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2-D Modeling and Calculations of Stratospheric Ozone and Influences of Convection, Diffusion, and Time
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作者 Ibraheem Alelmi Laurie Wei Sen Nieh 《Atmospheric and Climate Sciences》 2024年第2期250-276,共27页
An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical react... An engineering system approach of 2-D cylindrical model of transient mass balance calculations of ozone and other concerned chemicals along with fourteen photolysis, ozone-generating and ozone-depleting chemical reaction equations was developed, validated, and used for studying the ozone concentrations, distribution and peak of the layer, ozone depletion and total ozone abundance in the stratosphere. The calculated ozone concentrations and profile at both the Equator and a 60˚N location were found to follow closely with the measured data. The calculated average ozone concentration was within 1% of the measured average, and the deviation of ozone profiles was within 14%. The monthly evolution of stratospheric ozone concentrations and distribution above the Equator was studied with results discussed in details. The influences of slow air movement in both altitudinal and radial directions on ozone concentrations and profile in the stratosphere were explored and discussed. Parametric studies of the influences of gas diffusivities of ozone D<sub>O3</sub> and active atomic oxygen D<sub>O</sub> on ozone concentrations and distributions were also studied and delineated. Having both influences through physical diffusion and chemical reactions, the diffusivity (and diffusion) of atomic oxygen D<sub>O</sub> was found to be more sensitive and important than that of ozone D<sub>O3</sub> on ozone concentrations and distribution. The 2-D ozone model present in this paper for stratospheric ozone and its layer and depletion is shown to be robust, convenient, efficient, and executable for analyzing the complex ozone phenomena in the stratosphere. . 展开更多
关键词 Stratospheric Ozone 2-d model Ozone Layer Ozone Depletion CONVECTION DIFFUSION
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Coupled 2D Hydrodynamic and Sediment Transport Modeling of Megaflood due to Glacier Dam-break in Altai Mountains,Southern Siberia 被引量:6
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作者 HUANG Wei CAO Zhi-xian +1 位作者 Paul CARLING Gareth PENDER 《Journal of Mountain Science》 SCIE CSCD 2014年第6期1442-1453,共12页
One of the largest known megafloods on earth resulted from a glacier dam-break,which occurred during the Late Quaternary in the Altai Mountains in Southern Siberia.Computational modeling is one of the viable approache... One of the largest known megafloods on earth resulted from a glacier dam-break,which occurred during the Late Quaternary in the Altai Mountains in Southern Siberia.Computational modeling is one of the viable approaches to enhancing the understanding of the flood events.The computational domain of this flood is over 9460 km2 and about 3.784 × 106 cells are involved as a 50 m × 50 m mesh is used,which necessitates a computationally efficient model.Here the Open MP(Open Multiprocessing) technique is adopted to parallelize the code of a coupled 2D hydrodynamic and sediment transport model.It is shown that the computational efficiency is enhanced by over 80% due to the parallelization.The floods over both fixed and mobile beds are well reproduced with specified discharge hydrographs at the dam site.Qualitatively,backwater effects during the flood are resolved at the bifurcation between the Chuja and Katun rivers.Quantitatively,the computed maximum stage and thalweg are physically consistent with the field data of the bars and deposits.The effects of sediment transport and morphological evolution on the flood are considerable.Sensitivity analyses indicate that the impact of the peak discharge is significant,whilst those of the Manningroughness,medium sediment size and shape of the inlet discharge hydrograph are marginal. 展开更多
关键词 Glacier dam-break flood Well-balanced 2D hydrodynamic and sediment transport model Open MP parallelization
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冲击电弧作用下C_(4)F_(7)N/CO_(2)气体灭弧性能仿真分析 被引量:1
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作者 吴东 陈文贵 《电力工程技术》 北大核心 2024年第2期179-188,共10页
C_(4)F_(7)N/CO_(2)混合气体是目前最有潜力替代SF 6的气体之一。为了探讨C_(4)F_(7)N/CO_(2)混合气体的灭弧能力,文中根据电弧能量平衡理论,建立电弧能量平衡方程组,获取管道内部超压随时间的变化规律。同时,基于磁流体动力学模型,使用... C_(4)F_(7)N/CO_(2)混合气体是目前最有潜力替代SF 6的气体之一。为了探讨C_(4)F_(7)N/CO_(2)混合气体的灭弧能力,文中根据电弧能量平衡理论,建立电弧能量平衡方程组,获取管道内部超压随时间的变化规律。同时,基于磁流体动力学模型,使用COMSOL Multiphysics软件建立压爆气流防雷间隙灭弧结构的二维磁流体模型,在雷电流幅值为4 kA的条件下,对管道内不同比例C_(4)F_(7)N/CO_(2)混合气体在冲击电弧作用下的熄弧特性进行仿真分析。基于上述方法,结合电弧能量平衡理论,分析模型中电导率、速度以及压强的变化规律。与理论结果对比分析得出:同一工况条件下,20%C_(4)F_(7)N/80%CO_(2)的灭弧性能较优,其次为10%C_(4)F_(7)N/90%CO_(2)与5%C_(4)F_(7)N/95%CO_(2),并且熄弧时间符合气吹灭弧的要求。 展开更多
关键词 C_(4)F_(7)N/CO_(2)混合气体 灭弧性能 电弧能量平衡理论 磁流体动力学模型 冲击电弧 熄弧时间
