Claude-Louis Navier (born Claude Louis Marie Henri Navier; ; 10 February 1785 – 21 August 1836) was a French
civil engineer, affiliated with the
French government, and a
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...
who specialized in
continuum mechanics
Continuum mechanics is a branch of mechanics that deals with the deformation of and transmission of forces through materials modeled as a ''continuous medium'' (also called a ''continuum'') rather than as discrete particles.
Continuum mec ...
.
The
Navier–Stokes equations
The Navier–Stokes equations ( ) are partial differential equations which describe the motion of viscous fluid substances. They were named after French engineer and physicist Claude-Louis Navier and the Irish physicist and mathematician Georg ...
refer eponymously to him, with
George Gabriel Stokes.
Biography
After the death of his father in 1793, Navier's mother left his education in the hands of his uncle
Émiland Gauthey, an engineer with the
Corps of Bridges and Roads ''(Corps des Ponts et Chaussées)''. In 1802, Navier enrolled at the
École polytechnique, and in 1804 continued his studies at the
École Nationale des Ponts et Chaussées, from which he graduated in 1806. He eventually succeeded his uncle as ''Inspecteur general'' at the Corps des Ponts et Chaussées.
He directed the construction of bridges at Choisy, Asnières and Argenteuil in the Department of the Seine, and built a footbridge to the
Île de la Cité in
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
. His 1824 design for the
Pont des Invalides failed to leave a safety margin on top of his calculations, and after cracking the bridge had to be dismantled, destroying Navier's bridge-building reputation. He was chastised by a government committee for relying too much on mathematics.
In 1824, Navier was admitted into the
French Academy of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
. In 1830, he took up a professorship at the École Nationale des Ponts et Chaussées, and in the following year succeeded the exiled
Augustin Louis Cauchy as professor of
calculus
Calculus is the mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations.
Originally called infinitesimal calculus or "the ...
and
mechanics
Mechanics () is the area of physics concerned with the relationships between force, matter, and motion among Physical object, physical objects. Forces applied to objects may result in Displacement (vector), displacements, which are changes of ...
at the École polytechnique.
Contributions
Navier formulated the general
theory of elasticity in a mathematically usable form (1821), making it available to the field of construction with sufficient accuracy for the first time. In 1819 he succeeded in determining the ''zero line'' of mechanical stress, finally correcting
Galileo Galilei
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei ( , , ) or mononymously as Galileo, was an Italian astronomer, physicist and engineer, sometimes described as a poly ...
's incorrect results, and in 1826 he established the
elastic modulus
An elastic modulus (also known as modulus of elasticity (MOE)) is a quantity that describes an object's or substance's resistance to being deformed elastically (i.e., non-permanently) when a stress is applied to it.
Definition
The elastic modu ...
as a property of materials independent of the
second moment of area. Navier is therefore often considered to be the founder of modern
structural analysis
Structural analysis is a branch of solid mechanics which uses simplified models for solids like bars, beams and shells for engineering decision making. Its main objective is to determine the effect of loads on physical structures and their c ...
.
His major contribution, however, remains the
Navier–Stokes equations
The Navier–Stokes equations ( ) are partial differential equations which describe the motion of viscous fluid substances. They were named after French engineer and physicist Claude-Louis Navier and the Irish physicist and mathematician Georg ...
(1822), central to
fluid mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids (liquids, gases, and plasma (physics), plasmas) and the forces on them.
Originally applied to water (hydromechanics), it found applications in a wide range of discipl ...
.
His name is one of the
72 names inscribed on the Eiffel Tower.
Selected publications
* ''Rapport à Monsieur
Becquey et Mémoire sur les ponts suspendus. Notice sur le pont des Invalides'', chez Carillan Gœury, Paris, 183
(''read online'' (French language))* ''Résumé des leçons données à l'École des ponts et chaussées sur l'application de la mécanique à l'Établissement des constructions et des machines'', tome 1, ''Première partie contenant des leçons sur la résistance des matériaux, et sur l'établissement des constructions en terre, en maçonnerie et en charpente'', chez Carilian-Gœury 2nd édition), Paris, 183
(''read online'' (French language))* ''Résumé des leçons données à l'École des ponts et chaussées sur l'application de la mécanique à l'Établissement des constructions et des machines'', tome 2, ''Deuxième partie, leçons sur le mouvement et la résistance des fluides, la conduite et la distribution des eaux'', ''Troisième partie, leçons sur l'établissement des machines'', chez Carilian-Gœury 2nd édition), Paris, 183
(''read online'' (French language))* ''De l'établissement d'un chemin de fer entre Paris et Le Havre'', imprimerie Firmin-Didot, 182
(''read online'' (French language))* ''Mémoire sur les lois du mouvement des fluides'', lu à l'Académie royale des Sciences le 18 mars 1822, dans ''Mémoires de l'Académie des sciences de l'Institut de France - Année 1823'', Gauthier-Villars, Paris, 1827,
(''read online'' (French language))h1>
References
External links
data BnF : Claude Navier (1785-1836)*
{{DEFAULTSORT:Navier, Claude-Louis
1785 births
1836 deaths
Corps des ponts
École des Ponts ParisTech alumni
École Polytechnique alumni
French fluid dynamicists
Military personnel from Dijon
French physicists
Members of the French Academy of Sciences
Scientists from Dijon
Engineers from Dijon