Wind engineering in bridges
Introduction
In engineering, a wind tunnel or wind tunnel is a research tool developed to assist in the study of the effects of air movement around solid objects. With this tool, the conditions that the object of the research will experience in a real situation are simulated. In a wind tunnel, the object or model remains stationary while the passage of air or gas is propelled around it. It is used to study the phenomena that occur when air washes over objects such as airplanes, spacecraft, missiles, cars, buildings or bridges.
History of wind tunnels
The English military engineer Benjamin Robins (1707-1751) invented a rotating arm apparatus to perform resistance experiments within aviation theory.
George Cayley (1773-1857) also used a rotating arm to measure the resistance and lift of various blades. Its rotating arm was 5 feet long and achieved tip speeds of between 10 and 20 feet per second. Armed with data from the arm tests, Cayley built a small glider that is believed to have been one of the first heavier-than-air vehicles successfully used to carry a man in history. However, the rotating arm does not produce an airflow that impacts the test shapes at normal incidence. Centrifugal forces and the fact that the object is moving through its own wake mean that a detailed examination of the airflow is difficult. Francis Herbert Wenham (1824-1908), a Council Member of the Royal Aeronautical Society of the United Kingdom, fixed these problems, designing and operating the first wind tunnel in 1871.[1].
A wind tunnel known as an "aerodynamic tube" was designed and built by Tsiolkovski in 1897.
Once this discovery came to light, detailed technical data was quickly extracted. Wenham and his colleague Browning are credited with many fundamental discoveries, including the revelation of the beneficial effects of a high aspect ratio. Carl Rickard Nyberg") used a wind tunnel when designing his Flugan") in 1897.
In experiments, Englishman Osborne Reynolds (1842-1912) of the University of Manchester demonstrated that the air flow pattern on a scale model would be the same for the real vehicle if a certain flow parameter were the same in both cases. This factor, now known as the Reynolds Number, is a basic parameter in the description of all fluid-flow situations, including the shapes of the flow patterns, the ease of heat transfer and the presence of turbulence. This comprises the central scientific justification for the use of models in wind tunnels when simulating real-life phenomena.