Qingang Xiong

• Ph.D
• Researcher at General Motors Company

A CFD-PBM is proposed to describe the distribution of particle size distribution (PSD) in the continuous oscillating baffled crystallizer (COBC). The model is first evaluated with the experimental data, the results show that the model can give reasonable predictions of profiles of pressure, solid concentration, and velocity of the liquid-solid flow...

The rapid devolatilization of biomass in chemical looping combustion could form a local plume of volatiles, reducing contact between volatiles and oxygen carriers and thus lowering gas conversion. Hence, a novel concept called volatiles distributor (VD) has been recently proposed to enhance the mixing between the volatiles and oxygen carriers. Howe...

In reactor-scale CFD modeling of biomass pyrolysis with thermally-thick particles, zero-dimensional (0D) models coupled with lumped kinetics are commonly used, as they are simple and computationally efficient. However, intra-particle heat transfer, which cannot be directly implemented in 0D models, has significant effects on pyrolysis behaviors of...

Computational fluid dynamics (CFD) is an effective tool to investigate biomass fast pyrolysis in fluidized bed reactor for bio-oil production, while it requires huge Computational time when optimizing operating conditions or simulating large/industrial units. Machine learning (ML) is a promising approach to achieving both accuracy and efficiency. I...

7 8 Exploring advanced electrocatalysts to accelerate the sluggish methanol oxidation reaction (MOR) in the anode of direct methanol fuel cells is a promising route to alleviate the current challenges of fossil fuel exhaustion and environmental pollution. Herein, we develop capping-free PdCo alloys with a coral-like structure and use them as potent...

In this study, we perform numerical simulations to investigate the thermal and flow characteristics of a parabolic trough solar collector equipped with a porous receiver tube and internal longitudinal fins. The heat transfer medium is a synthetic oil-Cu-Al2O3 hybrid nanofluid. We examine the thermal characteristics of the nanofluid in response to v...

Energy crises and environmental pollution are two of the cardinal obstacles that affect human life today. As part of the efforts to address the excessive energy demands in the last few decades is using renewable energy like solar. As the building sector continues to grow with the growing population, correspondingly, the demand for energy consumptio...

This research investigates the transient flame propagation and oscillation phenomenon in the flame speed of porous biochar dust cloud. Time-dependent mass, momentum and energy equations are solved in the spherical coordinate. The gas phase reaction includes the chemical reactions, thermodynamic properties, and multi-element transition properties. T...

Transport phenomena in a hybrid or single-particle nanofluid over a conical body embedded inside a porous medium are investigated. The fluid contains homogeneously mixed nanoparticles and live cells that are able to migrate, collectively sculpturing a thermo-biosolutal system. Transport processes including mixed convection as well as species and ce...

Solar collectors will play a very important role in absorbing solar renewable energy for use in various industries in the future of the world. This study looks at the resulting combination of using porous medium and hybrid nanofluids, in the presence of thermal radiation, on the thermo-hydrodynamic features, heat transfer, supply temperature, and h...

Over the years, nanofluids have proved to be beneficial in various heat transfer applications, particularly in solar energy collectors. Hybrid nanofluids have also shown promise in such applications due to their enhanced thermal conductivity relative to mono-nanofluids and to pure fluids. The aim of this review paper is to scrutinize recent researc...

In this study, a numerical model was introduced for simulation of preparation of TiO2 by non-premixed combustion of Ti particles in counter-flow arrangement. Preheating, reaction, melting, and vaporization processes were modeled using the asymptotic concept. To reach a viable model, convective and radiative heat losses were included in the model de...

Purpose The widespread usage of magnetic nanoparticles (MNPs) requires their efficient synthesis during combustion process. This study aims to present a mathematical model for the oxidation of MNPs in a counter-flow non-premixed combustion system to produce MNPs, where the key sub-processes during the oxidation reaction are involved. Design/method...

This study demonstrated the effect of conical and fusiform turbulators placed in double-pipe heat exchanger (DPHE) on the heat transportation and turbulent flow designs. A total of 21 configurations including conical and fusiform turbulator inserts are simulated in a double-pipe heat exchanger with circular and rectangular tube configurations at fo...

Nanofluids as a new generation of fluids have attracted a lot of research works. There is growing evidence that the nanofluids are more suitable for various heat transfer applications than the conventional fluids. One of the most important parameters in the thermal behavior of such fluids is the type of nanoparticles dispersed in the base fluid. Th...

