29 citations · 135 across the 16 of their papers we have counts for
16 papers
Nonmodal growth and optimal perturbations in magnetohydrodynamic shear flows
Adrian E. Fraser, Alexis K. Kaminski, Jeffrey S. Oishi
In astrophysical shear flows, the Kelvin-Helmholtz (KH) instability is generally suppressed by magnetic tension provided a sufficiently strong streamwise magnetic field. This is of…
3D Simulations Demonstrate Propagating Thermohaline Convection for Polluted White Dwarfs
Imogen G. Cresswell, Adrian E. Fraser, Evan B. Bauer +2
Polluted white dwarfs (WDs) with small surface convection zones deposit significant concentrations of heavy elements to the underlying radiative interior, presumably driving thermo…
Evolution of Semi-convective Staircases in Rotating Flows: Consequences for Fuzzy Cores in Giant Planets
J. R. Fuentes, Bradley W. Hindman, Adrian E. Fraser +1
Recent observational constraints on the internal structure of Jupiter and Saturn suggest that these planets have ``fuzzy" cores, i.e., gradients of the concentration of heavy eleme…
Predicting the Slowing of Stellar Differential Rotation by Instability-Driven Turbulence
B. Tripathi, A. J. Barker, A. E. Fraser +2
Differentially rotating stars and planets transport angular momentum internally due to turbulence at rates that have long been a challenge to predict reliably. We develop a self-co…
Three-Dimensional Shear-Flow Instability Saturation via Stable Modes
B. Tripathi, P. W. Terry, A. E. Fraser +2
Turbulence in three dimensions (D) supports vortex stretching that has long been known to accomplish energy transfer to small scales. Moreover, net energy transfer from large-sc…
Nonlinear mode coupling and energetics of driven magnetized shear-flow turbulence
B. Tripathi, A. E. Fraser, P. W. Terry +3
To comprehensively understand saturation of two-dimensional (D) magnetized Kelvin-Helmholtz-instability-driven turbulence, energy transfer analysis is extended from the traditio…
Magnetized fingering convection in stars
Adrian E. Fraser, Sam A. Reifenstein, Pascale Garaud
Fingering convection (also known as thermohaline convection) is a process that drives the vertical transport of chemical elements in regions of stellar radiative zones where the me…
Near-cancellation of up- and down-gradient momentum transport in forced magnetized shear-flow turbulence
B. Tripathi, A. E. Fraser, P. W. Terry +2
Visco-resistive magnetohydrodynamic turbulence, driven by a two-dimensional unstable shear layer that is maintained by an imposed body force, is examined by decomposing it into dis…
Mechanism for Sequestering Magnetic Energy at Large Scales in Shear-Flow Turbulence
B. Tripathi, A. E. Fraser, P. W. Terry +2
Straining of magnetic fields by large-scale shear flow, generally assumed to lead to intensification and generation of small scales, is re-examined in light of the persistent obser…
Magnetized oscillatory double-diffusive convection
Amishi Sanghi, Adrian E Fraser, Edward W Tian +1
We study the properties of oscillatory double-diffusive convection (ODDC) in the presence of a uniform vertical background magnetic field. ODDC takes place in stellar regions that…
Resistive instabilities in sinusoidal shear flows with a streamwise magnetic field
Adrian E. Fraser, Imogen G. Cresswell, Pascale Garaud
We investigate the linear stability of a sinusoidal shear flow with an initially uniform streamwise magnetic field in the framework of incompressible magnetohydrodynamics (MHD) wit…
Characterizing Observed Extra Mixing Trends in Red Giants using the Reduced Density Ratio from Thermohaline Models
Adrian E. Fraser, Meridith Joyce, Evan H. Anders +2
Observations show an almost ubiquitous presence of extra mixing in low-mass upper giant branch stars. The most commonly invoked explanation for this is thermohaline mixing. One-dim…
Schwarzschild and Ledoux are equivalent on evolutionary timescales
Evan H. Anders, Adam S. Jermyn, Daniel Lecoanet +4
Stellar evolution models calculate convective boundaries using either the Schwarzschild or Ledoux criterion, but confusion remains regarding which criterion to use. Here we present…
The impact of magnetic fields on momentum transport and saturation of shear-flow instability by stable modes
A. E. Fraser, P. W. Terry, E. G. Zweibel +2
The Kelvin-Helmholtz (KH) instability of a shear layer with an initially-uniform magnetic field in the direction of flow is studied in the framework of 2D incompressible magnetohyd…
Role of stable modes in driven shear-flow turbulence
A. E. Fraser, M. J. Pueschel, P. W. Terry +1
A linearly unstable, sinusoidal shear flow is examined in the gyrokinetic framework in both the linear and nonlinear regimes. In the linear regime, it is shown that th…
Coupling of Damped and Growing Modes in Unstable Shear Flow
A. E. Fraser, P. W. Terry, E. G. Zweibel +1
Analysis of the saturation of the Kelvin-Helmholtz (KH) instability is undertaken to determine the extent to which the conjugate linearly stable mode plays a role. For a piecewise-…