Osborne Reynolds

Osborne Reynolds (1842–1912) was an Irish-born British engineer and physicist whose experiments and analysis established the importance of the Reynolds number in distinguishing laminar from turbulent flow.

George Gabriel Stokes: George Gabriel Stokes was an Irish mathematician and physicist whose work shaped fluid mechanics and mathematical physics. Stokes’s equations describe viscous fluid motion that Reynolds investigated experimentally.
Reynolds number: The dimensionless ratio of inertial to viscous forces in a flowing fluid. Reynolds used this ratio to compare flows and identify transitions between orderly and irregular motion.
Reynolds's pipe-flow experiment: A nineteenth-century experiment that injected colored dye into water flowing through a glass tube. It demonstrated that dye remains in a thread at low speeds but spreads irregularly above a critical condition.
Turbulence modeling: The use of mathematical approximations to predict turbulent fluid motion in engineering and science. Reynolds-averaged equations created a foundation for practical models of turbulent flow.
William Froude: William Froude was an English engineer who developed methods for predicting ship performance using scale models. Froude’s model-testing work parallels Reynolds’s use of experiments to establish engineering similarity.
Laminar flow: Fluid motion in which neighboring layers move smoothly with limited mixing across them. Reynolds’s pipe experiments showed this orderly regime at low Reynolds numbers.
Reynolds stress: An effective stress in averaged fluid equations arising from correlations between velocity fluctuations. It is the central extra term Reynolds derived when formulating equations for mean turbulent motion.
Computational fluid dynamics: The numerical simulation of fluid motion using discretized governing equations. Modern simulations rely on the flow regimes and averaged equations clarified by Reynolds.
John William Strutt, 3rd Baron Rayleigh: John William Strutt, Lord Rayleigh, was a British physicist known for foundational work in acoustics, optics, and fluid dynamics. Rayleigh developed mathematical treatments of fluid instability alongside Reynolds’s experimental investigations.
Turbulent flow: Fluid motion characterized by irregular fluctuations, vortices, and enhanced mixing. Reynolds’s dye experiments made the onset of this regime visible in pipes.

Linked from 4 pages