CE 40450 – Hydraulics

Andrew Kennedy168 Fitzpatrick

Andrew.kennedy@nd.edu

Hydraulics• What does hydraulics mean for engineers

and what are typical hydraulic engineering problems?

• How do these interact with other engineering disciplines?

• What will we be covering in this course?• What will we not be covering in this

course?

Notre Dame as an Example

August 16, 2016

• 1 in XX hundred year storm, one week before classes started

• Flooded Fitzpatrick, causing large damage to first floors and basement levels

• Two senior design teams worked on solutions last year

Sample Hydraulics and Hydrology Topics• What will be the runoff from Notre Dame into St Mary’s Lake after a one in

ten year storm? How much flooding will there be?• How do we design a stormwater collection system for Notre Dame to ensure

that Fitzpatrick Hall does not flood again?• What will be the maximum water levels in a river or stream after a storm or

during typical flows?

• How do we design a spillway for the maximum expected flow at the South Bend Dam? What will be the maximum water levels?

• What hydroelectric power can we generate given typical flows and what will be the best turbine setup?

• How do we design a distribution system to transport drinking water or wastewater through a network?

• What will be the pollutant runoff and fate from a property, subdivision or from a farmer’s field?

• How do we prevent erosion or sedimentation, or remedy these effects?• What will be the maximum water levels and damage during a hurricane?• What can/should we do with a 140 year old dam that is decaying?

Nutshell Description

• Engineering Hydraulics ensures that water:– Goes where it should go– Does not go where it should not go– Is used beneficially (water supply, power,

recreation, industry)– Does not have adverse effects (i.e. pollution,

erosion, structural damage)

• Warren Buffett, businessman:– First come the innovators, who see

opportunities that others don’t. – Then come the imitators, who copy what the

innovators have done. – And then come the idiots, whose avarice

undoes the very innovations they are trying to use to get rich.

Before we Start

This course

Tips on How to Approach This Course

• Most of the first two thirds of the course rely on principles and techniques– If you learn the principles, then you just need

to apply the techniques to solve problems– Principles also help you with new situations

• The last third of the course is more application of observations, and approximate engineering solutions

1. Pumps, Turbines and Pipe networks– Moment of Momentum Revisited– Types of pumps and turbines and uses– Pump-pipe systems, networks

2. Open Channel Flow– Specific Energy and Rapid Transitions– Hydraulic Jumps– Slowly varying flow– Open channel control structures

3. Introduction to Surface Water Hydrology– Hydrologic Cycle– Rainfall, Runoff and Design Events

4. Hydraulic Structures – Dams, weirs, spillways– Culverts– Safety and Effects of Hydraulic Structures

Course Topics

Important Things Not Covered in This Course

• Detailed Drainage Design– Sewers, culverts, subdivision, city drainage, etc.

• Pollutant Transport and Mixing• Coastal Engineering

– Storm surge, shore protection, erosion, wave damage• Sediment Transport, Scour, and Morphological Changes• River Engineering, Ports, Harbors, Navigation Engineering• Hydrodynamic Loading on Structures• Much Hydraulic Software

– HEC-RAS etc.

Pumps and Turbines• What type of pumps and turbines are

available for different applications?• Pump and turbine theory• Choose a suitable pump or turbine for a

given situation and design a distribution pipe network

Typical pump rating curve

Water Distribution Pipe Network

Water, gas, chemicals, etc.

Open Channel Flow• When is open channel flow important?• What are the regimes of open channel flow and

why are they different?• How do water levels change with different flows,

and moving up/downstream?• What is a hydraulic jump and how does it affect

flow?• What is the role of bottom friction?• How can we predict simple flows?

Open Channel Flow

Subcritical flow

Supercritical flow –hydraulic jump

Link1 Link2

Hydrology• A basic question of engineering hydrology: what flows

should we expect?• What is the once in ten year rainfall over a 24 hour period?

– What runoff will this produce?– What will be the time history?– How long will it take for flow to develop?– How will this vary from location to location?– How will this vary with soil type/antecedent moisture?

• Often hydrology provides design flows for hydraulic engineering

• Here, mainly surface water hydrology– Some other types: groundwater hydrology, contaminant hydrology– We follow what is covered on the FE exam

Hydrologic Cycle

Hydraulic Structures

• What are examples of hydraulic structures and what are they used for?– Dams– Spillways– Weirs– Tunnels and culverts– Stilling basins

• What are the broader implications of hydraulic structures?

Dams – Forces, Power Generation, Flood Control

Mount Morris Flood Control Dam, Letchworth State Park, NY

Partially full Empty

Hurricane Irene (First class 2011)

First Day of Class 2012

First Day of Class, 2013

First Day of Class, 2014

First Day of Class, 2015

In the Indian Ocean near Madagascar, nowhere near here

First Day of Class, 2016

Was Category 4, but seems to be winding down without major landfalls

First Day of Class, 2017

No storms, very quiet …