In this study, adsorption of lactoferrin (Lf) and bovine serum albumin (BSA) nanoparticles on pellicular two-layer agarose-nickel immobilized by reactive blue 4 dye-ligand ([email protected]) was investigated. [email protected] was prepared using the three-phase emulsion method. The dynamic light scattering was first employed to quantify size distr...

Clear understanding of the characteristics on convective heat transfer in simple-configuration double-pipe heat exchangers will add great value to design of heat exchangers. In this work, an important while less investigated problem, i.e., turbulent forced convective heat transfer inside novel double-pipe heat exchangers with flat inner pipes, was...

Pyrolysis has created many (and will open more) possibilities for high-value utilization of biomass. To obtain the optimal amount of desired pyrolysis products, especially high-quality bio-oil, a great deal of effort has been conducted in both academia in the past few decades, to clarify fundamental mechanisms of biomass pyrolysis and design effici...

Natural convection of a fluid inside a closed square porous enclosure with inhomogeneous porosity distribution was studied numerically. The right and left walls of the cavity were cold and hot, respectively, provided the upper and lower walls were well insulated. The fluid and solid portions are in thermal equilibrium within the porous medium. Boun...

In this study, heterogeneous combustion of dust clouds containing polydisperse porous iron particles was numerically investigated. The main aim was to develop a discrete three-dimensional model to quantify the effects of particle size, porosity, cloud concentration, and polydispersity on flame propagation speed. The developed numerical model was va...

Experimental study Symmetric flat-plate solar collector TiO 2-water nanofluid Thermal efficiency ABSTRACT Flat-plate solar collectors are one of the cleanest and most efficient heating systems available. This experimental study explores the effect of replacing water with surfactant-free rutile TiO 2-water nanofluids as the working fluid in a symmet...

In order to reduce the computational effort of design and optimization for biomass fast pyrolysis reactor, the reduced-order modeling technology was applied to develop reduced-order models (ROMs) based on the CFD data from multi-fluid model (MFM) simulation of biomass fast pyrolysis in a bubbling fluidized bed reactor. The CFD simulations at nine d...

One of the major properties of biodiesel fuels is cetane number (CN) which expresses the ignition characteristics and quality of motor power. The main idea of this work was proposing an accurate model for estimation of the cetane number of biodiesel in terms of fatty acid methyl esters composition. In doing so, least-square support vector machine (...

In this study, the thermal and flow characteristics of a parabolic-trough solar collector have been numerically investigated. The turbulent flow inside the receiver tube was modeled via the finite volume method, while a non-uniform concentrated heat flux was imposed on the absorber tube. A Cu–water nanofluid was specified as the heat transfer fluid...

In this work, the density of biofuel is estimated using four intelligent models: a Least Square Support Vector Machine (LSSVM), a Radial Basis Function Artificial Neural Network (RBF-ANN), a Multi-layer Perceptron Artificial Neural Network (MLP-ANN), and an Adaptive Network-based Fuzzy Inference System (ANFIS). These models are used to estimate the...

Hydrodynamics of wet fluidized beds is significantly affected by the liquid bridge force between solid particles. In this study, two-fluid modeling of wet fluidizations with wet restitution coefficient model was realized in Ansys Fluent® through its user-defined function portal. Wet restitution coefficient was calculated using the sub-model propose...

Nonlinear mixed convection of heat and mass in a stagnation-point flow of an impinging jet over a solid cylinder embedded in a porous medium is investigated by applying a similarity technique. The problem involves a heterogenous chemical reaction on the surface of the cylinder and nonlinear heat generation in the porous solid. The conducted analysi...

Computational fluid dynamics (CFD) simulation of combustible solid waste (CSW) pyrolysis in a fluidized bed reactor with feeding rate of 5 kg/h was performed in this study. The multi-phase flow was simulated using the Euler-Euler method, and a multi-component and multi-step reaction method was adopted to describe the pyrolysis process of CSW. The u...

In this study, impingement cooling of a porous metal CPU cooler saturated with nanofluid under the effects of magnetic field was modeled analytically. Darcy-Brinkman-Forchheimer model and viscous dissipation effect were considered to simulate fluid flow of nanofluid through the porous media under magnetic field. Proper similarity variables were pro...

