What are the advantages of a variable sweep wing over a fixed-wing aircraft?

The needs of the aircraft are different, in order to increase the flight speed, it is necessary to choose a wing with a large sweep angle and a small aspect ratio to reduce the shock drag of the aircraft, but this type of wing has less lift in the subsonic state, the induced drag is larger, and the efficiency is not high.

Ordinary aircraft, can only choose the wing sweep angle at a certain angle, is a compromise scheme, taking into account the performance of high speed and low speed, but everything can only be sparse.

From an aerodynamic point of view, in order to meet the requirements of the aircraft for supersonic flight, subsonic cruise and short-moment take-off and landing at the same time, it is best to make the wing sweep and use different sweep angles to adapt to different flight conditions.

This is the basic design idea of the variable sweep wing, which allows the wing to rotate back and forth to change the sweep angle size, so that the aircraft can take into account the aerodynamic requirements of both high-speed and low-speed flight, and expand the flight speed range.

Specifically, when the aircraft takes off, lands or needs to fly at low speed, the wings are rotated forward to reduce the sweep angle, so as to improve the low-speed flight performance of the aircraft and shorten the take-off and landing running distance; When the aircraft needs to fly at high speed, the wing is rotated back to increase the sweep angle to reduce the flight resistance and improve the high-speed flight performance of the aircraft.

Therefore, variable swept wing technology can solve the contradiction between high and low speed of supersonic aircraft and improve take-off and landing performance.

Now, all sorts of dazzling maneuvers, with the wings extended, hovering faster and making turns that are almost comparable to those of previous propeller planes.

Then, the wings suddenly turned to the back, as if the eagle suddenly preded, and when it swooped down, the eagle would retract its wings, and it was so flamboyant that it began to make a high-speed move, which immediately made everyone applaud.

(Readers can probably imagine in their minds that both wings turn to the back at the same time and finish sweeping, this action can be said to be the most handsome, and it is also the most classic scene in the hearts of every Tomcat fan.) ）

High-speed through!

The huge Tomcat fighter, like a flying lock mark, flew from one side of the runway, brushing the ground to the other side, because the wing sweep, so that its body looks more coordinated, the wing is almost parallel to the horizontal tail, in this case the high-speed performance is quite powerful.

Moore closed his eyes, he didn't want to look any more.

He knew that this time he was going to lose.

Although he knew about cheating, he could no longer say it, and Kissinger's meaning just now was obvious: no matter which one is sold, it will be beneficial to the US government, and in the case that Congress does not allocate funds, foreign arms sales are the best way. Mutual demolition will not be allowed.

The other party must have gotten rid of the oil, but I don't know what the method is, I have been paying attention to it, and I didn't find that the other party used a pumping truck, and now, it's too late to say anything, this business is cheap for the navy!

Just as he closed his eyes, he missed an even more exciting shot.

If you only do the prescribed actions, of course, you can't fully show the heroic posture of the Tomcat fighter, and Nathan's smooth movements are not yet over.

Low-speed through-field.

For jet fighters, high-speed flight is the first consideration, and when high-speed flight is taken care of, the low-speed capability is insufficient, that is, when the speed is low to a certain extent, the aircraft will directly stall and crash because the speed is too low.

The smaller this minimum speed, the more powerful the aircraft's low-speed capabilities are, and it will come into play against some low-speed aircraft, such as helicopters or propeller aircraft.

The wing sweep angle of the Tomcat fighter is computer-controlled, and the appropriate sweep angle is selected according to the speed, but manual can also be intervened.

At this time, the Tomcat fighter is only one meter above the ground, in the air above the airport runway for a low-speed clearance, just now when the F-15 fighter is doing, it is still 3 meters high.

At this time, the aircraft's altimeter completely loses its effect, and it all depends on the pilot's own feelings to fly, and the slightest carelessness will have serious consequences.

Nathan was sure.

As the plane flew in the middle, directly in front of the distant stands, Nathan suddenly turned on the afterburner and began to climb rapidly, and just as he took the lever into his arms, he pushed the rudder on the left side to the ground.

If he hadn't fixed the wings, he would have begun to turn backwards at this time, and now, the wings were still in a state of expansion, and in this amazingly compact sharp turn climb, the surface of the wings suddenly rose up in patches of white mist.

This white fog quickly evaporated from the wings and from the rear fuselage, surrounding the entire rear fuselage, as if entering a fairyland, as the plane climbed, this white fog also followed the plane to rise, forming a beautiful scene.

"Wow!" The scene immediately let out a sigh of surprise, this picture is simply too beautiful, even in Top Gun, there is no such shot, only the shape of the shock cloud of the plane breaking through the sound barrier.

When the plane breaks the sound barrier, a cone-shaped cloud appears, and the nose passes through the head of the cone, which is shrouded in the center of the fuselage, which looks quite beautiful.

And now, unlike that sharp cone, these white fogs are pulled out by the fuselage itself, which looks even more exaggerated and has a more sensational visual effect.

At this time, Brown had already gotten off the F-15 fighter, he stood at one end of the runway, looking at this magnificent scene, from his point of view, the sunset was behind the fuselage of the plane, the whole fuselage was in the clouds, extremely chic, this action, it was really shocking.

I didn't think that I could do this! He was already jealous in his heart.

The principle is not difficult.

This can also be called a shock wave cloud, but it does not cross the sound barrier to appear, as long as the air humidity reaches a certain condition, the shock wave generated by the high-speed relative motion of the air when the aircraft reaches a certain flight speed can precipitate such a foggy cloud.

Specifically, when the wing is making this sharp turn and ascending, a large area of low pressure appears on the wing, and according to the ideal gas equation of state, when the pressure decreases, the temperature will also decrease.

The Mirama base is close to the sea, and the air humidity is high, and when the temperature drops, the water vapor in the air will condense, forming a beautiful large white fog in the low-pressure area of the wings!

This action was quite shocking, giving everyone present a very strong intuitive impression, playing a clever Nathan, of course, has not finished the performance, and there are still good looks behind.