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Calculations and Sensitivity Analysis of Chlorine-,NO_(x)-,and Bromine-Depleting Cycles of Stratospheric Ozone
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作者 Ibraheem Alelmi Sen Nieh 《Journal of Environmental Science and Engineering(B)》 CAS 2024年第2期53-69,共17页
This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozon... This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere. 展开更多
关键词 Ozone depletion 2-d model CHLORINE BROMINE nitrogen oxides sensitivity analysis total ozone abundance DU
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Interannual variability of carbon cycle implied by a 2-D atmospheric transport model
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作者 LICan XULi ZHANGRen-jian 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第5期779-783,共5页
A 2-dimensional atmospheric transport model is deployed in a simplified CO 2 inverse study. Calculated carbon flux distribution for the interval from 1981 to 1997 confirms the existence of a terrestrial carbon sink i... A 2-dimensional atmospheric transport model is deployed in a simplified CO 2 inverse study. Calculated carbon flux distribution for the interval from 1981 to 1997 confirms the existence of a terrestrial carbon sink in mid-high latitude area of North Hemisphere. Strong interannual variability exists in carbon flux patterns, implying a possible link with ENSO and other natural episodes such as Pinatubo volcano eruption in 1991. Mechanism of this possible link was investigated with statistic method. Correlation analysis indicated that in North Hemisphere, climatic factors such as temperature and precipitation, to some extend, could influence the carbon cycle process of land and ocean, thus cause considerable change in carbon flux distribution. In addition, correlation study also demonstrated the possible important role of Asian terrestrial ecosystems in carbon cycle. 展开更多
关键词 2-d transport model inverse study carbon cycle ENSO interannual variability
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A 2-D Non-local Closure Model for Atmospheric Boundary Layer Simulations
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作者 蒋维楣 王雪梅 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第2期169-182,共14页
In this paper a new approach for PBL simulation, the non-local closure scheme based on the transient turbulence theory has been used. It was set up as an alternative to local closure schemes which physical concept is ... In this paper a new approach for PBL simulation, the non-local closure scheme based on the transient turbulence theory has been used. It was set up as an alternative to local closure schemes which physical concept is reasonable and distinct. A 2-D non-local closure model was developed in order to study the PBL structure and simulatesome interesting atmospheric processes over non-ulliform underlying surface, especially under the convective and unique weather conditions, such as sea-land circulation and the TIBL structure. The modelled results show good agreement with field measurement. 展开更多
关键词 Non-local closure 2-d numerical model The PBL simulation Non-uniform underlying surface
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Source Rock Evaluation and 1-D Basin Modelling Approach for the Sargelu Formation, Atrush-2 Well, Kurdistan Region-Iraq
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作者 Revan Akram Ayad N. F. Edilbi +2 位作者 Wrya J. Mamaseni Govand H. Sherwani Nadhir Al-Ansari 《Open Journal of Geology》 2021年第3期49-60,共12页
The present study focuses on source rock evaluation of the Sargelu Formation by using core chips of rocks collected from well Atrush-2, Duhok, Kurdistan Region-Iraq. The Rock-Eval pyrolysis and vitrinite reflectance w... The present study focuses on source rock evaluation of the Sargelu Formation by using core chips of rocks collected from well Atrush-2, Duhok, Kurdistan Region-Iraq. The Rock-Eval pyrolysis and vitrinite reflectance were executed. Subsequently, the selected parameters were used for source rock evaluation and 1-D Basin Modelling calibration. The upper part of the formation mainly comprises argillaceous limestone with low content of organic matter (0.64% - 1% TOC). By contrast, the lower part is dominated with shale interval and contains high amounts of TOC values (>4% for 1272 - 1278 m) reveling good to very good quality source rock. Accordingly, good to very good hydrocarbon generation potential is suggested for this formation. Organic matter of the Sargelu Formation contains type II and mixed-type II-III kerogen. The values of Tmax and vitrinite reflectance (Ro%) demonstrate that the formation is thermally mature and in the oil zone. In order to construct a thermal history of the formation and determine the timing of hydrocarbon maturation and generation, the 1-D basin modelling PetroMod 2019.1 was used in this study. Based on the 1-D Basin modelling simulation and its outputs, about 3500 m of overburden have been eroded at the study area. The present-day heat flow was found to be 30 mW/m2. The organic matter of Sargelu Formation entered the early oil zone in 64 Ma and reached the main oil zone ca. 5 Ma. The formation is still in the main oil zone at present-day. In well Atrush-2, the highest rate of oil generation for the Sargelu Formation was in the 8.5 Ma, the onset of oil expulsion from Sargelu Formation was in 50 Ma and the expulsion mass has been reached 0.5 Mtons at present-day. 展开更多
