Presented By: Michigan Institute for Computational Discovery and Engineering
MICDE Ph.D. Student Seminar: Alex Hrabski
Alex Hrabski, PhD Candidate, Naval Architecture & Marine Engineering and Scientific Computing

Topic: Investigations of Wave Turbulence in Bounded Domains
Nonlinear wave systems are ubiquitous in nature, and when many incoherent dispersive waves interact, there is the potential for wave turbulence. Just as in hydrodynamic turbulence (HDT), systems in wave turbulence exhibit inter-scale energy cascades, power-law inertial-range spectra, and even intermittency. Unlike in HDT, however, a natural analytical closure for field statistics has been developed: spectral evolution in wave turbulence can be expressed as a Boltzmann-like kinetic equation. In this talk, we will numerically probe the interplay of nonlinear strength and domain size (critical quantities to the analytical closure) in determining the behaviors of wave turbulence in a model system. Our numerical experiments demonstrate that (a) domain aspect ratio plays a key role in spectral evolution when nonlinearity is weak, (b) that near-resonant interactions are important for the observation of kinetic behavior, and (c) evaluations of the energy cascade can be used to investigate the wave turbulence closure.
Nonlinear wave systems are ubiquitous in nature, and when many incoherent dispersive waves interact, there is the potential for wave turbulence. Just as in hydrodynamic turbulence (HDT), systems in wave turbulence exhibit inter-scale energy cascades, power-law inertial-range spectra, and even intermittency. Unlike in HDT, however, a natural analytical closure for field statistics has been developed: spectral evolution in wave turbulence can be expressed as a Boltzmann-like kinetic equation. In this talk, we will numerically probe the interplay of nonlinear strength and domain size (critical quantities to the analytical closure) in determining the behaviors of wave turbulence in a model system. Our numerical experiments demonstrate that (a) domain aspect ratio plays a key role in spectral evolution when nonlinearity is weak, (b) that near-resonant interactions are important for the observation of kinetic behavior, and (c) evaluations of the energy cascade can be used to investigate the wave turbulence closure.