Helicopter University
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Helicopter University

Helicopter University

 

LomonosovOur great compatriot, scientist, inventor and poet Mikhail Lomonosov in the early 1754 was made in the message of the Russian Academy of Sciences, which is recorded in the minutes of the meeting of the Academy as follows:

"Mr. Advisor and Professor Lomonosov Assembly introduced on a small machine that would raise her up thermometers and other small tools, weather, and suggested drawing thereof as the machine; In order for the Lord deliberative signified his performance tested and put the office of the Academy of Sciences report IN request to soblagsivoleno had spoken to order a car according to the attached herewith drawing for the experience of this invention to make a poster of his master in looking Futsiusom master. And about the above in mind the report of the academic meeting in March 4 1754 days of "

 

Thus, we see that the idea of ​​creating the world's first flying machine heavier than air came in Lomonosov in connection with the need to study the upper atmosphere.

A drawing of the "airfield machine" of the Lomonosov helicopter is presented. This first helicopter in the world is shown at the time of the test, after it was previously balanced with weights on a beam scale.

The minutes from the Academy in July 1 1754 was written:
"The highly respected adviser Lomonosov showed the machine he invented, which he called the airdrome (air-to-air), which should be used so that, with the help of wings moving horizontally in different directions by the force of the spring, which is usually supplied with the watch, press the air (throw it down ), Why the machine will go up to the upper layers of the air, so that it is possible to examine the conditions (state) of the upper air by means of meteorological machines (devices) attached to this aerodrome machine. The machine was suspended on a cord stretched over two blocks and held in balance by weights suspended from the opposite end. As soon as the spring was started, [the machine] rose in height and therefore promised the achievement of the desired action. "

Looking at the drawing, we see that the model had two coaxial four-bladed rotor, which rotate in opposite directions.

Why is this done?

In order to set in motion any body need power. The force results from interaction of at least two bodies. And the power of action of the first body to the second-largest force is the impact of the second body to the first, but has the opposite direction. Wing, for example, creates the lifting force by interacting with the air. It discarding air down itself receives a lifting force directed upwards. This second response force is called the reaction force.

If the force passes through the center of gravity of the body, the body moves forward. If a force acts on the body away from the center of gravity, the body also receives a rotational motion around gravity center. In this case we say that the body is rotated under the action of force. The magnitude of the torque can be calculated if we multiply the amount of force at its shortest distance to the center of gravity (on the shoulder of her actions).

 

Lomonosov helicopter

Just as every force opposed to the reactive force and moment of force entails the appearance of reluctance torque.

Consider the emergence of the jet moment as an example.

Shows a propeller, which can rotate freely on a support.

If screw A force is exerted through the center of gravity lies on the axis of rotation of the screw, the screw without rotation, with the stand will begin to move in the direction of the force. Reactive vultures in will affect the finger in the opposite direction.

Where, in this case the reaction force? The reaction force in this case will act from the rotor blade to the arm.

It will occur while the reaction torque acting on the stand? Of course not.

 

University 2 helicopter

Let the torque to the screw be communicated not by hand, but by a clock spring fixed at one end on the stand, and rigidly connected to the other by a screw. Being previously twisted, the spring will begin to unwind and rotate the screw, telling it the MKR torque, and the stand, telling it the L7P jet torque. Moment Mr is equal in magnitude to Mkr, but opposite in direction. 

 

With the action of reactive moment and faced Lomonosov once I started to make its model. In order to avoid rotation of the shell model, Lomonosov found ingeniously simple solution, which is still one of the classic ways to repay the reaction moment on the helicopter.

"Aerodromic machine" Lomonosov had two screws rotating in opposite directions. And if the reaction torque from one rotating screw sought chassis cars in one direction, the reactive torque from the second screw it sought to turn the body to the other side. And they are the same and the screws were rotated with equal speed, their reactive points are equal and therefore cancel each other. Housing machines in this case remains stationary during flight.

The idea of ​​establishing a helicopter appeared much earlier than the idea of ​​creating an aircraft.

Even in the writings of Leonardo da Vinci related to 1475 was found in the archives and libraries of Milan in the middle of the XIX century, there was a picture of the aircraft in which lift should create a rotating helical screw. Under the picture, and next to him with his hand, scientists have made the following entries:
"The frame screws must be made of iron wire, rope in thickness; distance from the circumference to the center should be equal to 8 elbows "(the elbow is about 60 cm. - AT).

"If the device is made properly, that is, from a strong canvas, the pores of which are carefully glued with starch, then I think that with its fast rotation such a screw will describe its cutting in the air and rise upwards. In this you can easily be convinced, dissecting the air with a wide thin ruler: then your hand will be forced to follow the direction of the edge of the ruler. The sail should be fixed on a frame of long thick reeds. You can make a small model of paper with an axis from a tightly twisted metal spring. If the spring is left to itself, it will make the screw rotate. "

Lomonosov did not know about the works of Leonardo da Vinci and all his work is done independently of him.

Difficulties theoretical, constructive and productive character for a long time hindered the improvement of the helicopter. Several decades helicopter was in the laboratories of scientists and experienced shops factories. Only thanks to the efforts of Russian scientists, many shortcomings were eliminated in the helicopter, the helicopter which opened the way for widespread use in all areas of the economy.

 

Istria aviation

External lightning protection is a system that intercepts lightning and discharges it into the ground, thereby protecting the building (structure) from damage and fire.
Most often, lightning rods are used to protect industrial structures. Cables are used for high-rise objects (radio towers, power lines) or buildings with an extensive network of underground utilities that interfere with the installation of rods.

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