关键词 Sargelu Formation Source Rock Well Atrush-2 1-d Basin modelling Iraq
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A Survey on the Stability of 2-D Discrete Systems Described by Fornasini-Marchesini Second Model
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作者 Manish Tiwari Amit Dhawan 《Circuits and Systems》 2012年第1期17-22,共6页
A key issue of practical importance in the two-dimensional (2-D) discrete system is stability analysis. Linear state-space models describing 2-D discrete systems have been proposed by several researchers. A popular mo... A key issue of practical importance in the two-dimensional (2-D) discrete system is stability analysis. Linear state-space models describing 2-D discrete systems have been proposed by several researchers. A popular model, called Forna- sini-Marchesini (FM) second model was proposed by Fornasini and Marchesini in 1978. The aim of this paper is to present a survey of the existing literature on the stability of FM second model. 展开更多
关键词 2-d Discrete Systems FM SECOND model ASYMPTOTIC Stability LYAPUNOV Methods
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Non-Fragile Controller Design for 2-D Discrete Uncertain Systems Described by the Roesser Model
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作者 Amit Dhawan 《Journal of Signal and Information Processing》 2012年第2期248-251,共4页
This paper is concerned with the design problem of non-fragile controller for a class of two-dimensional (2-D) discrete uncertain systems described by the Roesser model. The parametric uncertainties are assumed to be ... This paper is concerned with the design problem of non-fragile controller for a class of two-dimensional (2-D) discrete uncertain systems described by the Roesser model. The parametric uncertainties are assumed to be norm-bounded. The aim of this paper is to design a memoryless non-fragile state feedback control law such that the closed-loop system is asymptotically stable for all admissible parameter uncertainties and controller gain variations. A new linear matrix inequality (LMI) based sufficient condition for the existence of such controllers is established. Finally, a numerical example is provided to illustrate the applicability of the proposed method. 展开更多
关键词 2-d DISCRETE Systems NON-FRAGILE Control Roesser model Linear MATRIX INEQUALITY LYAPUNOV Methods
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Delay-Dependent Robust H Control for Uncertain 2-D Discrete State Delay Systems Described by the General Model
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作者 Arun Kumar Singh Akshata Tandon Amit Dhawan 《Circuits and Systems》 2016年第11期3645-3669,共25页
This paper considers the problem of delay-dependent robust optimal H<sub>∞</sub> control for a class of uncertain two-dimensional (2-D) discrete state delay systems described by the general model (GM). Th... This paper considers the problem of delay-dependent robust optimal H<sub>∞</sub> control for a class of uncertain two-dimensional (2-D) discrete state delay systems described by the general model (GM). The parameter uncertainties are assumed to be norm-bounded. A linear matrix inequality (LMI)-based sufficient condition for the existence of delay-dependent g-suboptimal state feedback robust H<sub>∞</sub> controllers which guarantees not only the asymptotic stability of the closed-loop system, but also the H<sub>∞</sub> noise attenuation g over all admissible parameter uncertainties is established. Furthermore, a convex optimization problem is formulated to design a delay-dependent state feedback robust optimal H<sub>∞</sub> controller which minimizes the H<sub>∞</sub> noise attenuation g of the closed-loop system. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed method. 展开更多
关键词 2-d Discrete System General model H Control Linear Matrix Inequality State Delays Uncertain System
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Robust Optimal H Control for Uncertain 2-D Discrete State-Delayed Systems Described by the General Model
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作者 Arun Kumar Singh Amit Dhawan 《Journal of Signal and Information Processing》 2016年第2期78-114,共17页
