Qing He Yao

Sun Yat-Sen University | SYSU · Department of Applied Mechanics and Engineering

This paper is devoted to the global well-posedness and the optimal time decay rates for the two-dimensional compressible Oldroyd-B model. By introducing new quantities, we find another better perturbation system to eliminate the cross linear terms easily and build the global well-posedness of the strong solution with small initial data in \(H^2({\m...

Aiming at the long-term and high-precision simulation of the magnetohydrodynamic (MHD) instabilities in the tokamak model, we developed a parallelized solver based on a fully implicit difference scheme. A 4th-order precision difference scheme and the Newton–Krylov method are employed in the proposed solver for both the flow and the electromagnetic...

In this paper, we consider the optimal time decay rates of the higher order spatial derivatives of global solution for the three-dimensional compressible Oldroyd-B model, which was derived independently by Barrett-Lu-Süli [Commun. Math. Sci., 15(5): 1265–1323, 2017] via micro–macro analysis of the compressible Navier–Stokes–Fokker–Planck system. We...

This paper focuses on the vanishing limit problem for the three-dimensional incompressible Phan-Thien–Tanner (PTT) system, which is commonly used to describe the dynamic properties of polymeric fluids. Our purpose is to show the relation of the PTT system to the well-known Oldroyd-B system (with or without damping mechanism). The suitable a priori...

The consumption of solving large-scale linear equations is one of the most critical issues in numerical computation. An innovative method is introduced in this study to solve linear equations based on deep neural networks. To achieve a high accuracy, we employ the residual network architecture and the correction iteration inspired by the classic it...

In this work, we construct a data-driven model to address the computing performance problem of the moving particle semi-implicit method by combining the physics intuition of the method with a machine-learning algorithm. A fully connected artificial neural network is implemented to solve the pressure Poisson equation, which is reformulated as a regr...

The pressure Poisson equationis usually the most time-consuming problem in fluid simulation. To accelerate its solving process, we propose a deep neural network-based numerical method, termed Deep Residual Iteration Method (DRIM), in this paper. Firstly, the global equation is decomposed into multiple independent tridiagonal sub-equations, and DRIM...

Aiming at the long-term and high-precision simulation of the magnetohydrodynamic (MHD) instabilities in the tokamak model, we developed a parallelized solver based on a fully implicit difference scheme. A 4th-order precision difference scheme and the Newton-Krylov method are employed in the proposed solver for both the flow and the electromagnetic...

Thermal design and management is important to improve the CO2 capture by adsorption's efficiency, but current studies only consider geometric designs of a specific size. This paper develops a 2D multi-physics model to study how the spacing between two fluid pipes in the adsorbent bed affects the desorption performance, which couples the species tra...

λ A DNN-based algorithm that solves the multi-diagonal linear equations is proposed. λ We employed an iteration method that decreased the error of the numerical solution to 10− 7. λ The computational efficiency of the proposed method is 2 to 10 times of the classic algorithms.

This research addresses the global Mittag-Leffler stability and synchronization control problems of the fractional-order memristor-based neural network, which more accurately describes physical phenomena than integer-order networks system, and simultaneously exhibits complex dynamic behaviors. Specifically, the difficulties due to the processing of...

In this paper, we investigate the large-time behavior of strong solutions to the Cauchy problem for one-dimensional compressible isentropic magnetohydrodynamic equations near a stable equilibrium. The difference between the one-dimensional and multi-dimensional cases is a feature for compressible flows and also brings new difficulties. In contrast...

Our focus in this paper is to investigate the sharp time decay rates (upper and lower bounds) for the higher order spatial derivatives of large solutions to the magnetohydrodynamic (MHD) flow of an incompressible Phan-Thien-Tanner (PTT) fluid. In dimension two, the sharp time decay rates of large solution (u,H) and all its derivatives have been sho...

In this paper, we consider the magnetohydrodynamic (MHD) flow of an incompressible Phan-Thien–Tanner (PTT) fluid in two space dimensions. We focus upon the sharp time decay rates (upper and lower bounds) and global-in-time stability of large strong solutions for the PTT system with magnetic field. Firstly, the convergence of large solutions to the...

