Turbulence and Multiphase Flows
Nonlocal energy transfers in rotating turbulence at intermediate Rossby number 
Turbulent flows subject to solidbody rotation are known to generate steep energy spectra and twodimensional columnar vortices. The localness of the dominant energy transfers responsible for the accumulation of the energy in the twodimensional columnar vortices of large horizontal scale remains undetermined. Here, we investigate the scalelocality of the energy transfers directly contributing to the growth of the twodimensional columnar structures observed in the intermediate Rossby number (Ro) regime. Our approach is to investigate the dynamics of the waves and vortices separately: we... more 

Nonlocal interactions and condensation in forced rotating turbulence 
The Rossby number, Ro=U/L2Ω, is the nondimensional number characterizing rotating flows. Here U is the characteristic velocity, L the characteristic length scale, and 2Ω is the Coriolis parameter. When Ro → 0 the nonlinearity of the equations of motion becomes weak, and the theories of weak wave interactions apply. The normal modes of the flow can be decomposed... more 

Quantification of the discretization effects in the representation of key inertialwave interactions in rotating turbulence 
The NavierStokes equations in a rotating frame lead to solutions characterized by interactions between wave modes. In asymptotic and weakturbulence theories, resonant and nearresonant interactions between those modes are expected to be dominant. It is imperative to sufficiently resolve the near resonant interactions that are thought to be important in the strong rotation limit. When rotating turbulence is studied in a finitesize domain, discrete effects are introduced. We investigate the discretization effects on the capture of exact and nearresonant interactions by numerical... more 

Discreteness and resolution effects in rapidly rotating turbulence 
Rotating turbulence is characterized by the nondimensional Rossby number Ro, which is a measure of the strength of the Coriolis term relative to that of the nonlinear term. For rapid rotation (Ro→0), nonlinear interactions between inertial waves are weak, and the theoretical approaches used for other weak (wave) turbulence problems can be applied. The important interactions in rotating turbulence at small Ro become those between modes satisfying the resonant and nearresonant conditions. Often, discussions comparing theoretical results and numerical simulations are questioned because of a... more 

Model of truncated fast rotating flow at infinite Reynolds number 
The purpose of this study is to examine the strongly rotating limit of a turbulent flow theoretically and numerically. The goal is to verify the predictions of asymptotic theories. Given the limitations of experimental and dissipative numerical approaches to this problem, we use classical equilibrium statistical mechanics. We apply the statistical mechanics approach to the inviscid truncated model of strongly rotating turbulence in the small Rossby number range and derive the theoretical spectra of the decoupled model. We use numerical simulations to complement these derivations and... more 

IntermediateRossbynumber range in rotating homogeneous turbulence 
Rotating homogeneous turbulence in a finite domain is studied using numerical simulations, with a particular emphasis on the interactions between the wave and zerofrequency modes. Numerical simulations of decaying homogeneous turbulence subject to a wide range of background rotation rates are presented. The effect of rotation is examined in two finite periodic domains in order to test the effect of the size of the computational domain on the results obtained, thereby testing the accurate sampling of nearresonant interactions. We observe a nonmonotonic tendency when Rossby number Ro is... more 

Violent Expirations: importance of the turbulent multiphase flow 
Violent respiratory events such as coughs and sneezes play a key role in transferring respiratory diseases between infectious and susceptible individuals. We present the results of a combined experimental and theoretical investigation of the fluid dynamics of such violent expiratory events. Direct observation of sneezing and coughing events reveals that such flows are multiphase turbulent buoyant clouds with suspended droplets of various sizes. Our observations guide the development of an accompanying theoretical model of pathogenbearing droplets interacting with a turbulent buoyant... more 