THT211 Open Channel Flow

The course provides an introduction to the physical principles of flow in rivers, open channels and partially filled pipes, and demonstrates how these principles are used in typical engineering applications and in hydraulic software (HEC-RAS, HY-8, SWMM). The aim is that the students can carry out the most common engineering analyzes manually (by hand with calculator or in Excel/Python) or using hydraulic software, and can critically assess the analyzes and results. The course also contains a minor laboratory component. The course is primarily aimed at students enrolled in the study program in water and environmental engineering, but may also be relevant for other engineering students and students at the MINA-faculty.

The course consists of three main parts with the following content:

• Steady one-dimensional flow:
  • Introduction, basic concepts, review of the principles of flow in completely filled pipes.
  • Conservation of mass, momentum and energy, specific energy, friction losses, minor losses, uniform flow, normal depth.
  • Critical flow and wave celerity, hydraulic jumps and weirs, discharge measurements.
  • Water surface profile calculations, introduction to HEC-RAS, calibration/validation.
  • Material and sediment transport, erosion and self-cleansing, design of channels and drainage pipes.
  • Culvert hydraulics and culvert design, introduction to HY-8.
• Unsteady one-dimensional flow:
  • Introduction to St. Venant's equations and principles for numerical solution
  • Introduction to the pipe flow component of SWMM, calibration/validation.
• Unsteady two-dimensional flow:
  • Introduction to the shallow water equations and principles for numerical solution.
  • Introduction to/demonstration of 2D simulations in HEC-RAS.

Knowledge:

• The student can understand and describe the basic physical principles and equations for steady one-dimensional flow in open channels
• The student can understand and describe the equations for uniform flow and what role uniform flow plays as an equilibrium state in open channel flow
• The student can understand and describe the phenomenon of critical flow, and what practical and computational consequences it has for open channel flow
• The student can understand and describe the principles for computing water surface profiles and how these are implemented in HEC-RAS
• The student can understand and describe the basic principles and equations for material and sediment transport, sedimentation and erosion in channels and drainage pipes
• The student can understand and describe different flow regimes in culverts, and principles for design and capacity assessment of culverts
• The student can understand and describe St. Venant's equations, including common simplifications of the equations
• The student is familiar with principles for solving St. Venant’s equations numerically, including how the solution is implemented in SWMM
• The student is familiar with the shallow water equations and how their numerical solution is implemented in HEC-RAS
• The student can understand and describe principles for calibration and validation of models for open channel flow

Skills:

• The student can apply the knowledge in the list above to solve simple open channel flow problems, including basic design of channels, drainage pipes and hydraulic structures, manually or with general numerical software
• The student can carry out basic hydraulic analyzes and design in the software packages HEC-RAS, HY-8 and SWMM
• The student can make critical assessments of input and output data from hydraulic software and interpret typical numerical diagnostic messages that such software gives the user

General competence:

• The student has gained experience with using engineering software
• The student has gained experience in understanding the connection between a mathematical model in the form of a set of equations, and the numerical implementation that tailor-made software packages offers
• The student has gained experience with calibrating models that contain uncertain parameters
• The student has gained experience in setting up and implementing numerical solutions of simple (differential) equations in general numerical software