PurposeWe have been developing a new type of miniscrew to specifically withstand orthodontic torque load. This study aimed to investigate the effect of thread depth and thread pitch on the primary stability of these miniscrews if stressed with torque load.Methods Finite element analysis (FEA) was used to evaluate the primary stability of the minisc...

Carotid stenosis is a common physiological abnormality that can cause a stroke or even death. For a clear understanding of its forming mechanism and potential damage, a hemodynamics model of carotid artery stenosis in a swine is built and analyzed based on surgery and ultrasonography. Eight Chinese mini-swine were partially ligated; transcranial Do...

Cellular neural networks with D operator and time-varying delays are found to be effective in demonstrating complex dynamic behaviors. The stability analysis of the pseudo-almost periodic solution for a novel neural network of this kind is considered in this work. A generalized class neural networks model, combining cellular neural networks and the...

A new Generalized Phan–Thien–Tanner (GPTT) model is derived from a Lodge–Yamamoto type of network theory for the polymeric fluids. The GPTT model is developed to describe the rheological behavior of the viscoelastic fluids. In this paper, we investigate the initial-value problem for the GPTT model. Under the norm of the initial data is a small pert...

In recent years, artificial neural networks (ANNs), especially deep neural networks (DNNs), have become a promising new approach in the field of numerical computation due to their high computational efficiency on heterogeneous platforms and their ability to fit high-dimensional complex systems. In the process of numerically solving the partial diff...

Lattice Boltzmann Method（LBM）is a kind of widely used mesoscopic fluid numerical simulation method. The drawback of LBM is the high computational cost，which causes difficulties in real-time simulation. In this work，we created a Convolutional Neural Network（CNN）based on U-Net to accelerate LBM calculation. The purpose is to replace multiple LBM step...

As a mesoscopic approach, the lattice Boltzmann method has achieved considerable success in simulating fluid flows and associated transport phenomena. The calculation, however, suffers from a massive amount of computing resources. A predictive model, to reduce the computing cost and accelerate the calculations, is proposed in this work. By employin...

Oscillatory flow has many applications in micro-scaled devices. The methods of realizing microfluidic oscillators reported so far are typically based on the impinging-jet and Coanda effect, which usually require the flow Reynolds number to be at least at the order of unity. Another approach is to introduce elastomeric membrane into the microfluidic...

Quaternion-valued inertial memristor-based neural networks with time-varying delays are found to be effective in demonstrating complex dynamic behaviors. Considering the stability of the periodic solution for a novel neural network, we construct a class quaternion-valued inertial memristor-based neural network model by combining with the cellular n...

This paper proposes to utilize the waste heat of a solar-driven Organic Rankine cycle (ORC) to support the regeneration process of the carbon capture by adsorption (CCA) subsystem. The waste heat is utilized in cascaded form, where the higher temperature component is supplied to the CCA device, and the lower temperature component is internally exch...

Simulation method for water injection (WI) combustion of hydrogen engine was applied in this paper, to study the effect of WI on engine operation. AVL-FIRE software was used to simulate the combustion conditions of JH-600 engine using hydrogen fuel, the temperature, pressure, NO emission and other parameters of the cylinder are simulated during thi...

In this paper，a parallel solving algorithm for the MHD equations based on the toroidal tokamak model is proposed，and the algorithm focuses on the numerical simulation of the nonideal MHD instability and its development process. In the proposed algorithm，we selected a fully-implicit scheme in the discretization，which has less limited time steps than...

Compared to the traditional computational fluid dynamics techniques，the Lattice Boltzmann Method（LBM）has the advantages of simple structure of program，strong adaptability to complex boundaries as well as nonlinear problems，and high parallelism. However，since LBM is an explicit algorithm，its calculation usually involves many iteration steps，and ther...

