Non-linear, High Frequency Sound Waves

摘要

The theory of relatively undistorted waves (VarleyCumberbatch, 1966) is used to discuss finite amplitude, radially symmetric, isentropic waves in fluids. A simple asymptotic expansion which generalizes that used in the linear theory of geometrical acoustics to take into account non-linear phenomena is given. The first and second terms in this expansion are calculated. The first term agrees with a hypothesis of Whitham (1956). The theory is used to discuss the flow produced by a pulsating sphere.