流体动力学
A new arbitrary Lagrangian-Eulerian (ALE) formulation for Navier-Stokes flow on self-evolving surfaces is presented. It is based on a general curvilinear surface parameterization that describes the motion of the ALE frame. Its in-plane part…
Elasto-inertial turbulence (EIT) has been demonstrated to be able to sustain in two-dimensional (2D) channel flow; however the systematic investigations on 2D EIT remain scare. This study addresses this gap by examining the statistical…
An analytical theory is presented for linear, local, short-wavelength instabilities in swirling flows, in which axial shear, differential rotation, radial thermal stratification, viscosity, and thermal diffusivity are all taken into…
We study the stationary, intermittent, and nonlinear dynamics of natural and forced supersonic twin-rectangular turbulent jets using spectral modal decomposition. We decompose large-eddy simulation data into four reflectional symmetry…
This study investigates the onset of linear instabilities and their later nonlinear interactions in the shear layer of an initially-laminar jet using a combination of stability analysis and data from high-fidelity flow simulations. We…
We report the presence of traveling Elastic Waves in experiments featuring a shear flow in the very low Reynolds number regime (Re < 0.1) with no external curvatures or internal perturbations in the channel design. The classic…
High-pressure combustion is central to modern propulsion and power-generation systems, where operating pressures often exceed the critical point of working fluids, resulting in pronounced real-fluid effects that fundamentally alter…
This study investigates the dynamics of Strato-Rotational Instability (SRI) in a stratified, rotating fluid, focusing on the interaction between axial modes and spiral components. Through numerical analysis, we find that SRI induces…
We propose an unsplit scheme for interface advection in a novel Front-Tracking method, called the Edge-Based Interface Tracking (EBIT) method. In the EBIT method, the markers are placed on the grid edges, and their connectivity is…
We report three stages for locomotion of a helical swimmer in yield stress fluids. In the first stage, the swimmer must overcome material's yield strain to generate rotational motion. However, exceeding the first threshold is not sufficient…
We investigate the linear onset of thermal convection in rotating spherical shells with a focus on the influence of mechanical boundary conditions and thermal driving modes. Using a spectral method, we determine critical Rayleigh numbers,…
This study develops and validates neural network frameworks with physics-based constraints for surrogate modeling of rarefied gas dynamics across different levels of complexity. As a baseline, we first examine the BGK kinetic relaxation…
This study experimentally investigates bubble size evolution and void fraction redistribution in an unexplored, coalescence-dominated regime of decaying turbulent bubbly flow. The flow is generated downstream of a regenerative pump in a…
When developing scientific machine learning (ML) approaches, it is often beneficial to embed knowledge of the physical system in question into the training process. One way to achieve this is by leveraging the specific characteristics of…
An experimental framework was developed to study the initiation of particle mobilization in a laboratory setting. Large and heavy particles mobilized by a turbulent, gaseous carrier-phase were considered. An airfoil oscillated in the…
We study two-dimensional turbulence in a square no-slip domain without bottom drag using direct numerical simulations. The dynamics are shown to depend strongly on the torque $M$ of the external forcing. When $M$ is relatively large, a…
Sea ice is a key component of the Earth's climate system, making its aging process an essential focus of current research. The age of sea ice is closely linked to its thermal and mechanical properties, which govern its interactions with the…
When a floating body is internally or externally vibrated, its self-generated wavefield can lead to steady propulsion along the interface. In this article, we review several related and recently discovered systems that leverage this…
Turbulence generation mechanisms in stratified, rotating flows past three-dimensional (3D) topography remain underexplored, particularly in submesoscale (SMS) regimes critical to geophysical applications. Using turbulence-resolving…
We present the optimal hydrodynamic model for rarefied gas flows relative to a given kinetic model by combining the recent theory of slow spectral closure with machine learning techniques. We learn generalized transport coefficients from…