforum. I want to know how much a cantilevered sheet of OSB sheathing will deflect under wind load. I found the Moment of Inertia for OSB, but the units are in^4/ft. The bending equations I found use Moment of Inertia in units of in^4. The wind load will be uniform in...

<< Mentor Note -- Two threads on the same question merged into one thread >> How does the maximum Power equation change if there's an angle to the way the wind falls into the wind turbine's blades? Example, when it falls vertically to the blades, it's Pmax= 8/27Sρu13 But if there's for...

Hey guys, I'm not sure this is necessarily a physics question, so if it's not I'd appreciate it if someone could point me in the right direction; but here goes. I've been giving some thought to building a wind tunnel lately, I realize this won't be cheap on any large scale, but I just want to...

Homework Statement A cyclist traveling east at 8 km/hr finds that the wind appears to blow directly from the north. On doubling his speed it appears to blow from the north-east.. Find the actual velocity of the wind.[/B]Homework Equations Wind(relative) = Wind(Actual) - Velocity(cyclist)...

Hi everyone, I will be conducting wind tunnel tests of a NACA 0012 airfoil to obtain values of lift and drag in a low-speed wind tunnel (approx M = 0.1). I am looking for a really simple way of measuring these forces. Does anyone know of ways to achieve this? I am aware of force balance...

How do they measure wind chill factor?

1/2" kevlar rope has a breaking strength of 31,000 lbs and weighs 7.8 lbs/100 ft. = 116 kg/km So a a bit over metric ton gets you up to 10 km altitude. 2 metric tons at a 30 degree angle. Still gives you 25,000 pounds potential drag without breaking the rope. Working strength is...

Hi all, I have recently been asked to calculate the Buckling load on a beam (channel) carrying pipes, (Eulers critical load) this was no problem. Then i was asked to allow for wind loading.. I can not for the life of me figure out how to do this? Any tips for me? Thanks in advance

I want to make a dc generator and not sure my design will work. I will wind the coil on a donut shape disk and put 6 rectangular magnets on a disk rotor with North Pole face the coil. Please see attached pictures. Will this design works or have problems? Can I have one continuous coil or I...

Homework Statement A girl is riding a bicycle at 15 miles per hour due north. A steady wind is blowing at 15 miles per hour from the east. A flag mounted on the bicycle will be stretched out toward the (A) west (B) south (C) southwest (D) southeast (E) northeast Homework Equations Vector...

Homework Statement Plane is 300miles E of chicago and it leaves flying east at 500mph. Wind is blowing 50mph south. What is planes ground speed? Where is plane 0.6 hours later when pilot expects to land in cleveland? Homework EquationsThe Attempt at a Solution This is how I set it up I want...

Homework Statement [/B] So here is my question: I asked you about a solution approach/solution for the following task: Two rail paths cross at an angle of 145 °. With a constant speed of 60 km/h, they just drive along their tracks, and each of them repels steam/smoke flags, which, among other...

Dear experts, How should I compute the wind loads for a Shukhow tower, i.e. a circular cross-section steel lattice structure? The structural members should be rectangular or circular. I´ve been checking EUROCODEs EN 1991-1-4 (2005) and EN 1993-3-1 (2006) without success. Is there any other...

Hello guys, I am trying to calculate the lift force and drag force in a wind tunnel at my school as a part of a project that i am doing. I am varying the length of the airfoils and trying to measure the lift force and drag force. I have 3-d printed 7 airfoils. However, I am not able to find any...

Conventional Wind turbines now have 3 blades. I assume this is a matter of average air pressure. 1)Would a future wind turbine working on Mars with about 1% of Earth’s air pressure need to have many more blades? 2) Would all those Victorian windmills have been any more efficient with 3 sails...

Ive done some wind tunnel experiments for a wing design i made, the wind tunnel was set to 50% power and the incidence angle was increased from -2 to 14 at 2 deg increments, how do i calculate the velocity for each recording? I've done this before but I am just having a mental block on...

I've always been amazed by this, and as someone with a mechanical engineering degree, always a bit embarrassed that I don't understand this.

For my senior design project we are designing a vertical axis wind turbine (VAWT) and trying to increase efficiency by adding flexible parts to the blades. We are currently in the process of ordering a motor/generator where we can test our new model against the same model but with standard...