What is the Largest Flying Animal that Ever Lived?

Animal flight means that there are many types of animals in the animal world with flight capabilities, of which birds are the most. The invention of the plane was inspired by birds in many ways.

Animal flight

In the process of animal evolution and development, flying animals are the first to gain the ability to fly. In terms of vertebrates, Mesozoic pterosaurs are famous flying reptiles, but they became extinct 68 million years ago. Flying lizards, moles, etc. all have varying degrees of gliding ability. Bats in birds and mammals are a group of higher vertebrates that acquire perfect flight capabilities.

The structure of the animal's body has undergone significant changes in the course of adapting to flight. As far as the structure of the wing, the main flying organ of flying animals, is concerned, the development process from simple to complex, from low to high. Some short-distance gliding animals have not yet formed true wings, but some parts of the body are deformed into broad membranes to support their weight in the air and glide. For example: the "wings" of flying fish are actually developed pectoral fins. The tail fins sway into the air by violently swinging the water. The rapid swing of the pectoral fins can glide 100 to 150 meters against the water surface within 18 seconds. Membrane web, gliding by fins for dozens of meters when climbing tree ends; flying lizard's body skin expands into a wing membrane and connects with limbs, which can glide for a distance of 60-70 meters. Insects, birds, and bats are animals with fluttering wings. In the evolution process, they obtained flying organs in different ways. The wings of the insects are born on the back of the 2nd and 3rd thorax, and are elastic by 1 or 2 pairs. The wings of birds and bats evolved from the forelimbs. The phalanges of the bat's forelegs are particularly long. The entire phalanges, humerus, hind limbs and tailbone are covered with thin and flexible skin membranes. The forelimbs can be used to fly the membranes.

Structure and function of bird wing Bird wing (Figure 1) is the main organ adapted to flight. The wing's bones are thin and light, and there is inflation. Many bones merge and disappear to adapt to flying life. This is particularly manifested in the deformation of the forelimbs: the hand bones (carpal bones, metacarpals, and phalanges) are simplified and merged, and the forelimbs can only perform joint movements of folded wings and stretched wings on a plane, which is conducive to the formation of a powerful under the control of the pectoral muscle Fight against the air as a whole. The hair feathers that grow on the wings are an important part of the wings. The ones that are born on the hand bones are called primary flying feathers, and those that are born on the forearms are called secondary flying feathers. They produce different forces when fanning their wings. The former generates thrust and the latter generates lift. In addition, a small tuft of feathers is born at the wing corner (wrist) of the bird wing, which also plays an important role in flight control. Each flying feather is composed of a shaft and a blade. The base of the feather shaft penetrates deep into the skin, and the feather piece is composed of many feather branches that extend parallel to the sides of the feather shaft. Each branch has densely formed rows of feathery twigs on both sides, with hook processes, which are hooked to each other, thus forming a tough and elastic

Exploration of fixed-wing aircraft After the 1870s, people gradually focused on the development of fixed-wing aircraft, and flight exploration entered the research stage of fixed-wing aircraft. First of all, it faces the problem of reasonable selection of the lifting surface. There are two ways to solve it: one is to examine the structure of the bird's wing and its gliding law; the other is to explore the aerodynamic characteristics of the lifting surface such as the kite. Then the knowledge gained from two aspects is put into experiment. Bird wing is a natural and effective lifting surface, and developers of fixed-wing aircraft have imitated bird wing and tested it in flight practice. The bird's bow-shaped curved wings almost became the standard airfoil of early fixed-wing aircraft. Aerodynamicists are also engaged in research and experiments in this area. British aerodynamicist H. Phillips has drawn some curved airfoils through original wind tunnel experiments. American aviation pioneer SP Langley had experimented with bird wings hanging on a rotating arm. People tried to find out the airfoil suitable for the use of modern aircraft through these researches and experiments. Later, they obtained useful aerodynamic knowledge through the systemic research on bird wings, thus getting rid of the simple imitation of bird wings. However, people's exploration of the secrets of bird flight has not ended. The aerodynamicist .. Zhukovsky, the glider master O. Li Lindal, and the aircraft inventor Wright brothers have all studied birds. Books on bird flight also continue to appear. For the first time, Zhukovsky's On Flight of Birds analyzes flight dynamics. Others look for models from flying animals directly from the perspective of bionics. The large gliders that appeared in the 1850s were designed to mimic the shape of large wingspan seabirds such as albatross. While conducting a large number of gliding experiments, Li Lindal also conducted a systematic study of bird flight. His works, such as "The Flight of Birds-The Basics of Aviation," provided valuable information for later aircraft developers.

Birds and airplanes Airplane flight and bird flight are similar. Bird flight technology has been inherited and developed by aircraft. Comparing the eagle and the aircraft, both have a similar and complete set of devices to improve aerodynamic performance: small wings and leading edge slats. When the eagle drum wings, the connection angle of the wings is increased to increase the lift, and the gap formed between the small wings of the wings and the wing body allows the airflow to flow close to the back of the wings to prevent turbulence. The leading edge slat of the aircraft wing expands during take-off and landing and high angle of attack flight, so that the high-pressure airflow from the lower wing surface flows through the wing slit to the upper wing surface, blows away the turbulence in the surface layer, increases the critical angle of attack, and Prevent stalls. Slit wingtips and winglets. The slotted wing tip of the eagle's outer wing is actually a single winglet, which plays a role in reducing the strength of the wing tip tail vortex. The aircraft has winglet winglets to reduce the wing tip vortex intensity and induce drag. flaps. The leading edge of the inner wing of the hawk droops in flight, increasing the camber of the wing to increase lift, while the leading edge flap of the aircraft is set for the same purpose.

bibliography

WN Mcfaroland et al., Vertebrate Life, Macmillan Publ. Co., New York, 1979.

JCWeltu, The Life of Birds, Saunders College Publ., Philadelphia, 1979.

JZYoung, The Life of Vertebrates, Clarendon Press, Oxford, 1981.