In 1792, he began to make a series of experiments with a toy, which was the "bamboo dragonfly" introduced from China to Europe.
in p>1796, Kelly made the first aircraft-a relatively rotating model helicopter on the basis of scientific calculation.
in p>1799, at the age of 26, Kelly designed a sketch of an aircraft that almost had the main components of a modern aircraft. George Kelly? carved the sketch on a small silver plate. One side of the small silver plate is engraved with the explanation of various forces on the wing, and the other side is engraved with the sketch of the plane. This silver plate is now in the Science Museum in London. But the problem that has plagued Kelly for many years is that there is no suitable power. At that time, the steam engine was big and bulky, and it was impossible to send Kelly's plane into the sky. Therefore, Kelly still used flapping wings as the power and the way to generate lift. But the value of Kelly lies in that he is not satisfied with mastering the existing knowledge, but enriches his theoretical level through continuous experiments.
In p>184, Kelly studied the driving force of birds and tested a glider model on the rotating arm. Soon, he launched the winged projectile into the sea. Almost at the same time, he also designed a compound plane, with fixed wings on the wheelbarrow and flapping wings on the wing tips.
in p>187, Kelly studied the hot gas engine and another engine using gunpowder. In 188, Kelly developed "rotor" and "paddle wheel" aircraft, and in the same year designed a flapping wing machine.
in p>189, Kelly began to study the relationship between fish and what we call streamline today, and successfully manufactured the first full-scale glider in aviation history and made a test flight. In 189, his paper entitled "On Air Navigation" was published in the journal of natural philosophy. In this paper, he put forward very important scientific conclusions: 1. Define the four forces acting on heavier-than-air aircraft-lift, gravity, thrust and resistance; 2. The mechanism for determining the lift is separate from the thrust mechanism. At this point, Kelly has realized that bird wings not only have the function of propulsion, but also have the function of generating lift. If human aircraft use different devices to realize the above functions, it will be much easier than simply imitating the flight movements of birds. This important discovery laid the basic conception and theoretical foundation for the aircraft with fixed wings. In his paper, he repeatedly emphasized the importance of manufacturing fixed-wing aircraft, outlined the outline of modern aircraft in detail, and made important contributions to the emergence and formation of aerodynamic theory. He described the control surfaces such as fixed wing, tail, fuselage and elevator, explained the function of wing, and pointed out that proper stability should be obtained from carefully designing the wing surface to make it have a little angle; Then he mentioned that the aircraft must rise against the wind and have vertical and horizontal rudder surfaces. Kelly's paper also expounds the relationship between speed and lift, the reduction of wing load, tension and gravity, even the principle of internal combustion engine and the importance of streamlining to aircraft design.
in his theory, there is a passage explaining the basic principle of aircraft, which is still very incisive and accurate today, that is, "the whole problem of mechanical flight is to provide power to a flat plate, so that it can generate lift in the air flow and support a certain mass." His paper "On Air Navigation" is regarded by later generations as the starting line of aviation theory. Until 1848, when Kelly was 75 years old, there was still no news of a suitable engine with light weight. He felt that time was running out. The only thing he could try was unpowered manned flight, that is, flying with a glider, to prove his aerodynamic theory. So in 1849, he built a three-wing glider, let a 1-year-old child sit in a hanging basket and slide down the hill. Some people pulled the glider with ropes, and the plane flew for a distance against the breeze. This is the first manned glider tethered and towed flight in human history.
in p>1853, Kelly built a glider and installed a smart brake lever to fly freely in the first manned heavier-than-air aircraft in history. This time, he put his coachman in the cab, and there is no clear record of how far he flew. Interestingly, after the coachman got off the plane, he resigned. He said, Sir George, I want to remind you that I was hired by you to drive a car, not to fly. In that year, he wrote an article describing the flight of unmanned gliders and sent it to the French Aviation Society, entitled "Improved 1853 Rudder Glider". In 1971, a British pilot, Lieutenant Colonel Sparrow, built a glider exactly the same as that in 1971 according to Kelly's notes, which proved how successful Kelly's design was 118 years ago.
in p>1858, Kelly was 84 years old. Before he died, he was still banging in the workshop, hoping to make a light-weight engine, but he failed. Kelly's research work, especially his paper On Air Navigation, occupies an important position in the history of aviation development. For more than 1 years, it has been reprinted and regarded as a classic of aviation theory by future generations. Orville Wright, one of the inventors of aircraft, said in 1912 that their success was entirely due to the theory of aircraft heavier than air written by the British gentleman 1 years ago. He said, "Sir George Kelly?'s knowledge of aviation principles can be said to be unprecedented and unprecedented. Until the end of the 19th century, his published works were error-free, which was really the greatest document in the history of science." Wilbur Wright also said, "When we designed the plane, we completely adopted the very accurate calculation method proposed by Sir Kelly."
Kelly is not only interested in aviation, but also designed naval artillery shells for Great Britain, which were used during the Napoleonic Wars. In 187, he invented and patented a heat engine, which was widely used in industry. In 1825, Kelly designed a wheel with spokes for gliders, and this invention is still adopted by bicycles. In addition, he also invented the automatic railway braking device, and made many valuable contributions in acoustics, optics, electricity and sewer engineering.
on December 15th, 1857, Kelly died in Bloomton, Yorkshire. Shortly before his death, he wrote these two sentences: "here you are, friend who checks notes!" I have gone, I hope you can find the fire of wisdom in these graffiti. "