Calibration (under increasing complexity)

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Against the background of the 2km x 30Ha Levisham hydraulic analysis – here –  the table below lists 2D models run to assess the productivity of finite element meshes derived from assembled point clouds of increasing complexity.  Denser point clouds are tested towards a productivity goal of 30,000 CFD nodes solved in real time x 3  (ie:  a 15 minute time-series fed to a 500ha x 20node/ha floodplain & solved to 1% convergence in 5 minutes) .

References:  OS map here,  relief map here, and animation here

Model	km x Ha	In-Flow	Tributaries	Out-Flow	Graphics
pk2a1	12 x 160	3 @ 67.0	none	Q=0.07H^1.8	Here
pk2a4
pk2b6
pk2b7

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Column Heading Legend

• Model filename: ‘pk’=pickering; ‘2’=12km reach; ‘a,b’=configuration; ‘1’=build
• Footprint: River length (km) and ‘Q-T200’ wet area (ha)
• In-flow discharge characteristics: m3/s x water surface level aod
• Tributary discharge inflow (m3/s)
• Out-flow discharge relationship : H=stage; k & m parameters of flume equation Q = kH^m
• Graphic: Click for illustrations relating to hydraulic models

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Models

a. Steady Flow; Main channel only; Vee discharge in; Flume discharge out

pk2a1  4000 node point cloud budget;  elevation data resampled from various sources; Productivity goal = 24hr hydrograph in 50mins @ 3% convergence tolerance; vee-form bed; build 1 canalises the flow to test boundary flumes;  tributaries and friction features excluded; TIN points from ‘risk’ buffer  GIS lines below;

1. River centreline resampled @ 16m to 760 nodes; elevation from smoothed radar minus 3m
2. Tributary centrelines resampled @ 16m; elevation also from smoothed radar minus 3m
3. Flumes :  Inflow (North, Levisham) and outflow (South, Ropery Br) built relative to first & last c/line points and outwith the boundary of terrain elements
4. LR (LeftRight) banklines; buffer=4m; excluded from this CFD mesh
5. LR bermlines; buffer=8m; resampled @ 16m to 1520 nodes; elev=radar+3
6. LR Q24lines; buffer=24m; resampled @ 32m to 760 nodes; elev=radar+3
7. LR Q40lines; buffer=40m; resampled @ 64m to 276 nodes; elev=radar+3
8. LR Q100lines; buffer=50m; resampled @ 50m to 380 nodes; elev=radar

File structure for River 2D terrain TIN and CFD Mesh

For TIN (.bed) file in R2D assemble in 5 cols excel; counter-clockwise bdy pts first,  delimited by [pts }; flumes and perimeter points last; Triangulate; add breaklines (brackets or GUI);  rename and adjust flume pts on boundary save as .bed file from R2D_bed app; open in notepad++ and delete list defining bdy pts as breakline pts; check for extra points and rename; make high and low friction versions nb: nodes. then breaklines. then boundary. perimeter points (which surround bdy pts) always after last node

For CFD (.msh) file in R2D copy .bed point assy move bdy cols one row to the right and insert x col move bdy rows UP and insert below last node (ie above “no more breaklines.” remove perimeter points   Top

Location Map

Pickering Beck

 

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