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1D Unsteady Flow
This is a course that applies HEC-RAS for One-Dimensional Unsteady Flow Modeling. The course provides participants with the knowledge to effectively use HEC-RAS to model and analyze hydraulic conditions in natural and constructed channels, utilizing one-dimensional unsteady flow hydraulics
Topics covered in this course are listed below.
- Overview of Unsteady Flow Modeling and Example Applications
- Introduction to the Unsteady Flow Equations
- Geometric Data Pre-processing
- Description and Uses of Boundary Conditions and Initial Conditions
- Accessing and Utilizing Model Output in HEC-RAS and RAS Mapper
- Modeling Bridges Inline Structures, Lateral Structures and Storage Areas
- Calibration of Unsteady Flow Models
- Detecting and Fixing Common Model Stability Problems
- Advanced Features in HEC-RAS
- Introduction to Dam and Levee Breach Modeling
- Introduction to Rules for Controlling Structures
Prerequisites
Participants must have a good background in open channel hydraulics and be familiar with the HEC-RAS software. Basic HEC-RAS model development and input and output data requirements will not be covered in this class. It will be assumed that you already know how to use the software for performing a steady flow analysis. Familiarity with the unsteady flow equations and numerical solution techniques is desirable. Participants should be in positions requiring them to perform complex hydraulic analysis.
Instructors:
Stanford Gibson (Course Coordinator)
Mark Jensen
Cameron Ackerman
Eric Tichansky
Alex Sanchez
Alex Kennedy
Chris Nygaard
Class Materials
Terms of Use
Any use or reproduction of this material must be attributed to the US Army Corps of Engineers Hydrologic Engineering Center.
Day 1
| Time | Topic | Objective | Instructor | Material | |
|---|---|---|---|---|---|
| 0800-0900 | L0 | Introductions and Pre-Course Activities | Welcome and discussion of class expectations | Gibson | |
| 0900-945 | L1.1 | Overview of Unsteady Flow Modeling | Description of unsteady flow applications (why would you use it). Distinction between steady and unsteady flow and hydrologic/hydraulic routing. Demonstration of unsteady flow. | Gibson | |
| 945-1015 | W1.2 | Guided Demonstration | Guided exploration of example unsteady applications | Gibson | - |
| 1015-1030 | Break | ||||
| 1030-1130 | L1.3 | River Hydraulics and Intro to Unsteady Flow Equations | Introduction to the unsteady flow equations and solution techniques and a description of the computational differences between steady and unsteady flow. | Jensen | |
| 1130-1230 | Lunch | ||||
| 1230-1330 | L1.4 | Data Requirements for 1D Unsteady Geometry | Types of data required, sources and availability. Limitations and flexibility of HEC-RAS with regard to data. Focus on preparing geometric data (cross sections) and processing that data with the HEC-RAS Pre-Processor (HTAB). | Ackerman | |
| 1330-1445 | W1.5 | Pre-Processing Geometric Data | This workshop will guide students to set cross-sectional table properties; pre-process the cross sections into tables of elevation versus conveyance, area, and storage; and to review and interpret the results from the pre-processor. | Ackerman, Jensen | |
| 1500-1515 | Break | ||||
| 1515-1545 | Review | Ackerman | |||
| 1545-1630 | L2.1 | Overview of Model Output | Overview of available output from unsteady flow modeling. Discussions of optional output and how to obtain it. | Tichansky | |
| 1630-1700 | Quiz Game Review | www.kahoot.it | Gibson |
Day 2
| Time | Topic | Objective | Instructor | Material | |
|---|---|---|---|---|---|
| 0800-0845 | L1.6 | Boundaries and Initial Conditions | Description of the various types of unsteady flow boundary conditions needed and available within HEC-RAS. Discussion of initial conditions and how to establish them. | Sanchez | |
| 0845-0930 | L2.2 | HEC-RAS Mapper Introduction | RAS Mapper Introduction with focus on reviewing 1D results | Kennedy | |
| 0915-0930 | Break | ||||
| 0930-1115 | W2.3 | Basic Unsteady Flow Modeling and Reviewing Results | Students will learn how enter the necessary data; run the pre-processor, perform the unsteady flow calculations, review the results of an unsteady flow model, and explore RAS Mapper capabilities. | Sanchez, Tichansky | |
| 1115-1145 | Review | Sanchez | |||
| 1145-1245 | Lunch | ||||
| 1245-1345 | L2.4 | Modeling Bridges and Culverts | Overview of input data for bridges and culverts. Entering hydraulic table parameters for bridges and culverts. Reviewing pre-processor output and unsteady flow output for bridges and culverts. | Ackerman | |