In this numerical study, discrete combustion of polydisperse magnesium dust clouds was investigated. A numerical model accounting for the effects of ignition, thermal conduction, and radiation was formulated to simulate the spatiotemporal distribution of temperature. Three distribution models, i.e., Dagum, log-normal, and Beta prime, were used to d...

In current report, hybrid nanofluid free convection within a permeable media has been modeled via CVFEM including magnetic effect. To obtain the momentum equations, permeambility was involved via Non-Darcy model. Hybrid nanoparticle (Fe3O4+MWCNT) with base fluid of water has been considered. Source tem of radiation impact was icoporated. To obtain...

This study proposed a promising analytical solution for transient heat conduction in an infinite geometry with general heat source under heterogeneous time-dependent boundary conditions of the third kind at both internal and external surfaces. Due to the inherent heterogeneity of the problem and its associated boundary conditions, the analytical so...

In this paper, to demonstrate the behavior of NEPCM during discharging within a triplex tank, numerical approach has been utilized. Reduction of entropy generation due to adding nanoparticle can help to get better performance of unit. Outcomes reveal that temperature declines with adding nanoparticles while needed time for solidification reduces. R...

This research investigates the behavior of ethanol and biodiesel, blended with diesel fuel in a multiple injection engine. Numerical study and engine simulation were carried out using ESE Diesel environment of AVL Fire. The simulations were conducted for 10 and 20% biofuel blends and also, 20 and 30% pilot injection and for two different injection...

This study mathematically presents a counterflow non-premixed thermochemical technique for preparing a particle oxide used for cancer diagnosis and treatment. For this purpose, preheating, reaction, melting, and oxidation processes were simulated considering an asymptotic concept. Mass and energy conservation equations in dimensional and non-dimens...

The performance of solar water heaters can be enhanced via a number of different methods. One such method involves altering the geometry of the collector. In this study, a symmetrical flat-panel solar collector with circular geometry has been experimentally evaluated. The collector has an area of one square meter, is free of risers and features spi...

In this work, a novel integrated gasification system was developed for wet microalgae to produce hydrogen-rich syngas and electricity. The proposed system consists of six major stages: (i) in-situ drying of wet microalgae, (ii) pyrolysis of dried microalgae, (iii) conversion of tar (produced in the pyrolysis stage), (iv) gasification of pyrolysis p...

In the present study, a finite volume method is used to investigate heat transfer and flow friction behavior of non-Newtonian nanofluids. To study a practical application of the mentioned concept, a simple model of a parabolic trough solar receiver is simulated. The main objective of the present study is to investigate the effect of non-Newtonian b...

In this study, a finite volume method is employed to investigate the performance of a novel parabolic trough solar collector with synthetic oil–Al2O3 nanofluid as the heat transfer fluid. An annular porous structure is installed inside the absorber tube to improve heat transfer. The effects of the simultaneous utilization of porous structure and na...

A numerical analysis of Copper oxide-H2O nanomaterial hydrothermal characteristics through a duct with utilizing turbulator under constant heat flux has been carried out by means of FVM. Simulations contain the effect of width tape (b) and Reynolds number (Re). Single phase model for nanomaterial and k-ɛ for turbulence modeling have been selected....

Unconventional feedstocks, such as heavy vacuum residue (VR), have become potential candidates that could be positively exploited to meet the increasing demand of high-value transportation fuels in view of the growing scarcity in other energy sources. However, such feeds contain extremely high molecular weight species besides many impurities of het...

Purpose Because of the appreciable application of heat recovery systems for the increment of overall efficiency of micro gas turbines, promising evaluation and optimization are crucial. This paper aims to propose a multi-factor theoretical methodology for analysis, optimization and comparison of potential plate-fin recuperators incorporated into mi...

Charging of PCM with incorporating copper oxide nanomaterial has been modeled in current article. Unsteady simulation for reporting thermal irreversibility was performed. Nanoparticles have been dispersed into paraffin to achieve greater efficiency and reach the match between demand and supply of energy. To increase the stored energy, volume fracti...

In this exploration, to control the convection of alumina nanofluid, Lorentz forces was incorporated and porous region was modeled via non-Darcy approach. In governing formulas, radiation impact was involved and nanoparticles shape for estimating behavior of nanomaterial was considered. Roles of magnetic, radiation parameters, Rayleigh number and n...

