A large number of various magazines that select and analyze information regarding the achievements and problems of aviation often focus readers on the material aspects of the operation and structure of modernized devices, such as airplanes, rockets, helicopters and other aircraft. Often, all phenomena that occur with the internal and external structure of the vehicle during the flight are also analyzed. Usually the inverse trace reflects this. Many people watch beautiful planes that leave an even lane in flight.
The concept of this phenomenon
An inversion trail forms at the tropopause. Its appearance is influenced by water vapor, which are subjected to increased condensation. They are present in the combustion products, since hydrocarbon fuel is consumed evenly during combustion. After going outside and sufficient cooling, a bright inversion trail from an airplane or other aircraft in the air becomes noticeable.
There are special air shows that are advisable only in sunny weather. These events are organized at aerodromes with the status of the largest in the world. At this time, a large number of spectators enthusiastically watch the movement of many planes performing interesting maneuvers in the air. The main distinguishing feature of such events is to leave a bright trail from each vehicle. Often, each aircraft is distinguished by its own loop color, which helps to get the most vivid and memorable effect.
Unlike airplanes, missiles constantly leave behind themselves massive, even often formidable tracks that look not only large-scale, but also have a rich color. They are issued from aircraft with a combat mission. This procedure can be observed not only when going to special events, but also being on the street or turning on the TV on the channel of interest. So you can see the inverse trace.
Wing end vortex
It should be remembered that the aircraft in flight leaves behind a limited and fairly wide area of the atmosphere, which becomes perturbed, its composition changes for a long time. This phenomenon is often referred to as a confused wake. Usually it appears under the influence of jet engines, since during operation they constantly interact with the environment. Also, terminal vortices of the wings of the aircraft take part in this process.
If we compare the significantly negative impact on the environment, then primacy is always given to the terminal vortices of the wings. There are many symbols for tangled tracks, but most often they are drawn on special schemes in the form of a sheet with unusual edges, the ends of which are completely twisted, that is, you can compare them with vortices.
The Twisting Process: Scientific Reasoning
The twisting process can be easily explained scientifically. A bright pressure difference appears between both sides of the wings of the aircraft, that is, on their upper and lower surfaces. Air is gradually redistributed from the lower surface, since the highest pressure is observed on it, to the upper, in order to remain in the area with the lowest pressure.
This redistribution occurs through the end of each wing, due to which powerful and very noticeable eddies are formed. The force of the differential pressure matters, since the lifting force depends on it . This value has a strong effect on the wing. The stronger this effect, the more powerful and relief vortices form.
Different brands of aircraft with wing end vortex
The speed of the air flow sometimes varies, but it can be roughly determined that if the diameter of the vortex wake is about 8-15 m, we should talk about the value of 150 km / h. The end vortex can be formed in various ways. This process depends on the brand, the configuration of the aircraft. Powerful Mirage 2000 and F-16C fighters deserve attention if they switch to a position when flying with a high angle of attack.
The process of the appearance of the end vortex
The end vortex is visualized thanks to a special tracer-generator responsible for the proper presentation of the smoky trail. The action of this element is due to a change in the state of the atmosphere, which lasts for a rather long time. Then the peripheral speed of movement gradually subsides, that is, the visual object is lost and disappears.
Under the influence of time, the peripheral velocity of the vortex damps, which is why the visual picture changes shape until it completely dissolves. The tangible vortex intensity can last up to about two minutes after the plane has flown a specific place. Such a vortex has the ability to significantly affect the flight mode of the aircraft, which fell into the atmosphere, disturbed by the action of the engine of the previous vehicle.
Long termination of the end vortex
When the vortices interact with each other, they slowly sink and diverge, that is, a noticeable change in the atmosphere disappears. The inversion trail of an aircraft is an excellent object in order to observe its transformations. After about 30 - 40 seconds, he begins to change shape, since it is intensely affected by a vortex, which gradually develops. When both the inversion and vortex layers intersect, bizarre forms are created that can be calculated in advance, since various laws affect the process of their formation.
