Yue (Stanley) Ling

• Ph.D.
• Professor at Baylor University

The calculation of the volume enclosed by curved surfaces discretized into triangular elements, and a cube is of great importance in different domains, such as computer graphics and multiphase flow simulations. We propose a robust algorithm, the Front2VOF (F2V) algorithm, to address this problem. The F2V algorithm consists of two main steps. First,...

A series of benchmarks based on the physical situation of “phase inversion” between two immiscible liquids is presented. These benchmarks aim at progressing towards the direct numerical simulation of two-phase flows. Several CFD codes developed in French laboratories and using either Volume-of-Fluid or Level-Set interface tracking methods are used...

The computation of flows with large density contrasts is notoriously difficult. To alleviate the difficulty we consider a discretization of the Navier-Stokes equation that advects mass and momentum in a consistent manner. Incompressible flow with capillary forces is modeled and the discretization is performed on a staggered grid of Marker and Cell...

Paris (PArallel, Robust, Interface Simulator) is a finite volume code for simulations of immiscible multifluid or multiphase flows. It is based on the “one-fluid” formulation of the Navier–Stokes equations where different fluids are treated as one material with variable properties, and surface tension is added as a singular interface force. The flu...

The injection and atomization of gasoline fuels are critical to the performance of gasoline direct injection engines. Due to the complex nature of the primary breakup of the liquid jet in the near field, high-level details are often difficult to measure in experiments. In the present study, detailed numerical simulations are performed to investigat...

The short-term transient falling dynamics of a dripping water drop in quiescent air has been investigated through both simulation and experiment. The focus is on the short term behavior and the time range considered covers about eight dominant second-mode oscillations of the drop after it is formed. Due to the small fluid inertia the growth of the...

The short-term transient falling dynamics of a dripping water drop in quiescent air has been investigated through both simulation and experiment. A representative case with a low inflow rate in the dripping regime is considered. The focus is on the short-term behavior and the time range considered covers about eight dominant second-mode oscillation...

A series of benchmarks based on the physical situation of "phase inversion" between two incompressible liquids is presented. These benchmarks aim at progressing toward the direct numerical simulation of two-phase flows. Several CFD codes developed in French laboratories and using either Volume of Fluid or Level Set interface tracking methods are ut...

Paris (PArallel, Robust, Interface Simulator) is a finite volume code for simulations of immiscible multi fluid or multiphase flows. It is based on the “one-fluid” formulation of the Navier-Stokes equations where different fluids are treated as one material with variable properties, and surface tension is added as a singular interface force. The fl...

The two-phase mixing layer formed between parallel gas and liquid streams is an important fundamental problem in turbulent multiphase flows. The problem is relevant to many industrial applications and natural phenomena, such as air-blast atomizers in fuel injection systems and breaking waves in the ocean. The velocity difference between the gas and...

The computation of flows with large density contrasts is notoriously difficult. To alleviate the difficulty we consider a consistent mass and momentum-conserving discretization of the Navier-Stokes equation. Incompressible flow with capillary forces is modelled and the discretization is performed on a staggered grid of Marker and Cell type. The Vol...

A spherical blast wave generated by a sudden release of a sphere of compressed gas is an important model problem to understand blast phenomena such as volcanic eruptions and explosive detonations. The resulting explosion flow physics, such as the instability at the gas contact discontinuity and the interaction between the shock wave and the gas con...

The two-phase mixing layer formed between parallel gas and liquid streams is an important fundamental problem in turbulent multiphase flows. The problem is relevant to many industrial applications and natural phenomena, such as air-blast atomizers in fuel injection systems and breaking waves in the ocean. The velocity difference between the gas and...

A spherical particle-laden blast wave, generated by a sudden release of a sphere of compressed gas–particle mixture, is investigated by numerical simulation. The present problem is a multiphase extension of the classic finite-source spherical blast-wave problem. The gas–particle flow can be fully determined by the initial radius of the spherical mi...

Under shock loading, metals have been found to melt and with reflection of the shock wave from the material free surface, cavities nucleate and grow. This process is referred to as micro spall and has been studied experimentally with analytical models describing debris sizes. Measurements during the cavity growth phase are not possible at present a...

Under shock loading, metals have been found to melt and with reflection of the shock wave from the material free surface, cavities nucleate and grow. This process is referred to as micro spall and has been studied experimentally with analytical models describing debris sizes. Measurements during the cavity growth phase are not possible at present a...

The utilization of biodiesel is an effective approach to reduce pollution from internal combustion engines and thushas attracted steadily increasing interest in the recent years. As the viscosity of biodiesel is much higher than that of standard diesel, the atomization characteristics of a biodiesel jet can significantly deviate from those of a sta...

The three-dimensional development of instabilities and the subsequent spray formation in a gas-liquid mixing layer are important fundamental problems in the area of multiphase flows. It is highly desirable to visualize this detailed atomization process and to analyze the instabilities and mechanisms involved, and massive numerical simulations are r...

Droplet migration in a Hele–Shaw cell is a fundamental multiphase flow problem which is crucial for many microfluidics applications. We focus on the regime at low capillary number and three-dimensional direct numerical simulations are performed to investigate the problem. In order to reduce the computational cost, an adaptive mesh is employed and h...

The present paper addresses important fundamental issues of inter-phase heat transfer and energy coupling in turbulent dispersed multiphase flows through scaling analysis. In typical point-particle or two-fluid approaches, the fluid motion and convective heat transfer at the particle scale are not resolved and the momentum and energy coupling betwe...