In this paper, a numerical investigation is performed on the flow and thermal performance of a heat sink, covered with an open cell metal foam, under the influences of uniform and non-uniform velocity impinging jets. Hydrogen, air and Cu-water nanofluid are considered as the cooling fluids. Navier-Stokes PDEs including the porous drag induced terms...

This communication presents the synergistic role of ceria and alumina support type, in the gasification of glucose/toluene as biomass/tar model compounds over Ni/Ce–Al2O3. Two catalysts having 20 wt% nickel on a mesoporous Ce(x)-mesoAl2O3 (x = 0 or 1) were prepared via successive incipient wetness impregnation method. Two similar catalysts (i.e. Ni...

In this work, the performance of a novel configuration for Spirulina microalgae gasification was investigated through an improved thermodynamic model using Aspen Plus. Compared with existing thermodynamic models, tar formation is included in the improved counterpart. The proposed novel gasification process consists of four primary zones: (i) pyroly...

This study numerically characterizes the combined effects of particle shrinkage and intra-particle heat conduction on biomass fast pyrolysis using computational fluid dynamics (CFD). The so-called multi-fluid model (MFM) was employed to simulate hydrodynamics and biomass fast pyrolysis was modeled by a lumped kinetics. The particle shrinkage and in...

In this study, mixed convection heat transfer of the non-Newtonian power-law nanofluid including CuO nanoparticles, inside a partially porous square enclosure with a concentric rotating cylinder and a hot side wall is numerically investigated. Two-phase mixture model is utilized for nanofluid flow simulation and the mixture viscosity and thermal co...

Biomass pyrolysis and gasification are two novel and popular approaches to convert low energy-density raw biomass into high energy-density bio-oil and gas for fuel and chemical engineering. They have been viewed as potential ways to complement traditional fossil fuels to increase energy security and reduce environmental pollution. various studies d...

Accurate and sensitive nanoscale thermal probing for thermophysical property characterization is appealing but still a challenge to date. Previous studies have revealed that graphene quantum dots (GQDs) are good temperature markers for their small dimension and superior fluorescence excitation. In this work, we show that the thermal response of flu...

Process intensification is critical to increase product yields and reduce external power consumption in biomass pyrolysis. Computational fluid dynamics offers great possibilities for fast and economical process intensification of biomass pyrolysis. This succinct but in-depth current-perspective feature article discusses the major trends and roadblo...

An improved bubble-based heterogeneous drag model was formulated in which the original bubble-based EMMS drag model at macroscale bed level was extended to microscale sub-grid level for accurate coarse-grid two-fluid modeling (TFM) of Geldart A powder bubbling fluidization. At both the macroscale and microscale levels, the physically heterogeneous...

This paper presents an analytical model to investigate the effect of randomly distributed micro-organic dust particles on the flame propagation through the combustible mixture by considering the thermal resistance and temperature difference between the gas and the particles. The effect of thermal resistance on flame characteristics is intended by t...

In this work, a series of ceria and sulfated zirconia (SZ) incorporated mesoporous SBA-15 catalysts were prepared via layer-by-layer grafting and subsequent wet impregnation methods. And the obtained catalysts were well characterized by SEM, TEM, XRD, TG, ICP-OES, PY-IR, NH3/CO2-TPD, and XPS. The catalytic activity of the prepared SBA-15 supported...

Exploring advanced electrocatalysts to accelerate the sluggish methanol oxidation reaction (MOR) in the anode of direct methanol fuel cells is a promising route to alleviate the current challenges of fossil fuel exhaustion and environmental pollution. Herein, we develop capping-free PdCo alloys with a coral-like structure and use them as potential...

In this work, a novel route to deconstruct cellulose into 5-hydroxymethylfurfural (HMF) by cascading enzymatic and chemical reactions is reported. For biocatalyst preparation, Fe3O4 nanoparticles encapsulated SBA-15 with appropriate pore size was synthesized and utilized as magnetic scaffolds for the immobilization of cellulase. For chemical cataly...

In this work we intercalated an Ag layer between Pd surface and Ni substrate to form PdAg/Ni ternary architectures to promote the sluggish methanol oxidation reaction (MOR). The PdAg/Ni foam structures were prepared within short time via a cascade galvanic replacement method, in which an Ag precursor partially replaced a commercial Ni foam support...

Computational fluid dynamics (CFD) has been widely used in both scientific studies and industrial applications of reactor-scale biomass pyrolysis. In this Perspective, the state-of-the-art progress in CFD modeling of reactor-scale biomass pyrolysis was summarized and discussed. First, because of the importance of biomass pyrolysis reaction kinetics...

