# Second-order boundary corrections to the radial acoustic eigenvalues for a spherical cavity

Published: August 17, 2012

Keith A. Gillis

### Abstract

We calculated the eigenvalues of the radially-symmetric acoustic modes of a gas-filled, spherical cavity to order (δT/a)2, where δT is the thickness of the thermal boundary layer and a is the radius of the cavity. Our results are consistent with high-precision acoustic measurements made to re-determine the Boltzmann constant.
Citation: Metrologia
Volume: 49
Issue: 6
Pub Type: Journals

### Keywords

Boltzmann constant, spherical resonator, speed of sound, second order, radial modes, eigenvalues
Created August 17, 2012, Updated February 19, 2017