Research

 

 

Methods

THE IMMERSED INTERFACE METHOD (IIM)

My research on the immersed interface method (IIM) was supported by NSF.

I have been developing the IIM to simulate fluid-solid interactions and two-fluid flows. I have written a few CFD packages for different flow problems.

I am currently writing a CFD package of the IIM to simulate 3D flows with moving complex objects on distributed-memory high performance computers (HPC). Meanwhile I am writing a monograph based on this package to summarize the theory and practice of the IIM.

The key idea of the IIM is to incorporate jump conditions across a fluid-solid or two-fluid interface into a numerical approximation to preserve jump discontinuities in a numerical solution with desired accuracy and high efficiency. An overview of the IIM can be found in IIM4FS&FF.

Below are some of my papers on the IIM organized according to their emphasis.

  • Derivation of jump conditions: 2006 SISC, 2009 DCDS, 2015 JCP

  • Implementation in 2D and 3D: 2006 JCP, 2008 CMAME

  • Boundary condition capturing: 2008 JCP, 2011 JCP

  • Coupling Newtonian dynamics and fluid dynamics: 2012 JFM

  • Particle collisions by lubrication theory: 2018 JCP

  • Two-fluid flows: 2014 NM-TMA

INFLOW TURBULENCE GENERATION

I proposed a recycling-rescaling method to generate inflow turbulence for simulation of spatially evolving compressible turbulent boundary layers. A highlight of this method is its consistent scaling of thermodynamic variables, including means and fluctuations. This method was published in a 2004 PoF paper.

Applications

AERODYNAMICS OF INSECT FLIGHT

We applied the IIM to investigate the wing pitch reversal in insect flight and found that the wing pitch reversal is passive. This work was published in a 2007 JFM paper. I am currently developing 3D CFD models of free flight of insects to study stability, control and maneuverability of insect flight.

TURTULENCE

My research on turbulence included turbulence drag reduction by compliant surfaces and shock-wave-turbulent -boundary-layer interaction.