Abstract Phosphorene is a recently discovered member of the two-dimensional (2D) monolayer materials, which has been reported to exhibit unique characteristics on mechanical and thermal properties. This study is the first time to show the exceptional thermal conductance between phosphorene and crystalline silicon substrate through classical molecul...

We report results from a computational study of the transition from bubbling to slugging in a laboratory-scale fluidized-bed reactor with Geldart Group B glass particles. For simulating the three-dimensional fluidized-bed hydrodynamics, we employ MFiX, a widely studied multi-phase flow simulation tool, that uses a two-fluid Eulerian-Eulerian approx...

In this work, a green reaction system of CO2-water-isopropanol was developed for 5-hydroxymethylfurfural (HMF) production. The conversion of fructose in a CO2-water system was first investigated, and the results showed this system could promote the formation of HMF compared to a pure water system. Then, isopropanol was introduced into the CO2-water...

Pyrolysis is an important process encountered in direct combustion, gasification, and fast pyrolysis of solid biomass materials. This paper describes a computational study on biomass pyrolysis, at particle scale, considering the intra-particle transport phenomena and flow fields surrounding the particles. The lattice Boltzmann method, chosen to sol...

In this study, macroporous inorganic–organic hybrid polymers (MIPs) were prepared using versatile high internal phase emulsions (HIPEs) templating to synthesize a novel catalyst for cellulose conversion. Upon the incomplete hydrothermal carbonization of MIPs and sulfonation with H2SO4, macroporous carbonaceous solid catalysts (MCSC) with hierarchic...

We propose a wavelet-based scheme that encodes the essential dynamics of discrete microscale surface reactions in a form that can be coupled with continuum macroscale flow simulations with high computational efficiency. This makes it possible to simulate the dynamic behavior of reactor-scale heterogeneous catalysis without requiring detailed concur...

Herein we reported a simple and novel synthetic strategy for the fabrication of two kinds of hydrophobic polymer foam catalysts (i.e. Cr3+-HPFs-1-H+ and HPFs-1-H+) with hierarchical porous structure, inhomogeneous acidic composition and Lewis–Brønsted double acid sites distributed on the surface, which was used to one-pot conversion of carbohydrate...

We report results from computational simulations of an experimental, lab-scale bubbling bed biomass pyrolysis reactor that include a distributed activation energy model (DAEM) for the kinetics. In this study, we utilized multiphase computational fluid dynamics (CFD) to account for the turbulent hydrodynam-ics, and this was combined with the DAEM ki...

This review summarizes the state-of-the-art progress in the molecular dynamics (MD) simulation of graphene's novel thermal properties. Graphene's novel thermal properties, including anisotropic thermal conductivity, decoupled phonon thermal transport, thermal rectification, and tunable interfacial thermal conductance, have attracted enormous intere...

Three devolatilization schemes to simulate biomass fast pyrolysis were tested and validated in this study. Fast pyrolysis is an attractive process in converting lignocellulosic biomass to valued products. Accurate numerical models can help understand the conversion process and be used for reactor design and optimization. This study used a numerical...

A numerical study was conducted to investigate the validity of using the spring-backed membrane model for compliant walls (CWs), and to explain the failure of the reference study [Duncan and Zhang, Journal of Fluid Mechanics 1991, (226) 401-423] to reproduce the bubble behavior near moderately elastic CWs. The same mathematical models used in the r...

The lattice Boltzmann method (LBM) for simulating fluid phases was coupled with the discrete element method (DEM) for studying solid phases to formulate a novel solver for fast discrete particle simulation (DPS) of particle-fluid flows. The fluid hydrodynamics was obtained by solving LBM equations instead of solving the Navier-Stokes equation by th...

A numerical study of the effects of the shape of an enclosed screw conveyor on the mixing and heat transfer in a horizontal gas-solid fluidized bed was conducted using computational fluid dynamics (CFD). A two-fluid model (TFM) was employed to model the gas and solid phases as continua through mass, momentum, and energy conservations. The motion of...

This numerical study investigates the effects of operating conditions on the product yields of a biomass fast pyrolysis reactor. A numerical approach that combines a multifluid model and pyrolysis reaction kinetics was applied to simulate the biomass fast pyrolysis process in a bubbling fluidized-bed reactor. The model was first validated using exp...