Physicist and engineer — Osborne Reynolds (1842–1912) was an Irish-born engineer and physicist, for many years professor of engineering at Owens College, Manchester. He is one of the fathers of modern fluid dynamics. In the famous experiment of 1883 he injected a thread of dye into water flowing through a glass tube, observing the transition from ordered (laminar) to chaotic (turbulent) motion as the velocity increased. From these studies he introduced the dimensionless number that bears his name, which allows the flow regime to be predicted by comparing inertial and viscous forces. He also made fundamental contributions to lubrication theory and proposed the decomposition of quantities into mean value and fluctuation, the basis of the RANS equations still used today to model turbulence.
Fun fact
The original apparatus of his 1883 experiment, with the thread of dye dissolving into turbulence, is still preserved and working at the University of Manchester.
Theories and contributions
- Reynolds number — Ratio of inertial to viscous forces that characterises the flow regime: .
- Laminar-turbulent transition — Experimentally demonstrated the transition from ordered to turbulent motion beyond a critical value of .
- Reynolds decomposition — Separation of velocity and pressure into mean value and fluctuation, the basis of the RANS equations of turbulence.
Present in chapters
Linked atoms
1 linked atom.