The Scruton number Sc is an important parameter for vortex-induced vibration (excitation) of structures, vibrations caused by rain or wind, dry inclined cable galloping, and wake galloping, the unstable airflow that forms around bridge cables and other cylindrically-structured buildings. It is named after Christopher "Kit" Scruton, a British industrial dynamics engineer.
It is defined by:
|is the structural damping expressed by the logarithmic damping decrement,|
|is the effective mass per unit length,|
|is the density of the air, or liquid,|
|is the characteristic width of the structure.|