Frank S. Henyey

Improved linear representation of ocean surface waves

We apply the idea of choosing new variables that are nonlinear functions of the old in order to simplify calculations of irrotational, surface gravity waves. The usual variables consist of the surface elevation and the surface potential and the transformation to the new variables is a canonical (in Hamilton sense) one so as to maintain the Hamiltonian structure of the theory.

Energetics of borelike internal waves

The net integrated energy flux into a train of internal waves is evaluated in a two-layer model. The nonzero value for this integral results from the difference in the stratification between the initial and final state, similar to the energy supply to a surface bore. We apply this expression to waves measured by Wesson and Gregg [1988] in the Strait of Gibraltar and to waves measured by Farmer and Smith [1980] in Knight Inlet. We find the energy supply to be important to the energetics, but the data do not allow a definitive test of the conjecture that the primary energy balance is between this supply and dissipation. We contrast our conjecture to the solitary-wave considerations of Bogucki and Garrett [1993].

Moment‐equation and path‐integral techniques for wave propagation in random media

Differential equations for all moments of the field of a wave propagating through a random medium are derived under the parabolic approximation and the Markov approximation, but including anisotropy in the random medium and a deterministic background refractive index. Mathematical equivalence is demonstrated between these moment equations and path‐integral expressions for the moments obtained under the same approximations. A discussion of approximations that are weaker than Markov is given.

Flow modification by polymers in strong elongational flows

Flow modification by dilute solutions of polymers in strong elongational flows is analyzed using a two‐state model according to which the polymer contribution to the stress balance in the fluid is negligible as long as the polymers are in their coiled state (or are in the process of stretching) and becomes significant as they approach their steady configuration corresponding to an almost fully stretched state. The flow field is separated accordingly into weakly and strongly modified regions and, using mass and momentum conservation considerations, we obtain the flow profiles in these regions. Our prediction of a dip in the velocity and strain rate profiles agrees with experimental observations.

Representation of the supercritical Pomeron propagator

Abstract Analytic continuation in the bare Pomeron intercept is discussed in the context of a representation of the Pomeron propagator derived by the renormalization-group approach. When the bare intercept is above the critical value, the leading singularity turns out to be a branch point fixed at J = 1. The resulting cross section grows like (ln s ) r . where r is a ratio of critical exponents. In the one- and two-loop approximations, r ≈ 1.