History Of Fluid Mechanics 556d2j

Table of content Subject Introduction Archimedes Abū Rayhān al-Bīrūnī Leonardo da Vinci Evangelista Torricelli Edme Mariotte Blaise Pascal Isaac Newton Daniel Bernoulli Leonhard Euler Jean le Rond d'Alembert A ntoine Chézy Pierre Louis Georges St. Venant Poiseuille Gaspard Riche de Prony Johann Albert Eytelwein Jean Nicolas Pierre Hachette Lord Rayleigh Osborne Reynolds Navier and Stokes Ludwig Prandtl

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Introduction The historical development of fluid mechanics is roughly sketched out, based on the most important contributions of a number of scientists and engineers. The presentation does not claim to give a complete picture of the historical developments: this is impossible owing to the constraints on allowable space in this section. The aim is rather to depict the development over centuries in a generally comprehensible way. In summary, it can be said that already at the beginning of the nineteenth century the basic equations with which fluid flows can be described reliably were known. Solutions of these equations were not possible owing to the lack of suitable solution methods for engineering problems and therefore technical hydraulics developed alongside the field of theoretical fluid mechanics. In the latter area, use was made of the known contexts for the flow of ideal fluids and the influence of friction effects was taken into consideration via loss coefficients, determined empirically. For geometrically complicated problems, methods based on similarity laws were used to generalize experimentally achieved flow results. Analytical methods only allowed the solution of academic problems that had no relevance for practical applications. It was not until the second half of the twentieth century that the development of suitable methods led to the numerical techniques that we have today which allow us to solve the basic equations of fluid mechanics for practically relevant flow problems. Parallel to the development of the numerical methods, the development of experimental techniques was also pushed ahead, so that nowadays measurement techniques are available which allow us to obtain experimentally fluid mechanics data that are interesting for practical flow problems.

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Archimedes (287 BC –212 BC) formulated the laws of buoyancy and applied them to floating and submerged bodies, actually deriving a form of the differential calculus as part of the analysis. Applications: Sailing ships, irrigation systems

Abu Rayhan Al-Biruni (973-1048) Al-Biruni and al-Khazini were the first to apply experimental scientific methods to fluid mechanics, especially in the field of fluid statics, such as for determining specific weights. Biruni discovered that there is a correlation between the specific gravity of an object and the volume of water it displaces.

Leonardo da Vinci (1452-1519) He derived the equation of conservation of mass in one-dimensional steady flow. His notes contain accurate descriptions of waves, jets, hydraulic jumps, eddy formation, and both low-drags (streamlined) and high-drag (parachute) designs.

Evangelista Torricelli (1608 –1647) Torricelli's chief invention was the mercurial barometer, which arose from solving an important practical problem. This was the first barometer. This discovery has perpetuated his fame, and the Torr, a unit of pressure commonly used in vacuum measurements, was named in his honor

Edme Mariotte (1620-1684) He is founded on a great variety of well-conducted experiments on the motion of fluids, performed at Versailles and Chantilly. He built the first wind tunnel and tested models in it.

Blaise Pascal (1623,1662) Pascal's work in the fields of the study of hydrodynamics and hydrostatics centered on the principles of hydraulic fluids. His inventions include the hydraulic press (using hydraulic pressure to multiply force) and the syringe. he 3

made important contributions to the study of fluids, and clarified the concepts of pressure and vacuum by generalizing the work of Evangelista Torricelli.

Isaac Newton (1642-1727) He postulated his laws of motion and the law of viscosity of the linear fluids now called newtonian .

Daniel Bernoulli (1700-1782) Together Bernoulli and Euler tried to discover more about the flow of fluids. In particular, they wanted to know about the relationship between the speed at which blood flows and its pressure. Bernoulli's method of measuring pressure is still used today in modern aircraft to measure the speed of the air ing the plane; that is its air speed.

Leonhard Euler (1707-1783) Euler developed both the differential equations of motion of fluids and their integrated form, now called the Bernoulli equation. This calculus was first applied to the motion of water by d'Alembert, and enabled both him and Euler to represent the theory of fluids in formulae restricted by no particular hypothesis.

Jean le Rond d'Alembert (1717-1783) D’Alembert used the equation developed by Euler to show his famous paradox: that a body immersed in a frictionless fluid has zero drag.

Antoine Chézy (1718-1798) First to express the mean flow velocity in of channel roughness, hydraulic radius, and bed slope. This formula describes the mean flow velocity of steady, turbulent open channel flow 4

Pierre Louis Georges Dubuat (1734–1809) One of the most successful labourers in the science of hydrodynamics at this period . he published, in 1786, a revised edition of his Principes d'hydraulique, which contains a satisfactory theory of the motion of fluids, founded solely upon experiments.

St. Venant (1797 - 1886 ) Formulated the equations of unsteady flow in open channels.

Poiseuille(1797-1869) In 1838 he experimentally derived, and in 1840 and 1846 formulated and published, Poiseuille's law. This concerns the voluminal laminar stationary flow of an incompressible uniform viscous liquid (so-called Newtonian fluid) through a cylindrical tube with constant circular cross-section.

Gaspard Riche de Prony (1755–1839) The theory of running water was greatly advanced by the researches he had done. he succeeded in drawing up general formulae, which afforded a simple expression for the velocity of running water.

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Johann Albert Eytelwein (1764-1848) He showed theoretically that a water wheel will have its maximum effect when its circumference moves with half the velocity of the stream.

Jean Nicolas Pierre Hachette (1769-1834) JNP Hachette in 1816-1817 published memoirs containing the results of experiments on the spouting of fluids and the discharge of vessels.

Lord Rayleigh (1842-1919) He proposed the technique of proposed the technique of while he was trying to understand why the sky is blue. Application: Dimensional analysis is used to derive relationships between the physical quantities that are involved in a particular phenomenon that one wishes to understand and characterize.

Osborne Reynolds (1842-1912) published the classic pipe experiment in 1883 which showed the importance of the dimensionless Reynolds number named after him.

Navier (1785-1836) and Stokes (1819-1903) The Navier–Stokes equations, describe the motion of fluid substances. These equations arise from applying Newton's second law to fluid motion, together with the assumption that the fluid stress is the sum of a diffusing viscous term (proportional to the gradient of velocity), plus a pressure term. Application: The equations are useful because they describe the physics of many things of academic and economic 6

interest. They may be used to model the weather, water flow in a pipe, air flow around a wing.

Ludwig Prandtl (1875-1953) Prandtl pointed out that fluid flows with small viscosity (water and air flows) can be divided into a thin viscous layer, or boundary layer, near solid surfaces and interfaces, patched onto a nearly inviscid outer layer, where the Euler and Bernoulli equations apply.

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