Published in Journal of Hydrodynamics
In view of the long stagnation in traditional turbulence modeling, researchers have attempted using machine learning to augment turbulence models. This paper presents some of the recent progresses in our group on augmenting turbulence models with physics-informed machine learning. We also discuss our works on ensemble-based field inversion to provi...
Published in Journal of Hydrodynamics
Kolmogorov’s 1941 theory (K41) of similarity hypotheses and the −5/3 law for energy spectrum are considered as the most important theoretical achievement in turbulence research and the success of the modern turbulence theory. The assumptions of sufficient high Reynolds number and isotropy of turbulence that K41 based upon, however, cannot generally...
Published in Journal of Hydrodynamics
This paper presents the development of a theoretical model of fully nonlinear and weakly dispersive (FNWD) waves and numerical techniques for simulating the propagation, interaction, and transformation of solitary waves. Using the standard expansion method and without the limit of small nonlinear parameter defined as the ratio of the wave height ve...
Published in Journal of Hydrodynamics
The fundamental solutions of the Stokes/Oseen equations due to a point force in an unbounded viscous fluid are referred to as the Stokeslet/Oseenlet, for which a systematic derivation are analytically presented here in terms of a uniform expression. By means of integral transforms, the closed-form solutions are explicitly deduced in a formula which...
Published in Journal of Hydrodynamics
An account of my interactions with Prof. Theodore Yao-tsu Wu of the California Institute of Technology.
Published in Journal of Hydrodynamics
We present a machine learning based method for RANS modeling in the rotating frame of reference (RFR). The extended intrinsic mean spin tensor (EIMST) is adopted in a novel expansion of the evolution algorithm, named multi-dimensional gene expression programming (MGEP). Based on DNS data, a constrain free model for Reynolds stress is created by con...
Published in Journal of Hydrodynamics
In this paper, an explicit low-storage simplified M — stage Runge-Kutta (SRK) scheme for high Reynolds-number incompressible flows is presented. In the SRK scheme, the Poisson equation is solved only once in the final substage of each time step. By taking advantage of the SRK scheme and the advanced hybrid MPI+MPI model, we have developed an effici...
Published in Journal of Hydrodynamics
We consider strongly nonlinear long waves on the surface of a homogeneous fluid layer. By modifying the formulation for the high-order spectral (HOS) method for waves in water of finite depth, we present a higher-order nonlinear system for the surface elevation and the velocity potential on the free surface to describe the two-dimensional evolution...
Published in Journal of Hydrodynamics
Tip vortex cavitation (TVC) is an important cavitation phenomenon in marine propeller. The formation and evolution of tip vortex cavitation are hot topics consistently both in engineering application and mechanism research. In this paper some recent studies on tip vortex cavitation inception and the noise of tip vortex cavitation evolution are pres...
Published in Journal of Hydrodynamics
The vortex core detection method based on the Liutex vector is utilized to investigate the alternation of vortical structures on a boundary layer transition subjected to spanwise-wall oscillation. Compared with iso-surface based methods, the Liutex core line method is shown to be precise, free of threshold and capable to capture both strong and wea...
