What is the Air / smoke / Fog that appears on the wings and nose of a Jet air fighter when it is turning?

Question

I've seen some Jet Fighters on the Tv making high G turns, what is that fog that appears on the wings? why does it occur?

Answer 1

It is water.  Low pressure cools the air and condenses the water from its vapor form.  

Water vapor is not visible.  

There is no sound barrier.  The speed of sound is not a barrier.

Answer 2

It's not an easy answer- I guess to say that the air gets super heated by the friction of  moisture laden air. Don't forget that steam is very easy to produce and it has an expansion factor beginning at 80 times. The fog you see is condensate; which occurs at varrying predictable rates called precipitation. Good question and good luck in your studies

Answer 3

It's water vapour. My dads an aircraft engineer. I don't know how it happens so i won't try and blag you. Hopefully someone else can help you? Good Luck

Answer 4

There are two different types of clouds formed on an upper surface of the wing.

The first is due to low pressure generated during a high rate turn or  increase of Angle of Attack.

Wings produce lift by creating an area of low pressure on the upper surface of the wing and and total lift is increased when the Aof A is increased. As pressure and temperature are proportionate to each other. (as pressure decreases, temp decreases and vice versa). So during a high g' rate of turn or climb, the total lift has to be increased by the number of G's to maintain altitude and perform the turn. This decrease of pressure is lift, but because pressure is related to temp, the decrease temp is enough to allow for adiabatic cooling of the air. (the air cools to the the dew point, or 100%humidity) allowing for the formatiation of clouds.

The second is the shockwave cloud. When an aircrafts surface exceeds the speed of sound, a shock wave will form compressing the are ahead of wave. This is what causes the sonic boom. But the wave also prevents the flow of air from passing the shock wave,  causing a vaccum behind the shock wave that will allow for the air to cool to the point of 100% Relative Humitdity allowing for the formation of a vapor cloud.

Answer 5

Condensation.  The shock wave of air is dense enough for water to form on it.  Same thing happens when a jet fighter hits the sound barrier.  National Geographic had an amazing photo of an F-14 hitting the sound barrier in 1980 (don't remember the month, but it also had an article on Mount Saint Hellens).

Answer 6

These 'fog' clouds are wingtip vortices which are like ice crystals forming into artificial cirrus clouds. Usually occur on humid days.  On the nose is basically the same thing and it's when the aircraft begins to travel faster than sound itself.  It's breaking the speed barrier.

Answer 7

water mostiure because the plane is hitting the water particles with a strong force

Answer 8

Why does condensation occur? Once the pressure of water vapour in the air exceeds the saturation vapour pressure it is no longer stable. Provided there are dust particles present to act as nucle, the excess vapour over the saturation pressure condenses into droplets. Without nuclei, condensation is difficult and instead the air becomes supersaturated.  However, when the supersaturation exceeds a certain critical value water does condense out very rapidly as a mist of fine droplets even though nuclei are absent. This is homogeneous nucleation.

The flow over the top of aircraft wings is faster than elsewhere. The fast flowing air is at a lower pressure and expands. In doing so it cools. If the air humidity is high enough and its temperature also fairly high (warm air can hold more water as vapour than cold air) then conditions might be reached for heterogeneous or even homogeneous nucleation followed by rapid droplet growth. In some cases the air might already be supersaturated before the aircraft passes. The result? We see trails of vapour from the wings and other surfaces.