Computational grid, subgrid, and pixels

被引:20
作者
Casulli, Vincenzo [1 ]
机构
[1] Univ Trento, Dept Civil Environm & Mech Engn, Lab Appl Math, Via Mesiano 77, I-38123 Trento, Italy
关键词
cross-flow; free surface; grid cloning; semi-implicit; shallow water; subgrid; FREE-SURFACE FLOWS; FINITE-DIFFERENCE METHODS; SEMIIMPLICIT METHOD; ITERATIVE SOLUTION; MODEL; SCHEME; RIVER;
D O I
10.1002/fld.4715
中图分类号
TP39 [计算机的应用];
学科分类号
081203 ; 0835 ;
摘要
Free-surface flows in rivers, estuaries, and coastal areas are strongly dominated by the geometrical details of the study area. Nowadays, accurate bathymetric data are easily available on raster-based digital elevation models with an impressive spatial resolution. These data are often accessible as large two-dimensional arrays containing several millions of pixel values. Recent numerical methods are very efficient and rather accurate but far from being able to solve the governing differential equations on a computational grid with such a fine spatial resolution. In the present investigation, the unaltered pixel values from a digital elevation model are clustered to form subgrids of a coarser computational grid. Artificial cross-flow between disconnected areas is inhibited by introducing cell clones and edge clones. Each clone consists of directly connected pixels. It is shown how the resulting computational grid is able to resolve geometrical details of complex study areas to pixel resolution and for any grid size. As an example, the performance of the proposed algorithm is tested to simulate a typical tidal flow in the San Francisco Bay and the Sacramento-San Joaquin Delta area by using an extreme subgrid resolution given by a digital elevation model containing 196000000 pixels with 10m pixel size.
引用
收藏
页码:140 / 155
页数:16
相关论文
共 48 条
[1]   Modeling salt intrusion in the San Francisco Estuary prior to anthropogenic influence [J].
Andrews, S. W. ;
Gross, E. S. ;
Hutton, P. H. .
CONTINENTAL SHELF RESEARCH, 2017, 146 :58-81
[2]  
Bever A.J., 2016, San Francisco Estuary and Watershed Science, V14, P1, DOI [10/gkm465, DOI 10.15447/SFEWS.2016V14ISS1ART3]
[3]   Influence of an Observed Decadal Decline in Wind Speed on Turbidity in the San Francisco Estuary [J].
Bever, Aaron J. ;
MacWilliams, Michael L. ;
Fullerton, David K. .
ESTUARIES AND COASTS, 2018, 41 (07) :1943-1967
[4]   Factors influencing the calculation of periodic secondary circulation in a tidal river: numerical modelling of the lower Sacramento River, USA [J].
Bever, Aaron J. ;
MacWilliams, Michael L. .
HYDROLOGICAL PROCESSES, 2016, 30 (07) :995-1016
[5]   A semi-implicit scheme for 3D free surface flows with high-order velocity reconstruction on unstructured Voronoi meshes [J].
Boscheri, W. ;
Dumbser, M. ;
Righetti, M. .
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, 2013, 72 (06) :607-631
[6]   ITERATIVE SOLUTION OF PIECEWISE LINEAR SYSTEMS [J].
Brugnano, Luigi ;
Casulli, Vincenzo .
SIAM JOURNAL ON SCIENTIFIC COMPUTING, 2008, 30 (01) :463-472
[7]   ITERATIVE SOLUTION OF PIECEWISE LINEAR SYSTEMS AND APPLICATIONS TO FLOWS IN POROUS MEDIA [J].
Brugnano, Luigi ;
Casulli, Vincenzo .
SIAM JOURNAL ON SCIENTIFIC COMPUTING, 2009, 31 (03) :1858-1873
[8]   Semi-implicit numerical modeling of nonhydrostatic free-surface flows for environmental problems [J].
Casulli, V ;
Zanolli, P .
MATHEMATICAL AND COMPUTER MODELLING, 2002, 36 (9-10) :1131-1149
[9]   High resolution methods for multidimensional advection-diffusion problems in free-surface hydrodynamics [J].
Casulli, V ;
Zanolli, P .
OCEAN MODELLING, 2005, 10 (1-2) :137-151
[10]  
Casulli V, 2000, INT J NUMER METH FL, V32, P331, DOI 10.1002/(SICI)1097-0363(20000215)32:3<331::AID-FLD941>3.0.CO