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Particuology 2022年第8期20卷 47-56页

作者： Pilaiwan Chaiwang Hannarong Chitcharoenyoo Pornpote Piumsomboon Benjapon Chalermsinsuwan Fuels Rsearch Centerpartment of Chemical Tchnology Faculty of Science Chulalongkon University 254 Phyathai RadWangmaiPathumwan Bangkok 10330Thailand Program in Petrochemistry and Polymer Science Faculty of ScienceChulalongkorn University.254 Phyathai Road WangmaiPathumwanBangok 10330Thailand Centero Eellenceon Perochemicaland Materials Techology Chulalongorn Universy 254 Phyathai Road WangmaiathumwanBangkok 10330.Thailand Advanced Computational Fuidynamics Research Unit Chulalongkom Universy254 Phyathai RoadWangmai Pathumwan Bangkok 10330Thailand

The three-dimensional computational fuid dynamics(3D-CFD)of a pulsating flow applied to the fluid catalytic cracking(FCC)reaction was investigated in the riser of a circulating fluidized bed *** kinetic parameters of the FCC and coke burning reactions for predicting the reactant conversion and product yield percentages were *** increase the reactant conversion level and product *** effect of the pulsating flow operating parameters was considered using a 2k statistical experimental design with four factors(amplitude,frequency,types of the waveform,and amplitude ratio).The 3DCFD simulation was successfully validated from the experimental literature *** frequency and type of the waveform were found to be the significant operating *** expression of the fitted regression model and response surface contour were derived and revealed that the pulsating flow provides a higher reactant conversion level and product yield percentages compared to a non-pulsating or steady flow.

关键词： Fluidcatalytic cracking Circulating fluidized bed riser computationalfluid dynamics Pulsating Statistical experimental design

Computational fluid dynamics applied to high temperature hydrogen separation membranes

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Frontiers of Chemical Science and Engineering 2012年第1期6卷 3-12页

作者： Guozhao JI Guoxiong WANG Kamel HOOMAN Suresh BHATIA Joao C. DINIZ da COSTA School of Chemical Engineering the University of Queensland Brisbane 4072 Australia School of Mechanical and Mining Engineering the University of Queensland Brisbane 4072 Australia

This work reviews the development of computational fluid dynamics （CFD） modeling for hydrogen separation, with a focus on high temperature membranes to address industrial requirements in terms of membrane systems as contactors, or in membrane reactor arrange- ments. CFD modeling of membrane,.s attracts interesting challenges as the membrane provides a discontinuity of flow, and therefore cannot be solved by the Navier-Stokes equations. To address this problem, tile concept of source has been introduced to understand gas flows on both sides or domains （feed and permeate） of the membrane. This is an important solution, as the gas flow and concentrations in the permeate domain are intrinsically affected by the gas flow and concentrations in the feed domain and vice-versa. In turn, the source term will depend on the membrane used, as different membrane materials comply with different transport mechanisms, in addition to varying gas selectiv- ity and fluxes. This work also addresses concentration polarization, a common effect in membrane systems, though its significance is dependent upon the performance of the membrane coupled with the operating conditions. Finally, CFD modeling is shifting from simplified single gas simulation to industrial gas mixtures, when the mathematical treatment becomes more complex.

关键词： membrane gas separat:ion computationalfluid dynamics concentration polarization hydrogen

Modeling of rotational supercavitating evaporator and the geometrical characteristics of supercavity within

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Science China(Physics,Mechanics & Astronomy) 2014年第3期57卷 541-554页

作者： LIKHACHEV Dmitriy S. LI FengChen Complex Flow and Heat Transfer Laboratory School of Energy Science and EngineeringHarbin Institute of Technology

In this paper,a rotational supercavitating evaporator(RSCE)was at first modeled by means of theoretical analysis *** geometrical characteristics of supercavity in the modeled RSCE were then studied through numerical *** current research objectives consist in determination of shape of the supercavitator(which in the plane of rotation generates supercavity occupying the most volume between blades),and location of the area suitable for steam extraction by revealing the inner structure of *** analysis was performed by solving empirical equations for the shape of RSCE,through which an evaluation of two-dimensional relative position of supercavity trailing edge for different shapes of the supercavitator has been *** simulation was then carried out,by numerically solving the unsteady Navier-Stokes equations in their conservation form coupled with the Rayleigh-Plesset cavitation and Shear-Stress Transport turbulence models,for verification of the results obtained from empirical *** unreliable assumption of applicability of empirical equations we have confirmed similarity of the supercavity shapes obtained by both methods for the same ***,the shape of supercavitator calculated by using empirical equations is acceptable,which provides a simple but reliable approach for design of *** inner structure of supercavity obtained by numerical simulation has indicated position and parameters for steam extraction openings for further numerical and experimental studies on the performance of *** application of steam or gas extraction is suggested for solving of some problems associated with cavitating pumping of cryogenic liquid.

