Reinforcement learning based closed-loop airfoil flow control
3D Direct simulations of flow over wall mounted cylinders
Flow around a finite-height cylinder is ubiquitous in nature and engineering applications such as high-rise buildings, oil storage tanks and colling towers. It is even using as a passive flow control strategy to enhance aerodynamics. The complex vortex shedding structures are multiparemter-defined due to wide range of gometric and flow conditions. We used the direct numerical simulations with modal analysis to investigate the vortical structure variations.
Particle-laden high speed flows
Particle-laden flow occurs in nature, manifesting in phenomena such as volcanic ash clouds resulting from volcanic eruptions, ice crystals, and atmospheric dust, which have been widely observed. The particles suspended in the flow exchange mass, momentum, and energy, forming multiphase flow systems. The impact of high-speed vehicle travels over particle-laden flows were investigated using Lagrangian algorithm overlaid of solution from direct simulation of monte carlo (DSMC).
Wall-particle interaction model
Global stability analysis of flow behind an upswept aftbody
The aftbody's counter-rotating vortex pair affects the maneuverability of the air vehicle and significantly increases drag. We used stability analysis to examine the generation of vortex instability and derive physical insights for suppressing the vortices.
Acoustic response of turbulent cavity
We employ resolvent analysis with Doak's decomposition to investigate the input-output characteristics of vortical, acoustic, and thermal structures in self-sustained cavity flows
Supersonic cavity flow control using resolvent analysis
We designed an active flow control based on the energy amplification mechanism observed in resolvent analysis. The controlled results turned out to be two times more effective than the steady flow control.
Core-pressure alleviation for a wall-normal vortex by active flow control
The core pressure formed under the water pump induces an unstable operational status. The designed active flow control can effectively suppress the generation of the under-pump vortex and has been experimentally validated.
TriGlobal instability analysis over cavity flows
Three-dimensional instability analysis was firstly implemented to examine open cavity flow with lateral walls. The analysis illustrated the three-dimensional shear layer mode.
Instability and sensitivity analysis of flows using OpenFOAM
We implement the direct and adjoint linearized NS solver in to OpenFoam. The new solvers have been tested for various flows.