The number of lanes and the height of the inversion track are controlled by the number and location of engines in the system. At the same time, the inversion trace not only soars in the air, but also constantly changes, creating interesting contours. Most often, twisting of this layer under the influence of the end vortex is observed. All layer transformations reflect a variety of aerodynamic processes that are always formed during flight.
Separate vortex flows
Sometimes pilots are forced to carry out various attacks, which are carried out with a large angle of inclination of more than 20 degrees. In this case, the nature of the flow around the contours of the aircraft for a while varies significantly. Detachable areas begin to appear, which are mainly fixed near the upper surface of the wing and fuselage. The pressure in them greatly decreases, so immediately begins the concentration and increase in atmospheric moisture. Due to this aspect, it is possible to observe the completion of an aircraft flight without the use of tracers.
Conditions for the appearance of the vortex effect
If the angle of attack is too large, a significant halo from the cloud forms around the aircraft. When the plane flies, this cloud automatically goes into a vortex inversion trail from the plane. Typically, near the wings, bombardment regions form separation regions, due to which the appearance of a vortex rope is clearly observed. This is how the inversion trace looks, the photos of which are always fascinating.
Hot traces of rockets
Sometimes, when launching rockets, one has to deal with such cases when a stall flow is observed in the gas-air duct located in the rocket propulsion system. The gas jet emanating from the rocket engine has a high temperature, so it sometimes gets into the air intake of the carrier aircraft, which happens when the device is set to some modes.
The air flow becomes too uneven in temperature, as it is exposed to gases of elevated temperature, due to which the air entering the engine becomes changed. Motor surging is formed, that is, a stall flow occurs in the system. To identify this process, observe the main combustion chambers, since the air flow is subjected to longitudinal vibrations, passing along the engine path, and then marked by the emission of flame from these elements. So there is an inverse trace from the rocket.
Features of the inversion trace during testing
Often missile launches are carried out in the concept of testing. An exception is the on-board equipment, which serves for the purpose of recording and storing information. Often, an airplane photographer is produced with the carrier, while the process of filming is carried out, which allows you to capture the entire phenomenon on the camera. Often you can find such an inversion trace from the Buk missile.
Often, missile launches are carried out at relatively low speeds in order to better capture the entire process. At the same time, surge of the engine is often formed, since hot gases stream into the rocket engine, which destroys its air intake. An outburst of flame is immediately noted, which is characteristic when surge occurs. This is how the FSX inversion trace is expressed.
Due to this incident, the engine stops. These features after the study helped to create a number of different systems whose tasks include timely diagnosis of surging, taking measures to eliminate it, as well as transferring the engine to the optimal mode of operation with constant maintenance of its optimal state. Missile weapons in this case expands the scope of application, while at each engine operating mode, these aircraft are able to show the most stable state.
Ball of fire in the air
The MiG-29 aircraft was tested, which consisted in refueling. During one of the flights, the release of fuel fluid into the atmosphere was recorded, which was preceded by depressurization of the fuel pipeline. With the help of an airplane photographer, this unusual situation was recorded. At the same time, a certain part of the fuel fell into the engine, which almost instantly led to its stop due to surging.
In addition to the emission of flame, which always happens when the engine is surged, ignition of the fuel that went through the air channel occurred. After that, the flame covered all the fuel and went beyond the internal structure, however, it was almost instantly blown away by the oncoming air stream. Because of this situation, an unusual phenomenon appeared, which was called the fireball. This “Buk” inversion trace is also capable of transmitting.
Vivid afterburner trail
Modern fighter aircraft have an engine that is equipped with adjustable nozzles, classified as supersonic. When the afterburner is connected, the pressure at the nozzle exit is much higher than that of the surrounding air masses. If you analyze the space at a considerable distance from the nozzle, the pressure gradually equalizes. This aspect during the movement of the aircraft leads to increased gas production, which leads to the formation of a bright inversion trail from the aircraft that appears when the aircraft moves.