A coupled analysis of agent behavior and Computational Fluid Dynamics (CFD) model is applied to investigate the fire evacuation effectiveness in a popular metro station in Guangzhou, China. Due to the high density and complexity of traffic, the concept of Required Safe Escape Time and Available Safe Escape Time (RSET/ASET), which is more flexible a...

Fuel cell hybridization with different energy devices is recently a highly effective method to improve the fuel cell performance for supplying power and heat, and even allow for supplying cooling energy and water. This review article performs a comprehensive review of hybridizing the fuel cell to a wide range of other energy devices and conducts a...

In this paper, the seepage finite element method (FEM) is used to simulate the transient seepage of Beijiang Dike, and antiseepage solutions are designed and discussed. By comparing the measured data of a piezometer with the steady-state calculation model, the calculated results are compatible very well with the measured data. Aiming to improve the...

This study aimed to investigate the effect of miniscrews thread shape on the stress distribution receiving a torque load. Seven thread shapes (S,V1,V2,B1,B2,R1,R2) models were constructed and a 6 Nmm-torque load was applied. The order of maximum equivalent stress (EQV) value was V1 > V2 > B1 > R1 > R2 > B2 > S. The order of maximum displacement of...

Despite the enhanced energy savings offered by a fuel cell micro combined heat and power system for buildings, this system has several technical issues such as a large mismatch in the power/heat supply to demand ratio and high capital costs. This paper proposes to use the thermoelectric heater to enhance the fuel cell micro combined heat and power...

This paper presents a three-dimensional finite element analysis that couples the high temperature proton exchange membrane fuel cell (HT-PEMFC) and thermoelectric generator into a single model. The proposed model is aimed to accurately simulate this hybrid system by implementing the laminar one-phase flow, concentrated species, ideal gas law physic...

Although the thermoelectric device (TED) has recently been studied as a sub-cooler of the trans-critical CO2 cycle, setting the TED to uniquely be an internal heat exchanger (i.e. TED-IHX) is an implementation that is yet to be well studied. Therefore, this paper’s objective is to study the potential of integrating the TED – internal heat exchanger...

Previously, the combined thermoelectric generator and cooler (TEG-TEC) control technique was proposed for thermal management of devices, where the TEG mode is used for energy harvesting and the TEC mode is used for active temperature control. This research significantly improves the TEG-TEC control technique by including the components that ensure...

Although integrating the thermoelectric device (TED) to fuel cells (FC) is a promising way to improve the overall system's output efficiency, its application to the micro-combined heat and power (μCHP) application requires an effective energy management strategy. Therefore, this paper aims to develop a real time energy management strategy (EMS) tha...

Although the integration of heat pumps with fuel cells for micro combined heat and power is a viable solution for reducing hydrogen energy consumption, recent studies have typically only considered the vapour compression cycle as the selected heat pump. This research proposes a multi-objective optimisation methodology to analyse the performance of...

In China, Platycladus orientalis has a lifespan of thousands of years. The long lifespan of these trees may be relevant for the characterization of plant aging at the molecular level. However, the molecular mechanism of the aging process of P. orientalis is still unknown. To explore the relationship between age and growth of P. orientalis, we analy...

Variation in species composition between two communities is so-called β diversity, or dissimilarity, and can be separated into two components: turnover and nestedness. However, the mechanisms underlying these two components remain ambiguous, particularly for different lifeforms. In this study, we examined the altitudinal gradient of biodiversity in...

Although the Peltier sub-cooled trans-critical CO 2 cycle concept has been applied for refrigeration, which typically involves discharging the heat into ambient air, this system is rarely considered for heat pumping purposes. Therefore, this research aims to expand the scope of the Peltier sub-cooled trans-critical CO 2 cycle into heat pump water h...

To investigate the flow regularity of smoke in the subway station, Fire Dynamics Simulator is used to simulate the fire smoke spread in the Higher Education Mega Center North Station in this paper. In this paper, the boundary conditions required for numerical simulation are determined based on the measured temperature and air velocity in the subway...