We present a study of droplet formation in a gas-liquid mixing layer using direct numerical simulation. It is seen that two mechanisms compete to generate the droplets: fingering at the tip of the waves and hole formation in the thin liquid sheet. The three dimensional liquid structures are much shorter than the longitudinal wavelength of the insta...

Droplet-based microfluidics is a promising tool for performing biochemical or chemical assays. Droplets are unit systems of controlled volume and content, within which mixing, reacting and/or transferring can be achieved. Therefore, a comprehensive understanding of droplet migration in confined microchannels is essential to many microfluidics appli...

Modeling and simulation of atomization is challenging due to the existence of a wide range of length scales. This multiscale nature of atomization introduces a fundamental challenge to numerical simulation. A pathway to comprehensive modeling is still to be found. The present study proposes a multiscale multiphase flow model for atomization simulat...

We propose a numerical approach to study the mechanics of a flowing bubble in a constraint micro channel. Using an open source two phase flow solver (Gerris, gfs.sourceforge.net) we compute solutions of the bubble dynamics (i.e. shape and terminal velocity) induced by the interaction between the bubble movement, the Laplace pressure variation, and...

We are interested in the phase separation of a light fluid in a heavier fluid in a closed box. A simple initial configuration is considered. A cubic volume of light fluid with a characteristic length H/2 is contained in the bottom part of a cubic box of side H filled with a heavier fluid. This problem is typical of multiscale interfacial flows in w...

The nonlinear growth of instabilities of an outward propagating, but decelerating, cylindrical interface separated by fluids of different densities is investigated. Single mode perturbations are introduced around the contact-surface, and their evolution is studied by conducting inviscid 2D and 3D numerical simulations. In the past, a significant am...

Accurate momentum coupling model is vital to simulation of dispersed multiphase flows. The overall force exerted on a particle is divided into four physically meaningful contributions, i.e., quasi-steady, stress-gradient, added-mass, and viscous-unsteady (history) forces. Time scale analysis on the turbulent multiphase flow and the viscous-unsteady...

The interaction of shock waves with deformable particles is an important fundamental problem. In some applications, e.g., the detonation of explosives loaded with metal particles, the pressure behind the shock wave can be significantly larger than the yield strength of the particle material. This means that particles can deform severely during thei...

The interaction of a planar shock wave with a dense particle curtain is investigated through modeling and experiments. The physics in the interaction between a shock wave with a dense gas-particle mixture is markedly differently from that with a dilute mixture. Following the passage of the shock wave, the dense particle curtain expands rapidly as i...

Particle dispersal by blast waves is an interesting phenomenon. A model problem, i.e., a sudden release of a compressed gas–particle mixture contained in a spherical container, is employed to investigate the fundamental physics of particle dispersal. The problem is simulated by the multiphase flow models proposed in Part 1 of this article that incl...

Shock–particle interaction is an important phenomenon. The interaction can be accurately resolved by direct numerical simulations. However, as the length scales of interest are much larger than the particle size in many applications, fully resolving the flow around the particle is impractical. Therefore, rigorous model for momentum and energy excha...

Modern energetic materials have embedded solids and inerts in an explosive matrix. A detonation in condensed phase materials, generates intense shocks that deform particles as the incident shock diffracts around them. The post-shock flow generates a wake behind the particle that is influenced by the shape changes of the particle. The gasdynamic flo...

Particle dispersal by shock/detonation waves is a challenging problem due to the complex interactions between the particles and the compressible flow features that must be captured rigorously in modeling and simulations. Previous experiments and direct numerical simulations have shown that the particle force and heating can be much larger than thos...

Particle interaction with shock/detonation waves is a fundamental phenomenon. In many practical applications, shock/detonation waves interact with a very large number of particles and the scales of interest are typically much larger than particle size. Therefore, fully resolving the flow around all the particles is impractical. Therefore, rigorous...

When a highly compressed gas-particle mixture is suddenly released, the particles will be dispersed outward in very high speed driven by the rapid expanding gas. This is a phenomenon which can be observed in nature, such as volcanic eruption, and many industrial applications, such as detonation of multiphase explosives. The unsteady compressible na...

Eulerian–Lagrangian simulations of multiphase flow are known to suffer from two errors that can introduce small-scale fluctuations in the number-density of the dispersed phase. These errors can be reduced by increasing the number of particles in the simulation. Here, we present results to demonstrate that a third error exists that can also generate...

An unsteady compressible multiphase flow model is proposed in the present study to solve the extended problem of Brode (Brode, H. L., "Numerical Solutions of Spherical Blast Waves," J. Appl. Phys., Vol. 26, 1955, pp. 766-775), namely an explosion generated by a spherical charge containing a compressed gas-particle mixture. One-way coupled simulatio...

The transient behavior of compressible gas– particle flows produced in shock tubes with particle-laden driver section is studied. Particular attention is focused on the time scales with which the solution approaches the equilibrium state. Theoretical estimates indicate that the gas and particle contact surfaces equilibrate first, followed by the sh...

Some effects of a detonating particle-laden explosive can be modeled through the explosion of a compressed gas-particle suspension. The suspension can be considered to be located in a spherical container and released through the instantaneous removal of the container similar to a shock tube. The transient flow generated by the removal of the contai...

The interaction between shock waves and particles is studied numerically using an Eulerian approach for the gas and a Lagrangian approach for the particles. Two examples of shock waves interacting with particles are studied. In the first, the interaction of a shock wave with a gas-particle interface and its subsequent deceleration to equilibrium co...