Townsend's (1980) model of wind-to-wave energy transfer, which is based on a
putative interpolation between an inner, viscoelastic approximation and an outer,
rapid-distortion approximation and predicts an energy transfer that is substantially
larger (by as much as a factor of three) than that predicted by Miles's (1957) quasi-laminar
model, is revisited. It is shown that Townsend's interpolation effectively
imposes a rapid-distortion approximation throughout the flow, rather than only in
the outer domain, and that his asymptotic (far above the surface) solution implicitly
omits one of the two admissible, linearly independent solutions of his perturbation
equations. These flaws are repaired, and Townsend's dissipation function is modified
to render the transport equation for the perturbation energy of the same form as
those for the perturbation Reynolds stresses. The resulting wind-to-wave energy
transfer is close to that predicted by Townsend's (1972) viscoelastic model and other
models that incorporate the perturbation Reynolds stresses, but somewhat smaller
than that predicted by the quasi-laminar model. We conclude that Townsend's (1980)
predictions, although closer to observation than those of other models, rest on flawed
analysis and numerical error.