The Experts below are selected from a list of 3501 Experts worldwide ranked by ideXlab platform
Gary D Doolen - One of the best experts on this subject based on the ideXlab platform.
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lattice boltzmann method on a Curvilinear Coordinate system vortex shedding behind a circular cylinder
Physical Review E, 1997Co-Authors: Gary D DoolenAbstract:The interpolation-supplemented lattice Boltzmann equation (ISLBE) method is used to simulate the two-dimensional vortex shedding behind a circular cylinder at low Reynolds numbers. Simulations are carried out on a polar-Coordinate grid system with a dense grid distributed near the cylinder surface. The Strouhal number, the drag, and the lift coefficients obtained from the simulations agree well with previous experimental measurements and classical computational fluid dynamics simulations. Comparisons of detailed flow patterns with other studies via streamlines and streaklines are also satisfactory. The ability of the ISLBE scheme to simulate complicated long-term periodic flow phenomena is demonstrated.
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lattice boltzmann method on a Curvilinear Coordinate system vortex shedding behind a circular cylinder
Physical Review E, 1997Co-Authors: Gary D DoolenAbstract:The interpolation-supplemented lattice Boltzmann equation (ISLBE) method is used to simulate the two-dimensional vortex shedding behind a circular cylinder at low Reynolds numbers. Simulations are carried out on a polar-Coordinate grid system with a dense grid distributed near the cylinder surface. The Strouhal number, the drag, and the lift coefficients obtained from the simulations agree well with previous experimental measurements and classical computational fluid dynamics simulations. Comparisons of detailed flow patterns with other studies via streamlines and streaklines are also satisfactory. The ability of the ISLBE scheme to simulate complicated long-term periodic flow phenomena is demonstrated. {copyright} {ital 1997} {ital The American Physical Society}
Ran Bin - One of the best experts on this subject based on the ideXlab platform.
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Infrastructure Assisted Constrained Connected Automated Vehicle Trajectory Optimization on Curved Roads: A Spatial Formulation on a Curvilinear Coordinate
2021Co-Authors: Yi Ran, Zhou Yang, Wang Xin, Liu Zhiyuan, Li Xiaotian, Ran BinAbstract:Vehicle trajectory optimization is essential to ensure vehicles travel efficiently and safely. This paper presents an infrastructure assisted constrained connected automated vehicles (CAVs) trajectory optimization method on curved roads. This paper systematically formulates the problem based on a Curvilinear Coordinate which is flexible to model complex road geometries. Further, to deal with the spatial varying road obstacles, traffic regulations, and geometric characteristics, two-dimensional vehicle kinematics is given in a spatial formulation with exact road information provided by the infrastructure. Consequently, we applied a multi-objective model predictive control (MPC) approach to optimize the trajectories in a rolling horizon while satisfying the collision avoidances and vehicle kinematics constraints. To verify the efficiency of our method, a numerical simulation is conducted. As the results suggest, the proposed method can provide smooth vehicular trajectories, avoid road obstacles, and simultaneously follow traffic regulations, which is robust to road geometries and disturbances
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Infrastructure Assisted Constrained Connected Automated Vehicle Trajectory Optimization on Curved Roads: A Spatial Formulation on a Curvilinear Coordinate
2021Co-Authors: Yi Ran, Zhou Yang, Wang Xin, Liu Zhiyuan, Li Xiaotian, Ran BinAbstract:Vehicle trajectory optimization is essential to ensure vehicles travel efficiently and safely. This paper presents an infrastructure assisted constrained connected automated vehicles (CAVs) trajectory optimization method on curved roads. This paper systematically formulates the problem based on a Curvilinear Coordinate which is flexible to model complex road geometries. Further, to deal with the spatial varying road obstacles, traffic regulations, and geometric characteristics, two-dimensional vehicle kinematics is given in a spatial formulation with exact road information provided by the infrastructure. Consequently, we applied a multi-objective model predictive control (MPC) approach to optimize the trajectories in a rolling horizon while satisfying the collision avoidances and vehicle kinematics constraints. To verify the efficiency of our method, a numerical simulation is conducted. As the results suggest, the proposed method can provide smooth vehicular trajectories, avoid road obstacles, and simultaneously follow traffic regulations, which is robust to road geometries and disturbances.Comment: Needs some more systematic revision
Dan Quinlan - One of the best experts on this subject based on the ideXlab platform.