Fuel cell based combined heat and power systems (FC-CHP) are a promising technology which can provide efficiently both electrical power and heat to residential and industrial consumers. However, FC-CHP system are typically complex in nature where much of the complexity arises from the necessary subsystems to operate the FC itself. This paper propos...

This research conducts a thermodynamic and transient analysis of the hybrid concentrated photovoltaic panel and vapour compression cycle thermal (CPV-VCC/T) system that is designed for combined heat and power purposes. The model includes both the VCC's thermodynamic model and the evaporator (CPV side) heat exchanger's convective heat transfer effec...

In this study, a coupled program of an agent-based evacuation model and a Computational Fluid Dynamics (CFD) model is applied to investigate the fire evacuation in a typical side platform of a metro station in Guangzhou, China. More adaptable to various fire scenarios than the "6 minutes" principle widely used in China, the concept of Required Safe...

In this study, a coupled program of an agent-based evacuation model and a Computational Fluid Dynamics (CFD) model is applied to investigate the fire evacuation in a typical side platform of a metro station in Guangzhou, China. More adaptable to various fire scenarios than the "6 minutes" principle widely used in China, the concept of Required Safe...

Many domestic and overseas scholars have researched smoke dispersion, smoke field and temperature field. However, the research on emergency escape seems to be lacking. This paper simulates the density field and air distribution of some fire behavior using CFD methods and analyzes the corresponding effects of fire location and exhaust smoke level. T...

While the integration of the fuel cell (FC) and the semiconductor thermoelectric device (TED) to form a clean energy hybrid FC-TED system has been previously studied using 0-D mathematical equations, a 3-D finite element model that couples together the physics between the two devices is yet to be comprehensively studied. This paper introduces a 3-D...

Although implementations of CPVs to support electrolysis to produce hydrogen have recently been established, they often neglect the heat component which is important to improve electrolysis efficiency. Therefore, this research proposes to integrate the vapor compression cycle to concentrated photovoltaic panels to form a combined heat and power sys...

Although FC based electric buses are currently popular on urban streets or in short transit routes within large facilities, the version that is designed to operate on a highway, which has much higher dynamic requirements, is yet to be well developed. This research proposes to adopt the NSGA-II based multi-objective optimization scheme to optimize a...

Optimization of an air conditioning system is critical in terms of the transient and steady state behavior of the air distribution along the room and the temperature of the equipment themselves. In this paper, three computational techniques, namely, the standard k-ε , RNG k-ε , and the k-ω model, are used to numerically simulate and determine the a...

The combined heat and power system is a highly efficient energy source for many applications because heat and power are often of high demand. Although fuel cells and thermoelectric generators are popularly known to be used separately for combined heat and power purposes, there is little research on combining these two components for this applicatio...

The design of the refrigeration system is an important part of the optimization management of the computer center, which also has a direct impact on the stable operation of the internal equipment. In this paper indoor temperature was measured with the traditional measurement method, and the fluid field and temperature field were simulated by comput...

In this work, the computational fluid dynamics (CFD) method is used to study the resistance character of an underwater vehicle in a specific undersea tunnel circumstance. In order to prove the validity of the proposed method, the standard Suboff model was numerically calculated and the simulation results were in agreement with the experimental data...

Simulated by sFlow 1.1 (in-house version). Post-processed by MicroAVS.

A hemodynamics analysis approach based on the domain decomposition for medical imaging processing and the characteristic curve for flow simulation with patient-specific cerebral vasculature geometry is presented. The flow solver is validated by comparison with some benchmarks in previous work and is then applied to investigate blood flow in actual...

A parallel computation is applied to study the flow past a pair of cylinders in tandem at Reynolds numbers of 1000 by Domain Decomposition Method. The computations were carried out for different sets of arrangements at large scale. The modeling by domain decomposition was validated by comparing available well-recognized results. Two cylinders with...

The dispersion behaviour of leaking hydrogen in a partially open space is simulated numerically by a stabilized finite element approximation in domain decomposition system in this work. An analogy of the thermal convection problems is applied. The linear systems of Navier-Stokes equations and the convection diffusion equation are symmetrized by a p...

