State of the Art Two- Dimensional Hydraulic Modeling Tools Model Benchmark Testing

Transcription

1 State of the Art Two- Dimensional Hydraulic Modeling Tools Model Benchmark Testing September 2015 Presented by: Murari Paudel, Cody Milligan, Soledad Roman, Phillip Ryan

2 Presentation Overview Study Purpose Methodology and Limitations Test Cases Assessment Results Conclusions

3 Study Purpose Benchmark TUFLOW (2013), MIKE21 (2014) and HECRAS 5.0 (March 2015) Test the models for a range of basic hydraulic conditions and model performance measures: 1. Hydraulic losses: Does the model scheme account for losses accurately? 2. Grid convergence: Does the model produce similar result for a range of cell sizes? 3. Simulation run time: How efficient is the model s solution scheme?

4 Methodology Create 3 simple test cases 1. Channel bend 2. Constriction 3. Flat bed (flood propagation) Run simulations for a range of flow conditions and cell sizes Number of scenarios = 109 Assess model results against measured data 1 2 3

5 Test Case Bend Loss Aim: verify models estimate losses resulting from an abrupt bend accurately Validate against laboratory experiment (Malone 2008)

6 Test Case Bend Loss Empirical equations from laboratory results

7 Bend Model Configuration Scaled to match dimensions of laboratory test 0, 45 and 90 degree scenarios. 15ft grid resolution. Free overfall conditions downstream boundary Inflow Boundary Downstream Boundary

8 Bend Model Configuration Scaled to match dimensions of laboratory test 0, 45 and 90 degree scenarios. 5 flow scenarios. 15ft grid resolution. Downstream boundary free overfall conditions Output Location P1 Output Location P2

9 Result: HECRAS5.0 (Full Momentum)

10 Result: MIKE21

11 Result: TUFLOW

12 Bend Test Result Summary All models produced reasonable results MIKE21 and HECRAS 5.0 resulted in slightly greater head loss due to bend TUFLOW resulted in slightly smaller loss at 90 bend and slightly more at 45 Runtime Efficiency HECRAS 5.0 (FM) = 2 minutes 36 second (8 Processors) MIKE 21 = 1 minute 23 seconds (8 Processors) TUFLOW = 2 minutes 13 seconds (1 Processor)

13 Test Case Constriction Aim: verify models estimate losses resulting from a constriction (eg. bridge abutments) Aim: assess grid convergence in model results Validated against Federal Highways Administration Equations (Bradley, 1978)

14 Constriction Model Configuration 40% opening width in a uniform rectangular channel 10ft and 30ft grid resolution. 3 flow scenarios. Free overfall conditions downstream boundary 90ft 120ft 90ft Inflow Boundary Downstream Boundary

15 Result: HECRAS5.0 (Diffusive Wave)

16 Result: HECRAS5.0 (Full Momentum)

17 Result: MIKE21 10ft Resolution, 3000cfs

18 Result: TUFLOW 10ft Resolution, 3000cfs

19 Constriction Test Result Summary Grid size convergence HECRAS 5.0 Full momentum, Mike21 and TUFLOW produced reasonable results HECRAS 5.0 and Mike21 produced slightly higher loss while TUFLOW produced slightly smaller loss HECRAS 5.0 Diffusion wave showed inconsistency Runtime Efficiency (10ft resolution) HECRAS 5.0 (DW) = 3 min 4 sec (8 Processors) HECRAS 5.0 (FM) = 4 min 34 sec (8 Processors) MIKE 21 = 1min 29 seconds (8 Processors) TUFLOW = 2min 3 seconds (1 Processor)

20 Test Case Speed of flood propagation Based on UK EPA benchmark test Aim: test is to assess the package s ability to simulate the celerity of propagation of a flood wave and predict transient velocities and depths. Aim: Compare model simulation run time The model scenario size has been increased from UK version to make a better estimate of the model simulation time (50,000 cells)

21 Flood propagation Model Configuration Flat bed 4000m 20m grid resolution 20m 3 /s inflow through a 20m opening 24hr simulation period Inflow Boundary P1 P2 8000m

22 Result: Water Level

23 Result: Velocity

24 Result: Wave Propagation

25 Result: Simulation Time Simulation Time Model HECRAS 5.0 MIKE21 TUFLOW Simulation Time 20m 27minutes 53 sec 7 minutes 3 seconds 56 seconds

26 Conclusions Model Results? Channel Bend Loss All three software produce relatively similar results HECRAS 5.0 and MIKE21 marginally overestimate the head loss TUFLOW is marginally underestimating Channel Constriction Consistent results across all the three software HECRAS 5.0 and MIKE21 produced head loss slightly higher TUFLOW is marginally underestimating Wave Propagation All the three software show consistent results, timing, depth and velocity Significant difference in the model run times HEC-RAS Diffusive wave Use with caution Model Simulation Times? MIKE21 and TUFLOW similar. HECRAS 5.0 relatively slower Parallel processing vs parallel simulations? Other factors?

27 Thank You Murari Paudel, PhD, CFM Wood Rodgers Inc. (916)