This paper investigates the problem of robust optimal H<sub>∞</sub> control for uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model (GM) with norm-bounded uncerta... This paper investigates the problem of robust optimal H<sub>∞</sub> control for uncertain two-dimensional (2-D) discrete state-delayed systems described by the general model (GM) with norm-bounded uncertainties. A sufficient condition for the existence of g-suboptimal robust H<sub><sub></sub></sub><sub>∞</sub> state feedback controllers is established, based on linear matrix inequality (LMI) approach. Moreover, a convex optimization problem is developed to design a robust optimal state feedback controller which minimizes the H<sub><sub><sub></sub></sub></sub><sub>∞</sub> noise attenuation level of the resulting closed-loop system. Finally, two illustrative examples are given to demonstrate the effectiveness of the proposed method. 展开更多
关键词 2-d Discrete Systems General model H Control Linear Matrix Inequality State Feedback Uncertain System
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Simulation of Cavitating Flow around a 2-D Hydrofoil 被引量:7
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作者 黄胜 何苗 +1 位作者 王超 常欣 《Journal of Marine Science and Application》 2010年第1期63-68,共6页
In order to predict the effects of cavitation on a hydrofoil, the state equations of the cavitation model were combined with a linear viscous turbulent method for mixed fluids in the computational fluid dynamics (CFD)... In order to predict the effects of cavitation on a hydrofoil, the state equations of the cavitation model were combined with a linear viscous turbulent method for mixed fluids in the computational fluid dynamics (CFD) software FLUENT to simulate steady cavitating flow. At a fixed attack angle, pressure distributions and volume fractions of vapor at different cavitation numbers were simulated, and the results on foil sections agreed well with experimental data. In addition, at the various cavitation numbers, the vapor fractions at different attack angles were also predicted. The vapor region moved towards the front of the airfoil and the length of the cavity grew with increased attack angle. The results show that this method of applying FLUENT to simulate cavitation is reliable. 展开更多
关键词 2-d hydrofoil cavitation model cavitation flow
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Stabilization of Discrete-time 2-D T-S Fuzzy Systems Based on New Relaxed Conditions 被引量:2
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作者 XIE Xiang-Peng ZHANG Hua-Guang 《自动化学报》 EI CSCD 北大核心 2010年第2期267-273,共7页
This paper is concerned with the problem of stabilization of the Roesser type discrete-time nonlinear 2-D system that plays an important role in many practical applications. First, a discrete-time 2-D T-S fuzzy model ... This paper is concerned with the problem of stabilization of the Roesser type discrete-time nonlinear 2-D system that plays an important role in many practical applications. First, a discrete-time 2-D T-S fuzzy model is proposed to represent the underlying nonlinear 2-D system. Second, new quadratic stabilization conditions are proposed by applying relaxed quadratic stabilization technique for 2-D case. Third, for sake of further reducing conservatism, new non-quadratic stabilization conditions are also proposed by applying a new parameter-dependent Lyapunov function, matrix transformation technique, and relaxed technique for the underlying discrete-time 2-D T-S fuzzy system. Finally, a numerical example is provided to illustrate the effectiveness of the proposed results. 展开更多
关键词 Roesser model 2-d discrete systems Takagi-Sugeno (T-S) fuzzy model relaxed stabilization conditions
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Quasi-3D Numerical Simulation of Tidal Hydrodynamic Field 被引量:1
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作者 宋志尧 薛鸿超 +2 位作者 严以新 茅丽华 徐福敏 《China Ocean Engineering》 SCIE EI 1999年第3期265-276,共12页
Based on the 2D horizontal plane numerical model, a quasi-3D numerical model is established for coastal regions of shallow water. The characteristics of this model are that the velocity profiles;can be obtained at the... Based on the 2D horizontal plane numerical model, a quasi-3D numerical model is established for coastal regions of shallow water. The characteristics of this model are that the velocity profiles;can be obtained at the same time when the equations of the value of difference between the horizontal current velocity and its depth-averaged velocity in the vertical direction are solved and the results obtained are consistent with the results of the 2D, model. The circulating flow in the rectangular area induced by wind is simulated and applied to the tidal flow field of the radial sandbanks in the South Yellow Sea. The computational results from this quasi-3D model are in good agreement with analytical results and observed data. The solution of the finite difference equations has been found to be stable, and the model is simple, effective and practical. 展开更多
