相关论文: Flow Control with Dynamic Roughness
We introduce a reinforcement learning (RL) environment to design and benchmark control strategies aimed at reducing drag in turbulent fluid flows enclosed in a channel. The environment provides a framework for computationally-efficient,…
The application of drag-control strategies on canonical wall-bounded turbulence, such as periodic channel and zero- or adverse-pressure-gradient boundary layers, raises the question of how to describe control effects consistently for…
Detailed flow dissection using Dynamic Mode Decomposition (DMD) and Proper Orthogonal Decomposition (POD) is carried out to investigate the dynamics of the flow-field around a NACA-0012 aerofoil at a Reynolds number of $5\times 10^4$, Mach…
The fluid dynamics video shows three-dimensional experimental and numerical investigations of open channel flows in microgravity. The dynamic reorientation of the free surface from 1g to 0g environment can be observed in a wedge-shaped…
This study investigates the effect of surface dimples on the unsteady aerodynamics of a National Advisory Committee for Aeronautics airfoil (NACA0012) at a chord-based Reynolds numbers of $Re_c = 5300$ and $10{,}000$ using direct numerical…
The tendency of a jet to stay attached to a flat or convex surface is called the Coand\u{a} effect and has many potential technical applications. The aim of this thesis is to assess how well Computational Fluid Dynamics can capture it. A…
The Karman Vortex Street has been investigated for over a century and offers a reference case for investigation of flow stability and control of high dimensionality, non-linear systems. Active flow control, while of considerable interest…
We briefly discuss an arch-like structure that forms and grows during the rapid straightening of a chain lying on a table. This short note accompanies a fluid dynamics video submission (V029) to the APS DFD Gallery of Fluid Motion 2011.
We experimentally study the nonlinear fluid damping of a rigid but elastically mounted pitching wing in the absence of a freestream flow. The dynamics of the elastic mount are simulated using a cyber-physical system. We perturb the wing and…
In this fluid dynamics video we study the dynamics of miscible vortex rings falling in ambient strongly (near two-layer) stratified fluid. Experiments and direct numerical simulations using the variable density Navier-Stokes (VARDEN) solver…
In recent years, Artificial Neural Networks (ANNs) and Deep Learning have become increasingly popular across a wide range of scientific and technical fields, including Fluid Mechanics. While it will take time to fully grasp the…
Icing on three-dimensional wings causes severe flow separation near stall. Standard improved delayed detached eddy simulation (IDDES) is unable to correctly predict the separating reattaching flow due to its inability to accurately resolve…
Local phonon motion underneath a surface interacting with a flow may cause the flow to passively stabilize, or destabilize, as desired within the region adjacent to the subsurface motion. This mechanism has been extensively analyzed over…
There are numerous devices currently known with the purpose of reducing the irregularity of the flow upstream of the propeller and to decrease by that means the propeller-induced vibration and noise. Many of these devices are wing-shaped…
This article describes the fluid dynamics video: "Turbulent Bubbly Channel Flow: Role of Bubble Deformability." The effect of bubble deformability on the flow rate of bubbly upflow in a turbulent vertical channel is examined using direct…
The self-sustained motion of fluids on gradient substrates is a spectacular phenomenon, which can be employed and controlled in applications by carefully engineering the substrate properties. Here, we report on a design of a gel substrate…
Gaining and understanding the flow dynamics have much importance in a wide range of disciplines, e.g. astrophysics, geophysics, biology, mechanical engineering and biomedical engineering. As a reliable way in practice, especially for…
Kinetic frictional forces resisting droplet motion often appear to be separate to surface wettability and adhesive forces. Here we show that such friction arises from a simple combination of the contact angle hysteresis and adhesive force.…
We study the influence of chain stiffness on droplet flow in a nano-channel, coated with semiflexible hydrophobic polymers by means of non-equilibrium molecular-dynamics simulations. The studied system is then a moving droplet in the slit…
A theoretical model is proposed to explain the roughness characteristics of an ice surface grown from a gravity and wind-driven supercooled water film flowing over an inclined plane. The effects of the water supply rate, plane slope and air…