Tag: airplanes

First Ever Plane With No Moving Parts Takes Flight

The first ever “solid state” plane, with no moving parts in its propulsion system, has successfully flown for a distance of 60 metres, proving that heavier-than-air flight is possible without jets or propellers.

The flight represents a breakthrough in “ionic wind” technology, which uses a powerful electric field to generate charged nitrogen ions, which are then expelled from the back of the aircraft, generating thrust.

Steven Barrett, an aeronautics professor at MIT and the lead author of the study published in the journal Nature, said the inspiration for the project came straight from the science fiction of his childhood.

I was a big fan of Star Trek, and at that point I thought that the future looked like it should be planes that fly silently, with no moving parts – and maybe have a blue glow.

But certainly no propellers or turbines or anything like that. So I started looking into what physics might make flight with no moving parts possible, and came across a concept known as the ionic wind, with was first investigated in the 1920s.

“This didn’t make much progress in that time. It was looked at again in the 1950s, and researchers concluded that it couldn’t work for aeroplanes.

“But I started looking into this and went through a period of about five years, working with a series of graduate students to improve fundamental understanding of how you could reduce ionic winds efficiently, and how that could be optimised.”

How the world’s first solid-state aircraft used ‘ionic wind’ to fly

In the prototype plane, wires at the leading edge of the wing have 600 watts of electrical power pumped through them at 40,000 volts.

This is enough to induce “electron cascades”, ultimately charging air molecules near the wire.

Those charged molecules then flow along the electrical field towards a second wire at the back of the wing, bumping into neutral air molecules on the way, and imparting energy to them.

A time lapse image of the craft in flight in an MIT gym.

Those neutral air molecules then stream out of the back of the plane, providing thrust.

The end result is a propulsion system that is entirely electrically powered, almost silent, and with a thrust-to-power ratio comparable to that achieved by conventional systems such as jet engines.

The successful flight of the plane – which has no name beyond the uninspiring “Version Two” – owes as much to the engineering prowess required to make it as thin and light as possible as it does to the propulsion method itself.

The plane weighs just 2.45kg, but manages to fit in a five-metre wingspan, battery stack, and a high-voltage power converter.

In the longer term, the ability to power flight purely through electricity opens up the possibility of carbon-neutral flight, which could lower the emissions of the aviation industry globally.

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Pass it on: Popular Science

How Do Planes Fly? Thrust and Drag

Drop a stone into the ocean and it will sink into the deep. Chuck a stone off the side of a mountain and it will plummet as well.

Sure, steel ships can float and even very heavy airplanes can fly, but to achieve flight, you have to exploit the four basic aerodynamic forces: lift, weight, thrust and drag.

You can think of them as four arms holding the plane in the air, each pushing from a different direction.

First, let’s examine thrust and drag. Thrust, whether caused by a propeller or a jet engine, is the aerodynamic force that pushes or pulls the airplane forward through space.

The opposing aerodynamic force is drag, or the friction that resists the motion of an object moving through a fluid.

If you stick your hand out of a car window while moving, you’ll experience a very simple demonstration of drag at work.

The amount of drag that your hand creates depends on a few factors, such as the size of your hand, the speed of the car and the density of the air.

If you were to slow down, you would notice that the drag on your hand would decrease.

For flight to take place, thrust must be equal to or greater than the drag. If, for any reason, the amount of drag becomes larger than the amount of thrust, the plane will slow down.

If the thrust is increased so that it’s greater than the drag, the plane will speed up. Every object on Earth has weight, a product of both gravity and mass.

A Boeing 747-8 passenger airliner, for instance, has a maximum takeoff weight of 487.5 tons (442 metric tons), the force with which the weighty plane is drawn toward the Earth.

Weight’s opposing force is lift, which holds an airplane in the air. This feat is accomplished through the use of a wing, also known as an airfoil.

Like drag, lift can exist only in the presence of a moving fluid. It doesn’t matter if the object is stationary and the fluid is moving (as with a kite on a windy day), or if the fluid is still and the object is moving through it.

What really matters is the relative difference in speeds between the object and the fluid.

As for the actual mechanics of lift, the force occurs when a moving fluid is deflected by a solid object. The wing splits the airflow in two directions: up and over the wing and down along the underside of the wing.

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Pass it on: Popular Science