Engineering

Engineers fly first-ever plane with no moving parts

Since the first airplane took flight over 100 years ago, virtually every aircraft in the sky has flown with the help of moving parts such as propellers, turbine blades, and fans, which are powered by the combustion of fossil ...

Engineering

'Artificial leaf' successfully produces clean gas

A widely-used gas that is currently produced from fossil fuels can instead be made by an 'artificial leaf' that uses only sunlight, carbon dioxide and water, and which could eventually be used to develop a sustainable liquid ...

Energy & Green Tech

Energy tower for producing electricity set for Arizona

Solar Wind Energy Tower (SWET) with a focus on "solar wind downdraft tower" structures for producing electricity last month announced it got the green light from San Luis, Arizona, to develop such a tower in the city, which ...

Energy & Green Tech

Novel wind turbine flaps like a hummingbird

(Tech Xplore)—A Tunisian company called Tyer Wind has released details of a new type of wind turbine they have developed that is based on what the company describes as 3-D Aouinian kinematics—a wind turbine designed to ...

Energy & Green Tech

Fossil fuels blown away by wind in cost terms: study

New onshore wind and solar energy projects are set to deliver electricity more cheaply than fossil fuels plants, with other green technologies also rapidly gaining a cost advantage over dirty fuels, a report published Saturday ...

Energy & Green Tech

Wind turbine swap in Denmark turns focus on superconductors

The EcoSwing consortium announced it has taken a special generator to a site in Denmark. This was momentous. A previously installed permanent magnet generator was now swapping places with a new superconducting device. The ...

Energy & Green Tech

U.S. energy use rises to highest level ever

Americans used more energy in 2018 than in any other year, according to the most recent energy flow charts released by Lawrence Livermore National Laboratory (LLNL). Overall total energy consumption rose to 101.2 quadrillion ...

Energy & Green Tech

Danish wind power whips up record 43% of electricity

Wind power generated 43.4 percent of electricity consumed in Denmark last year, a new record for the Nordic nation which aims to rely on renewables for half of its energy needs by 2030, authorities said Thursday.

Engineering

High-speed experiments improve hypersonic flight predictions

When traveling at five times the speed of sound or faster, the tiniest bit of turbulence is more than a bump in the road, said the Sandia National Laboratories aerospace engineer who for the first time characterized the vibrational ...

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Wind

Wind is the flow of air or other gases that compose an atmosphere (including that of the planet Earth). On Earth and within other planetary atmospheres, wind consists of air molecules in motion. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space. Differences in density between two air masses lead to wind. Winds are commonly classified by their spatial scale, their speed, the types of forces that cause them, the geographic regions in which they occur, and their effect. While wind is often a standalone weather phenomenon, it can also occur as part of a storm system, most notably in a cyclone. While winds on Earth can be strong, the strongest winds within a planet in our solar system lie on Neptune and Saturn.

Winds are plotted on surface weather analyses indicating the direction the wind is blowing from as well as its strength, and over much of the globe wind speeds are measured over a ten-minute time frame, with the United States and India using different averaging intervals. Shorter duration winds, such as wind gusts, exceed the minimum value over the observed time frame and can cause substantial damage to power lines and suspension bridges. Winds with an intermediate duration, which sharply increase and last for a minute are termed squalls. Long-duration wind speeds have various names associated with their average strength, such as breeze, gale, storm, hurricane, and typhoon. Wind occurs on a range of scales, from local breezes generated by heating of land surfaces and lasting tens of minutes, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two major driving factors of large scale atmospheric circulation are the differential heating between the equator and the poles, which causes the jet stream and the associated climatological mid-latitude westerlies, polar easterlies, and the trade winds, and the rotation of the planet (Coriolis effect), which causes the circular motion of air around areas of high and low pressure. Within the tropics, thermal low circulations over terrain and high plateaus can drive monsoon circulations. In areas where winds tend to be light, the sea breeze/land breeze cycle is the most important to the prevailing wind; in areas that have variable terrain, mountain and valley breezes dominate the wind pattern.

In human civilization, wind has inspired mythology, influenced the events of history, expanded the range of transport and warfare, and provided a power source for mechanical work, electricity, and recreation. Wind has been used to steer sailing ships across vast oceans. By air, hot air balloons use the wind to take short trips. Airships have historically been used for longer trips, but nowadays are used for a variety of monitoring efforts such as during public sporting events and drug trafficking efforts. Wind can be dangerous, as areas of wind shear caused by various weather phenomena can lead to dangerous situations for airplanes. When winds become strong, trees and man-made structures are damaged or destroyed.

Winds can shape landforms, via a variety of aeolian processes such as the formation of fertile soils, such as loess, and by erosion. Dust from large deserts can be moved large distances from their source region by the prevailing winds. Winds that are accelerated by rough topography and associated with dust outbreaks have been assigned regional names in various parts of the world due to their significant effects on those regions. Wind helps to spread wildfires. Nature uses wind to help disperse seeds from various plants, in order to enable the survival of those plant species, as well as flying insect populations. When combined with cold temperatures, wind has a negative impact on livestock. Wind impacts animal food stores, as well as their hunting and defensive strategies.

This text uses material from Wikipedia, licensed under CC BY-SA