utorok 28. februára 2012

History of aviation (part 2)

Early attempts

Early flying machines

Flight automaton in Greece

Around 400 BC, Archytas, the Greek philosopher, mathematician, astronomer, statesman and strategist, designed and built a bird-shaped, apparently steam powered model named "The Pigeon" (Greek: Περιστέρα "Peristera"), which is said to have flown some 200 meters. According to Aulus Gellius, the mechanical bird was suspended on a string or pivot and was powered by a "concealed aura or spirit".

Hot air balloons, glider and kites in China

The Kongming lantern (proto hot air balloon) was known in China from ancient times. Its invention is usually attributed to the general Zhuge Liang (180–234 AD, honorific title Kongming), who is said to have used them to scare the enemy troops:

An oil lamp was installed under a large paper bag, and the bag floated in the air due to the lamp heating the air. ... The enemy was frightened by the light in the air, thinking that some divine force was helping him.

However, the device based on a lamp in a paper shell is documented earlier, and according to Joseph Needham, hot-air balloons in China were known from the 3rd century BC.

In the 5th century BCE Lu Ban invented a 'wooden bird' which may have been a large kite, or which may have been an early glider.

In 1st century AD, when Wang Mang tried to recruit specialist as scout to Xiong Nu, a man binding himself with bird feather glided about 100 meters, but finally landed.

Yuan Huangtou, Ye, first manned kite glide to take off from a tower — 559

During the Yuan dynasty (13th c.) under rulers like Kublai Khan, the rectangular lamps became popular in festivals, when they would attract huge crowds. During the Mongol Empire, the design may have spread along the Silk Route into Central Asia and the Middle East. Almost identical floating lights with a rectangular lamp in thin paper scaffolding are common in Tibetan celebrations and in the Hindu festival of lights, Diwali. However, there is no evidence that these were used for human flight. Read more...part 3

History of aviation (part 1)

The history of aviation has extended over more than two thousand years from the earliest attempts in kites and gliders to powered heavier-than-air, supersonic and hypersonic flight.

The first form of man-made flying objects were kites. The earliest known record of kite flying is from around 200 BC in China, when a general flew a kite over enemy territory to calculate the length of tunnel required to enter the region. Yuan Huangtou, a Chinese prince, survived by tying himself to the kite.

Leonardo da Vinci's (15th c.) dream of flight found expression in several designs, but he did not attempt to demonstrate his ideas by actually constructing them.

With the efforts to analyze the atmosphere in the 17th and 18th century, gases such as hydrogen were discovered which in turn led to the invention of hydrogen balloons. Various theories in mechanics by physicists during the same period of time, notably fluid dynamics and Newton's laws of motion, led to the foundation of modern aerodynamics. Tethered balloons filled with hot air were used in the first half of the 19th century and saw considerable action in several mid-century wars, most notably the American Civil War, where balloons provided observation during the Battle of Petersburg.

Experiments with gliders provided the groundwork for heavier-than-air craft, and by the early 20th century advances in engine technology and aerodynamics made controlled, powered flight possible for the first time. Read more...part 2