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AMR++: Object-Oriented Parallel Adaptive Mesh Refinement AMR++: Object-Oriented Parallel Adaptive Mesh Refinement
2020Co-Authors: D 5 Philip, Bobby Philip, Dan QuinlanAbstract:Abstract Adaptive mesh refinement (AMR) computations are complicated by their dynamic nature. The development of solvers for realistic applications is complicated by both the complexity of the AMR and the geometry of realistic problem domains. The additional complexity of distributed memory parallelism within such AMR applications most commonly exceeds the level of complexity that can be reasonable maintained with traditional approaches toward software development. This paper will present the details of our object-oriented work on the simplification of the use of adaptive mesh refinement on applications with complex geometries for both serial and distributed memory parallel computation. We will present an independent set of object-oriented abstractions (C++ libraries) well suited to the development of such seemingly intractable scientific computations. As an example of the use of this object-oriented approach we will present recent results of an application modeling fluid flow in the eye. Within this example, the geometry is too complicated for a single Curvilinear Coordinate grid and so a set of overlapping Curvilinear Coordinate grids' are used. Adaptive mesh refinement and the required grid generation work to support the refinement process is coupled together in the solution of essentially elliptic equations within this domain. This paper will focus on the management of complexity within development of the AMR++ library which forms a part of the Overture object-oriented framework" for the solution of partial differential equations within scientific computing
Thomas R. Bewley - One of the best experts on this subject based on the ideXlab platform.
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on the contravariant form of the navier stokes equations in time dependent Curvilinear Coordinate systems
Journal of Computational Physics, 2004Co-Authors: Thomas R. BewleyAbstract:The contravariant form of the Navier-Stokes equations in a fixed Curvilinear Coordinate system is well known. However, when the Curvilinear Coordinate system is time-varying, such as when a body-fitted grid is used to compute the flow over a compliant surface, considerable care is needed to handle the momentum term correctly. The present paper derives the complete contravariant form of the Navier-Stokes equations in a time-dependent Curvilinear Coordinate system from the intrinsic derivative of contravariant vectors in a moving frame. The result is verified via direct transformation. These complete equations are then applied to compute incompressible flow in a 2D channel with prescribed boundary motion, and the significant effect of some terms which are sometimes either overlooked or assumed to be negligible in such a derivation is quantified.
Zhang Yang - One of the best experts on this subject based on the ideXlab platform.
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boussinesq equations in orthogonal Curvilinear Coordinate system
Marine Environmental Science, 2007Co-Authors: Zhang YangAbstract:In this paper,based on the mass conservation and Euler's equation,the modified form of Boussinesq equations is derived,which includes the effects of bottom friction,wave breaking and subgrid turbulent mixing.Through transferring the governing equation and boundary condition by the orthogonal Curvilinear Coordinate,a 2D wave model in the orthogonal Curvilinear Coordinate systems is established.The numerical model is tested by the computing wave field for several experimental terrains,and agreement between the model results and available experimental data is found to be quite reasonable.It demonstrates that the model is able to simulate wave shoaling,refraction,diffraction and reflection et al.
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research on boussinesq equations in orthogonal Curvilinear Coordinate system
Science & Technology Review, 2006Co-Authors: Zhang YangAbstract:In this paper, based on the mass conservation equation and Euler's equation, the modified form of Boussinesq equations is derived, which includes the effects of bottom friction, wave breaking and subgrid turbulent mixing. Through transferring the governing equations and boundary condition by orthogonal Curvilinear Coordinate, a 2D wave model in orthogonal Curvilinear Coordinate systems is established. The numerical model is tested by computing wave field for several experiment terrain, and agreement between model results and available experimental data is found to be quite reasonable, which demonstrates the model's ability to simulate wave shoaling, refraction, diffraction and reflection et etc.