关键词 tidal hydrodynamic field quasi-3D numerical model 2D numerical model velocity profile numerical simulation
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Robust Non-Fragile Control of 2-D Discrete Uncertain Systems: An LMI Approach
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作者 Paramanand Sharma Amit Dhawan 《Journal of Signal and Information Processing》 2012年第3期377-381,共5页
This paper considers the problem of robust non-fragile control for a class of two-dimensional (2-D) discrete uncertain systems described by the Fornasini-Marchesini second local state-space (FMSLSS) model under contro... This paper considers the problem of robust non-fragile control for a class of two-dimensional (2-D) discrete uncertain systems described by the Fornasini-Marchesini second local state-space (FMSLSS) model under controller gain variations. The parameter uncertainty is assumed to be norm-bounded. The problem to be addressed is the design of non-fragile robust controllers via state feedback such that the resulting closed-loop system is asymptotically stable for all admissible parameter uncertainties and controller gain variations. A sufficient condition for the existence of such controllers is derived based on the linear matrix inequality (LMI) approach combined with the Lyapunov method. Finally, a numerical example is illustrated to show the contribution of the main result. 展开更多
关键词 2-d DISCRETE Systems Fornasini-Marchesini Second Local STATE-SPACE model NON-FRAGILE Control Linear Matrix INEQUALITY Lyapunov Methods
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LMI Approach to Suboptimal Guaranteed Cost Control for 2-D Discrete Uncertain Systems
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作者 Amit Dhawan Haranath Kar 《Journal of Signal and Information Processing》 2011年第4期292-300,共9页
This paper studies the problem of the guaranteed cost control via static-state feedback controllers for a class of two-dimensional (2-D) discrete systems described by the Fornasini-Marchesini second local state-space ... This paper studies the problem of the guaranteed cost control via static-state feedback controllers for a class of two-dimensional (2-D) discrete systems described by the Fornasini-Marchesini second local state-space (FMSLSS) model with norm bounded uncertainties. A convex optimization problem with linear matrix inequality (LMI) constraints is formulated to design the suboptimal guaranteed cost controller which ensures the quadratic stability of the closed-loop system and minimizes the associated closed-loop cost function. Application of the proposed controller design method is illustrated with the help of one example. 展开更多
关键词 Linear Matrix INEQUALITY Lyapunov Methods Robust Stability 2-d DISCRETE SYSTEMS Uncertain SYSTEMS Fornasini-Marchesini Second Local STATE-SPACE model
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Modelling,Validation,and Calculations of Stratospheric Ozone Dynamics and Latitudinal Changes 被引量:1
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作者 Ibraheem Alelmi Laurie Wei Sen Nieh 《Journal of Environmental Science and Engineering(B)》 2023年第6期265-279,共15页
This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions conside... This paper presents an engineering system approach of 2-D cylindrical model of mass balance calculations with convection,diffusion,and all potential photolysis,ozone generating and depleting chemical reactions considered.This model was developed,validated,and tested under different conditions for the stratospheric ozone.The calculated ozone concentrations and profile in the stratosphere at both the Equator and mid-latitudinal location of 40°S were found to exhibit a similar and close profile and peak value of the published measured data.The discrepancy between the calculations and measurements for the average ozone concentration was shown to be less than 1%and the variation of distributions to be less than 19%.The latitudinal changes of ozone concentrations,distribution,and peak of the layer were found to shift from 9.41 ppm at mid-altitude of z=30 km at the Equator,to 7.81 ppm at z=34.5 km at 40°S,to 5.78 ppm at higher altitude z=39 km at the South Pole.The total ozone abundances at strategic latitudes at 0°S,20°S,40°S,60°S,and 90°S,were found to remain stable and not much changed,from 305 DU to 335 DU,except a smaller value of 288 DU at the South Pole.The possible explanations of ozone profile change and peak shifting as affected by solar/UV radiation,latitudinal locations,and ozone-depleting reactions were discussed and elaborated.The 2-D ozone Model presented in this paper is a robust,efficient,executable,and validated model for studying the complex ozone phenomena in the stratosphere. 展开更多
关键词 2-d ozone model stratospheric ozone validation ozone depletion latitudinal changes
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Analytical model of non-uniform charge distribution within the gated region of GaN HEMTs