In order to enhance the robustness of visual tracking algorithm in complex environment, a novel visual tracking algorithm based on multifeature selection and sparse representation is proposed. In the framework of particles filter, particles with low target similarity are first filtered out by a fast algorithm; then, based on the principle of sparse...

The dispersion behaviour of leaking hydrogen in a partially open space is simulated numerically by a balancing domain decomposition method in this work. An analogy of the thermal convection problems is applied. The linear systems of Navier–Stokes equations and the convection diffusion equation are symmetrized by a pressure stabilized domain decompo...

A backward-facing step flow in the microchannel with external electric field was investigated numerically by a high-order accuracy upwind compact difference scheme in this work. The Poisson-Boltzmann and Navier-Stokes equations were computed by the high-order scheme, and the results confirmed the ability of the new solver in simulation of micro-sca...

The invention discloses a data parallel treatment based virtual reality 3D simulation method and system. The method comprises the steps of: establishing a three-dimensional model and setting initial border conditions; performing domain decomposition on the three-dimensional model; inputting the initial border conditions and element information in e...

In order to determine the position and orientation of an object in the wrist frame for robot, transform relation of hand-eye system should be estimated, which is described as rotational matrix and translational vector. A new approach integrating neural network and particle swarm optimization algorithm with crossover and mutation operation for robot...

The purpose of this study was to investigate the spray dried lactose as carrier for dry powder inhalation (DPI). The lactose particles were prepared by spray drying, then the particle size, shape and crystal form were characterized by laser diffraction, scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetr...

The dispersion behaviour of leaking hydrogen in a partially open space is simulated by a balancing domain decomposition method in this work. An analogy of the Boussinesq approximation is employed to describe the connection between the flow field and the concentration field. The linear systems of Navier-Stokes equations and the convection diffusion...

Abstract Novel granulated pellets technique was adopted to prepare granulated pellet-containing tablets (GPCT). GPCT and traditional pellet-containing tablets (PCT) were prepared according to 29 formulations devised by the Design Expert 7.0, with doxycycline hydrochloride as model drug, blends of Eudragit FS 30D and Eudragit L 30D-55 as coating mat...

A parallel characteristic curve method is applied in domain decomposition system to simulate the dispersion behavior of hydrogen in this work. The characteristic curve method is employed to approximate the Navier-Stokes equations and the convection diffusion equation, and the feasibility of solving complex multicomponent flow problems is demonstrat...

The invention relates to a simulation method and a stimulation system used for online detection of hydrogen leakage. The method comprises the steps of: detecting hydrogen storage and hydrogen concentration around a transmitting device in real time; when the hydrogen concentration detected is more than the set threshold value, determining the size a...

A pressure-stabilized Lagrange-Galerkin method is implemented in a parallel domain decomposition system in this work, and the new stabilization strategy is proved to be effective for large Reynolds number and Rayleigh number simulations. The symmetry of the stiffness matrix enables the interface problems of the linear system to be solved by the pre...

The motions of the airflow induced by the movement of an automatic guided vehicle (AGV) in a cleanroom are numerically studied by large-scale simulation. For this purpose, numerical experiments scheme based on domain decomposition method is designed. Compared with the related past research, the high Reynolds number is treated by large-scale computa...

A new approach based on hybrid Hopfield neural network and self-adaptive genetic algorithm for camera calibration is proposed. First, a Hopfield network based on dynamics is structured according to the normal equation obtained from experiment data. The network has 11 neurons, its weights are elements of the symmetrical matrix of the normal equation...

Two-dimensional compressible flows field for the interaction of shocks with the cylinder interface are directly simulated by using high order accurate upwind compact difference schemes with group velocity control combined with Level Set method. Numerical results are compared with the experimental observation. They show the right position of interfa...

The general method of constructing high-resolution schemes to solve 2D shallow water equations is studied. Using the technique of group velocity control, some high-resolution schemes are obtained, such as three-order upwind group velocity control schemes and four-order group velocity control schemes. Using the dispersion and anisotropy measurement,...