new features for hec-ras 5.0.4+ · 2018-09-24 · erosion model (bstem) 3. other new sediment...
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New Features for HEC-RAS 5.0.4+
Martin Teal, P.E., P.H., D.WRE
September 4, 2018
Thanks to HEC Staff:• Stanford Gibson, Ph.D.• Alex Sánchez, Ph.D.
2017 Topics – 5.0 to 5.0.3+
1. Unsteady Sediment Transport
2. USDA-ARS Bank Stability and ToeErosion Model (BSTEM)
3. Other New Sediment Features
2018 Topics – 5.0.3 to 5.0.5+
1. Transport Function Calibration / Modification
2. Variable Sediment Properties3. 2D Connection4. Internal Stage BC (Quasi-
Unsteady)5. Sediment Rules
2018 Topics – 5.1+
1. 2D Sediment Transport
3. Stochastic Sediment (WAT)4. New Viewer
2. Non-Newtonian Flow
REMINDER - Develop and Calibrate a Good Hydraulic Model First
-Variable n-values-Ineffective Flow Areas
HEC-RAS Sediment Data InputStarts here:
2018 Topics – 5.0.3 to 5.0.5+
1. Transport Function Calibration / Modification
2. Variable Sediment Properties3. 2D Connection4. Internal Stage BC (Quasi-
Unsteady)5. Sediment Rules
Transport Function Calibration / Modification1. “Exposes”
transport parameters
2. Two ratios added for calibration
Variable Sediment Properties1. Editor expanded to include other
properties
2. Allows gaps and overlaps in grain size properties (check box)
2D Sediment Connection
1. Passes sediment from unsteady 1D model to a 2D area using a lateral structure
2. Since no 2D sediment (yet), simply becomes a sink
Internal Stage Boundary Condition1. Quasi-unsteady enhancement
2. ISBC – time series of fixed stages at any X-Sec
a. Overrides TS Gate Openings
b. Useful in dam removal / flushing
Sediment Rules1. RAS can operate structures based on
bed change at a cross section or sediment concentration (e.g., downstream TMDLs).
2018 Topics – 5.1+
1. 2D Sediment Transport
3. Stochastic Sediment (WAT)4. New Viewer
2. Non-Newtonian Flow
2D Sediment TransportCo-development for RAS & HMSFinite Volume:
Mass conservativeUnstructured polygonal mesh:
Maximum flexibilityImplicit:
Robust for large time stepsDetailed subgrid bathymetry
Partial wetting and drying Allows for much larger cells while maintaining
accuracy
Subgrid Modeling
Rain
Channel
Percolation
Computational Cell
Wet Dry
• Representation of the physical terrain and processes at a subgrid scale
• Allows for larger grid cells reducing computational cells, and computational times
Subgrid Modeling
Hydrodynamics
Ele
vatio
n
Area
Ele
vatio
n
Volume
Subgrid Modeling
Flow
Sediment
ElevationArea
Elevation
Area
Elevation
Area
Elevation
Area
0 50 100 150 200 250-5.5
-5
-4.5
-4
-3.5
-3
-2.5
-2
-1.5
Time step
Ele
vatio
n, m
Bed Layering Example
2D Prototype Model Validation
Bed
Cha
nge
(ft)
Cur
rent
Vel
ocity
(m/s
)C
once
ntra
tion
(mg/
L)
Elev
atio
n (ft
)
Fargo Model From MVP
HEC contacted several districts to find promising 2D validation data sets on the prototype scale and are acquiring data from MVS and NWP.
2D Prototype Model Validation
Non-Newtonian FlowFlow Type ModelHyperconcentrated Bingham PlasticMudflow Quadratic (Turbulent)Debris Flow Quadratic (Turbulent + Dispersive)
Stochastic Sediment with HEC-RAS and HEC-WAT
New 5.1 Sediment Results Viewer
Questions?
Holtwood Dam, September 10, 2011 (TheGates1210 on YouTube)
Bank-Bed Scour CalibrationHEC-RAS/BSTEM Model
of Missouri River D/S of Gavins Point Dam
BSTEM
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