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作者 Amgad A.Al-Saman Eugeny A.Ryndin +2 位作者 Xinchuan Zhang Yi Pei Fujiang Lin 《Journal of Semiconductors》 EI CAS CSCD 2023年第8期87-93,共7页
A physics-based analytical expression that predicts the charge,electrical field and potential distributions along the gated region of the GaN HEMT channel has been developed.Unlike the gradual channel approximation(GC... A physics-based analytical expression that predicts the charge,electrical field and potential distributions along the gated region of the GaN HEMT channel has been developed.Unlike the gradual channel approximation(GCA),the proposed model considers the non-uniform variation of the concentration under the gated region as a function of terminal applied volt-ages.In addition,the model can capture the influence of mobility and channel temperature on the charge distribution trend.The comparison with the hydrodynamic(HD)numerical simulation showed a high agreement of the proposed model with numerical data for different bias conditions considering the self-heating and quantization of the electron concentration.The ana-lytical nature of the model allows us to reduce the computational and time cost of the simulation.Also,it can be used as a core expression to develop a complete physics-based transistorⅣmodel without GCA limitation. 展开更多
关键词 AlGaN/GaN(HEMTs) 2DEG charge distribution electron mobility hydrodynamic model channel temperature
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A 2-D HYDRODYNAMIC MODEL FOR THE RIVER,LAKE AND NETWORK SYSTEM IN THE JINGJIANG REACH ON THE UNSTRUCTURED QUADRANGLES 被引量:5
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作者 ZHANG Xi-bing HU De-chao WANG Min 《Journal of Hydrodynamics》 SCIE EI CSCD 2010年第3期419-429,共11页
The main river, the Dongting Lake and river networks in the Jingjiang reach of the Yangtze River constitute a complex water system, for which a full 2-D hydrodynamic model is established instead of the traditional 1-D... The main river, the Dongting Lake and river networks in the Jingjiang reach of the Yangtze River constitute a complex water system, for which a full 2-D hydrodynamic model is established instead of the traditional 1-D or compound models for simulation of such complex systems, based on the latest developments of computer technologies and numerical methods. To better handle irregular boundaries and keep the computation cost well in a reasonable limit, unstructured grids of moderate scale are used. In addition, a dynamic boundary tracking method is proposed to simulate variable flow domains at different floods, especially, when the moderate scale gird can not describe flows in narrow river-network channels at low water levels. The t9 semi-implicit method and the Eulerian-Lagrangian Method (ELM) are adopted, which make the model unconditionally stable with respect to the gravity wave speed and Courant number restrictions. Properties and efficiency of the model are discussed, and it is concluded that the new model is robust and efficient enough for the simulation of a big, complex water system. Validation tests show that the simulation results agree well with field data. It takes about 0.96 h to complete the computation of a 76 d flood, which indicates that the model is efficient enough for engineering applications. 展开更多
关键词 2-d numerical model river network unstructured grid SEMI-IMPLICIT Eulerian-Lagrangian Method (ELM) boundarytracking
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ONE-AND TWO-DIMENSIONAL COUPLED HYDRODYNAMICS MODEL FOR DAM BREAK FLOW 被引量:8
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作者 YANG Fang-li ZHANG Xiao-feng TAN Guang-ming 《Journal of Hydrodynamics》 SCIE EI CSCD 2007年第6期769-775,共7页
1-D and 2-D mathematical models for dam break flow were established and verified with the measured data in laboratory. The 1-D and 2-D models were then coupled, and used to simulate the dam break flow from the reservo... 1-D and 2-D mathematical models for dam break flow were established and verified with the measured data in laboratory. The 1-D and 2-D models were then coupled, and used to simulate the dam break flow from the reservoir tail to the dam site, the propagation of dam break waves in the downstream channel, and the submergence of dam break flow in the downstream town with the hydrodynamics method. As a numerical example, the presented model was employed to simulate dam break flow of a hydropower station under construction. In simulation, different dam-break durations, upstream flows and water levels in front of dam were considered, and these influencing factors of dam break flow were analyzed, which could be referenced in planning and designing hydropower stations. 展开更多
关键词 dam-break flow hydrodynamics model 1-d and 2-d coupled model dam-break duration upstream flow water level before dam
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