| 1345-1545 | W2.5 | Modeling Bridges | Overview of input data for bridges and culverts. Entering hydraulic table parameters for bridges and culverts. Reviewing pre-processor output and unsteady flow output for bridges and culverts. | Ackerman, Gibson | |
| 1545-1600 | Break | ||||
| 1600-1630 | Review | Ackerman | |||
| 1630-1700 | Quiz Game Review | Gibson |
Day 3
| Time | Topic | Objective | Instructor | Material | |
|---|---|---|---|---|---|
| 0800-0900 | L3.1 | Inline and Lateral Structures | Discussions of modeling inline and lateral hydraulic structures. Entering spillway and weir data, lateral culverts, and rating curves. Connecting lateral structures to storage areas and other reaches. Controlling gate settings. Reviewing output for inline and lateral structures. | Tichansky | |
| 0900-0945 | L3.2 | Storage Areas and Storage Area Connections | The purpose of storage areas and how to model with them. Connecting storage areas to other storage areas using storage area connections. Input and output for storage areas and storage area connections. | Nygaard/ Gibson | |
| 0945-1000 | Break | ||||
| 1000-1130 | W3.3 | Lateral Structures, Storage Areas and Storage Area Connections | Students will learn how to create and use lateral structures, storage areas. and storage area connections to model off-channel storage in the overbanks. Students will learn how to connect storage areas to river reaches and other storage areas using Storage Area Connections | Nygaard/ Gibson Tichansky | |
| 1130-1230 | Lunch | ||||
| 1230-1300 | W3.3 | Lateral Structures, Storage Areas and Storage Area Connections (continued) | Students will learn how to create and use lateral structures, storage areas. and storage area connections to model off-channel storage in the overbanks. Students will learn how to connect storage areas to river reaches and other storage areas using Storage Area Connections | Nygaard/ Gibson Tichansky | |
1300-1330 | Review | Nygaard/ Gibson | |||
| 1330-1430 | L3.4 | Calibration of Unsteady Flow Models | Interpretation, use, and reliability of field data. Which parameters to calibrate and adjust, problems and solutions. Calibration for large alluvial streams | Jensen | |
| 1430-1445 | Break | ||||
| 1445-1630 | W3.5 | Calibration of the Mississippi - Ohio Confluence | Students will learn how to adjust model parameters to replicate water surface elevations, discharges, and travel times. | Jensen, Tichansky | |
| 1630-1645 | Review Quiz Games |
Day 4
| Time | Topic | Objective | Instructor | Material | |
|---|---|---|---|---|---|
| 0800-0830 | Review | Jensen | |||
| 0830-0945 | L4.1 | Common Model Stability Problems | Cross-section spacing. Selection of model computational time step. Controlling iterations, tolerances, and other model stability factors. Understanding model sensitivity and the parameters that are most significant. | Jensen | |
| 0945-1000 | Break | ||||
| 1000-1045 | L4.2 | Detecting and Fixing Stability Problems | Detecting stability problems. Discussions will include how to turn on and review detailed log output from the unsteady flow model run. | Jensen | |
| 1045-1145 | W4.3 | Troubleshooting Workshop | Students will learn to detect and resolve several types of model instability problems. | Jensen, Ackerman | |
| 1145-1245 | Lunch | ||||
| 1245-1415 | W4.3 | Troubleshooting Workshop (continued) | Jensen, Ackerman | ||
| 1415-1430 | Break | ||||
| 1430-1500 | L4.4a | Advanced Features | Mixed Flow, Modified Puls, Finite Volume, Pipe Flow | Nygaard | |
| 1500-1530 | L4.4b | Dam and Levee Breach | Dam and levee breach modeling. | Gibson | |
| 1530-1700 | W4.5 | Dam and Levee Breach Workshop | Students will learn how to use HEC-RAS to perform a dam breaching analysis, as well as a levee breaching analysis. | Gibson, Tichansky |
Day 5
| Time | Topic | Objective | Instructor | Material | |
|---|---|---|---|---|---|
| 0800-0830 | Review | Gibson | |||
| 0830-0900 | L5.1 | Introduction to the Rules Editor | This lecture will introduce students to using the rules editor for controlling gates at Inline and lateral structures, as well as storage area connections. Other uses for the rules editor will also be introduced. | Gibson | |
| 0900-0915 | Break | ||||
| 0915-1015 | W5.2 | Rules Editor Guided Demonstration | A student interactive demonstration of the use of rules will be given. | Gibson | |
| 1015-1030 | Final Review Quiz Game | ||||
| 1030-1130 | Post Test, Course Feedback | Gibson |