Plesset

Plesset is a surname most notably associated with Milton S. Plesset, an American physicist whose work in fluid dynamics contributed to the theory of bubble dynamics. He is best known for co-developing the Rayleigh–Plesset equation, a fundamental model for the radial motion of a spherical gas bubble in a liquid under time-varying external pressure.

The Rayleigh–Plesset equation describes how the bubble radius R(t) evolves due to inertia, viscous damping, surface tension, and the internal gas pressure, in response to the external pressure field p∞(t). The standard form for an incompressible, infinite liquid is ρ (R d^2R/dt^2 + 3/2 (dR/dt)^2) = p_g - p∞ - 4 μ dR/dt / R - 2 σ / R, where ρ is the liquid density, μ its viscosity, σ the surface tension, and p_g the gas pressure inside the bubble. p_g is typically modeled with a polytropic or other equation of state. The equation captures the balance of forces on the bubble surface and is used to predict bubble growth and collapse under dynamic loading.

Applications and significance are broad: it is a central tool in cavitation research, bubble dynamics in liquids, sonolumescence, and medical or industrial contexts where acoustic or transient pressures drive bubble behavior. The equation is named for Lord Rayleigh and Milton S. Plesset, reflecting contributions across decades to understanding bubble dynamics.

See also: Rayleigh–Plesset equation; cavitation; bubble dynamics; sonolumescence; ultrasound.