关键词： supercavitation rotational supercavitating evaporator geometrical characteristics theoretical analysis computationalfluid dynamics

A multi-objective and CFD based optimization of roof-flap geometry and position for simultaneous drag and lift reduction

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Propulsion and Power Research 2024年第1期13卷 26-45页

作者： Mohammad Rostamzadeh-Renani Mohammadreza Baghoolizadeh S.Mohammad Sajadi Reza Rostamzadeh-Renani Narjes Khabazian Azarkhavarani Soheil Salahshour Davood Toghraie Energy Department Politecnico di MilanoVia Lambruschini 4Milan 20156Italy Department of Mechanical Engineering Shahrekord UniversityShahrekord 88186-34141Iran Department of Nutrition Cihan University-ErbilKurdistan RegionIraq Department of Mechanical Engineering Jami Institute of TechnologyIsfahanIran Faculty of Engineering and Natural Sciences Istanbul Okan UniversityIstanbulTurkey Faculty of Engineering and Natural Sciences Bahcesehir UniversityIstanbulTurkey Department of Computer Science and Mathematics Lebanese American UniversityBeirutLebanon Department of Mechanical Engineering Khomeinishahr BranchIslamic Azad UniversityKhomeinishahrIran

As the transport sector is responsible for the consumption of a vast proportion of the oil produced,it is mandatory to research feasible solutions to tackle this *** appli-cation of aerodynamic attachments for passiveflow control and reducing resisting aerodynamic forces such as drag and lift is one of the most practicable ways to minimize vehicle energy *** are one of the most innovative aerodynamic attachments that can enhance theflow motion in the boundary layer at the trailing edge of the *** the present paper,theflap is designed and modeled for controlling the airflow at the roof-end of a 2D Ahmed body model,inspired by the schematic of theflap at the trailing edge of the *** a result,theflap’s geometry and position from the roof-end of the car model are parameterized,which leads to having four design *** objective functions of the present study are the vehicle’s drag coefficient and lift coefficient.25 Design of Experiment(DOE)points are considered enabling the Box-Behnken ***,each DOE point is modeled in the computational domain,and theflow-field around the model is simulated using Ansys Fluent *** results obtained for the DOE points are employed by different regressors,and the relation between design variables and objective functions is extracted using *** GMDH-ANN is then coupled with three types of optimization algorithms,among which the Genetic algorithm proves to have the most ideal coupling process for ***,af-ter analyzing the variations in the geometry and position of the roofflap from the car roof-end,the roof-flap with specifications of L=0.1726 m,a=5.0875°,H=0.0188 m,and d=0.241 m can optimize the car drag and lift coefficients by 21.27% and 19.91%,*** present research discusses the opportunities and challenges of optimal design roof-flap geometry and its influence on car aerodynamic performance.

关键词： Drag coefficient Lift coefficient Roofflap computationalfluid dynamics Artificial neural

Distribution of wall shear stress in carotid plaques using magnetic resonance imaging and computational fluid dynamics analysis： a preliminary study

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Chinese Medical Journal 2011年第10期124卷 1465-1469页

作者： JING Li-na GAO Pei-yi LIN Yan SUI Bin-bin QIN Hai-qiang MA Li XUE Jing Department of Radiology Affiliated Beijing Tiantan Hospital Capital Medical University Beijing 100050 China Department of Neurology Affiliated Beijing Tiantan Hospital Capital Medical University Beijing 100050 China

Background Wall shear stress is an important factor in the destabilization of atherosclerotic plaques. The purpose of this study was to assess the distribution of wall shear stress in advanced carotid plaques using high resolution magnetic resonance imaging and computational fluid *** Eight diseased internal carotid arteries in seven patients were evaluated. High resolution magnetic resonance imaging was used to visualize the plaque structures, and the mechanic stress in the plaque was obtained by combining vascular imaging post-processing with computational fluid *** Wall shear stresses in the plaques in all cases were higher than those in control group. Maximal shear stresses in the plaques were observed at the top of plaque hills, as well as the shoulders of the plaques. Among them,the maximal shear stress in the ruptured plaque was observed in the rupture location in three cases and at the shoulder of fibrous cap in two cases. The maximal shear stress was also seen at the region of calcification, in thrombus region and in the thickest region of plaque in the other three cases, *** Determination of maximal shear stress at the plaque may be useful for predicting the rupture location of the plaque and may play an important role in assessing plaque vulnerability.

关键词： atherosclerosis carotid artery computationalfluid dynamics magnetic resonance imaging wall shear stress