Index Catalog // ScholarsArchive@OSU

Creator:: Smyth, William D.
Abstract:: The envelope function for Kelvin–Helmholtz billows growing from a point disturbance is derived on the basis of linear perturbation theory. The result describes an elliptical patch of billows that expands linearly in time as the billows grow. An analytical model of the dispersion relation is used to derive quantitative expressions...
Resource Type:: Article
Full Text:: normal modes. In general, the impulse response function can be written as f (x, y, z, t)= ∫ ∞ −∞ f̂ (z

Creator:: Smyth, William D.
Abstract:: The growth of secondary vortices on the braids separating Kelvin–Helmholtz billows is investigated via numerical simulations. The similarity theory of Corcos & Sherman (1976) is extended to include mixing processes with Prandtl number greater than unity, and is shown to provide a useful description of the physics of the braid...
Resource Type:: Article
Full Text:: weakly stratified shear flow By WILLIAM D. SMYTH College of Oceanic and Atmospheric Sciences, Oregon

Creator:: Smyth, William D.
Abstract:: A sequence of direct simulations is used to study mechanisms for the growth of secondary circulations and turbulence in stratified shear flows. Five cases are examined, of which four deliver Holmboe waves as the primary instability and the fifth generates Kelvin-Helmholtz billows. Secondary circulations range in strength from weak, laminar...
Resource Type:: Article
Full Text:: circulations in Holmboe waves William D. Smyth College of Oceanic and Atmospheric Sciences, Oregon State

Creator:: Smyth, William D.
Abstract:: Direct numerical simulations of turbulence resulting from Kelvin{Helmholtz instability in stratified shear flow are used to examine the geometry of the dissipation range in a variety of flow regimes. As the buoyancy and shear Reynolds numbers that quantify the degree of isotropy in the dissipation range increase, alignment statistics evolve...
Resource Type:: Article
Full Text:: : f(x+ Lx, y, z) = f(x, y + Ly, z) = f(x, y, z), (5) in which f is any solution field and the

Creator:: Smyth, William D. and Ruddick, Barry
Abstract:: In this paper the authors investigate the action of ambient turbulence on thermohaline interleaving using both theory and numerical calculations in combination with observations from Meddy Sharon and the Faroe Front. The highly simplified models of ambient turbulence used previously are improved upon by allowing turbulent diffusivities of momentum, heat,...
Resource Type:: Article
Full Text:: at a Baroclinic Front WILLIAM D. SMYTH College of Oceanic and Atmospheric Sciences, Oregon State

Creator:: Smyth, William D. and Kimura, Satoshi
Abstract:: The linear stability of a double-diffusively stratified, inflectional shear flow is investigated. Double-diffusive stratification has little effect on shear instability except when the density ratio R[subscript]ρ is close to unity. Double-diffusive instabilities have significant growth rates and can represent the fastest-growing mode even in the presence of inflectionally unstable shear...
Resource Type:: Article
Full Text:: -Diffusive, Stratified Shear Layer WILLIAM D. SMYTH AND SATOSHI KIMURA College of Oceanic and Atmospheric

Creator:: Inoue, Ryuichiro and Smyth, William D.
Abstract:: The dependence of mixing efficiency on time-varying forcing is studied by direct numerical simulation (DNS) of Kelvin–Helmholtz (KH) instability. Time-dependent forcing fields are designed to reproduce a wavelike oscillation by solving the equations of motion in a tilted coordinate frame and allowing the tilt angle to vary in time. Mixing...
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Full Text:: Columbia, Canada WILLIAM D. SMYTH College of Oceanic and Atmospheric Science, Oregon State University

Creator:: Smyth, William D. and Moum, James N.
Abstract:: Turbulence resulting from Kelvin–Helmholtz instability in layers of localized stratification and shear is studied by means of direct numerical simulation. Our objective is to present a comprehensive description of the turbulence evolution in terms of simple, conceptual pictures of shear–buoyancy interaction that have been developed previously based on assumptions of...
Resource Type:: Article
Full Text:: 2000 Length scales of turbulence in stably stratified mixing layers William D. Smytha) and James N

Creator:: Smyth, William D. and Moum, James N.
Abstract:: Kelvin-Helmholtz (KH) instability, characterized by the distinctive finite-amplitude billows it generates, is an important mechanism in the development of turbulence in the stratified interior of the ocean. In particular, it is often assumed that the onset of turbulence in internal waves begins in this way. Clear recognition of the importance...
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Full Text:: William Thomson (Lord Kelvin, 1824–1907) of Glasgow and Hermann von Helmholtz (1821–1894) of Berlin

Creator:: Smyth, William D. and Moum, James N.
Abstract:: Direct numerical simulations of turbulence resulting from Kelvin–Helmholtz instability in stably stratified shear flow are used to study sources of anisotropy in various spectral ranges. The set of simulations includes various values of the initial Richardson and Reynolds numbers, as well as Prandtl numbers ranging from 1 to 7. We...
Resource Type:: Article
Full Text:: 2000 Anisotropy of turbulence in stably stratified mixing layers William D. Smytha) and James N. Moum

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