Книга: Strouhal Number: Dimensional Analysis, Dimensionless Quantity, Vincenc Strouhal, Vortex Shedding, Fluid Mechanics, Reynolds Number, Roshko Number, Metrology, Froude Number

High Quality Content by WIKIPEDIA articles! In dimensional analysis, the Strouhal number is a dimensionless number describing oscillating flow mechanisms. The parameter is named after Vincenc Strouhal, a Czech physicist who experimented in 1878 with wires experiencing vortex shedding and singing in the wind. The Strouhal number is an integral part of the fundamentals of fluid mechanics. For large strouhal numbers (order of 1), viscosity dominates fluid flow, resulting in a collective oscillating movement of the fluid 'plug'. For low strouhal numbers (order of 10?4 and below), the high-speed, quasi steady state portion of the movement dominates the oscillation. Oscillation at intermediate strouhal numbers is characterized by the buildup and rapidly subsequent shedding of vortices.