Ελληνικά

Hydraulics and Hydraulic Works

Course Description:

Basic principles and computational methods of applied hydraulics (pressurized pipes, free surface conduits). Design of main hydraulic works and associated systems (aqueducts, pumps and their discharge pipes, water supply works, tanks, water distribution networks, channels, sewage networks, urban drainage works, flood protection works).

Prerequisite Knowledge

Fluid Mechanics, Engineering Hydrology

Course Units

# Title Description Hours
1 Introduction Hydraulics and Hydraulic Works: definitions, historical evolution, importance. 5
2 Hydraulics of pressurized pipes Boundary shear stress. Reynolds number. Laminar and turbulent flow. Hydraulic radius. Energy grade line. Hydraulic grade (piezometric) line. Calculation of friction energy losses. Equivalent roughness. Roughness coefficients. Commercial pipes. 5
3 Special issues of pressured flow Converging and diverging flow. Local (minor) head losses. Hydrodynamic machinery. 3
4 Design principles for water transfer works General layout of aqueducts. Layout in horizontal plan and vertical profile. Siphons. Problems of negative pressure. Typical cross sections. 3
5 Pumping stations and discharge pipes Basic concepts (power and energy, hydraulic head, operation point, efficiency). Cavitation, water hammer. Technical and economical optimization of pumping systems. 3
6 Design principles of water supply works Design and operation specifications of water supply works. Abstraction works from surface and groundwater resources. General layout of water transfer works, pumping stations, tanks, water distribution networks. Pipeline and channel materials. 3
7 Design flows of water supply works Urban water uses. Demand and associated factors. Design population. Temporal distribution of water consumption. Typical peak coefficients per water use. Water losses. Emergency flows. 2
8 Tanks Tank types. Hydraulic design. Inflow-outflow curves. Estimation of regulation capacity and emergency volume. 3
9 Water distribution networks Typical diameters. Layout in horizontal plan. Pressure zones. Location of fire hydrants and specific devices (valves). Isolated zones. PRVs. Leakages. 3
10 Hydraulic analysis of water distribution networks Network mode schematization. Estimation of output flows. Formulation of scenarios for normal and emergency operation. Numerical solving techniques. Pipeline sizing and associated constraints. Software applications. 4
11 Basic principles of free surface flow Classification of free surface flow (steady – unsteady, uniform – non-uniform). Wave propagation velocity. Froude number. Specific energy. Specific power. Critical depth. 4
12 Uniform flow Manning’s formula. Calculations for prismatic channels. Composite cross-sections. Optimal cross-sections. Design principles for natural and constructed channels. 3
13 Critical depth and non-uniform flow Subcritical and supercritical flow. Flow surface profiles. Hydraulic jump. Typical problems. 6
14 Sewer hydraulics Flow conditions. Hydraulic calculations for steady uniform flow in circular conduits. Varying roughness coefficient. 4
15 Sewage works General layout of sewage works. Combined and separate networks. Wastewater treatment plants. 2
16 Estimation of sewage flows Design period, water consumption and sewer discharge, time-distribution of sewage flows, infiltration and inflows. 2
17 Design principles for sewer networks Specifications and constraints. Velocity limits. Minimum slopes. Transitions. Local (minor) losses. Problems of large and small velocities. 4
18 Wastewater quality and technological issues of sewer networks Composition of domestic sewage. Ventilation. Production of hydrogen sulfide and its quantification. Commercial pipes. Corrosion and anti-corrosion protection. Typical sewer shafts. 2
19 Urban floods and estimation of flood flows General design principles. Urban and rural catchments. Return periods. Catchment delineation in urban environment. Rational method. Estimation of characteristic design quantities (time of concentration, critical rainfall intensity, runoff coefficient). 3
20 Design principles for urban drainage networks Methodology of delineation and calculation of urban drainage networks in horizontal plan and vertical profile. Hydraulic controls. Construction and hydrological constraints. 3

Learning Objectives

By the completion of the course, the students will be able to:

  • understand basic concepts and apply typical computational techniques of pressurized and open channel hydraulics;
  • design typical water transfer works (pressurized pipes, pumping stations, channels);
  • design typical water supply works (aqueducts, tanks, water distribution networks) and handle models of hydraulic analysis of water networks (using the free software EPANET);
  • design sewer networks and drainage networks in urban environment;
  • employ elementary technical-economical optimization at a preliminary design phase;
  • recognizing essential elements for elaborating associated studies (technical report, general layout, pipe profiles);
  • Collaborate to solve composite design problems.

Teaching Methods

Teaching methods Continuous flow of theoretical concepts and applications
Teaching media Blackboard use and Powerpoint presentations
Computer and software use Use of spreadsheets and the free software EPANET (hydraulic analysis of water distribution networks)
Problems - Applications 10-12 problems are discussed and solved in class
Assignments (projects, reports) Technical studies for four types of urban hydraulic works, in groups of two or three students (optional assignments covering the respective subjects of the course): 1. Design, calculation and economic analysis of a composite aqueduct system 2. Schematization and solving of a water distribution network 3. Calculation and design of a sewage pipe profile 4. Hydrological and hydraulic study of a part of urban drainage network
Other Two-day visit at parts of the Athens water supply system (Mornos dam, Amphissa siphon, Giona hydroelectric work) or one-day visit to the wastewater treatment plant of Athens at Psyttaleia island.

Student Assessment

  • Final written exam: 70%
  • Mid-term exam: 30%
  • Assignments (projects, reports): +1 unit (bonus)

Textbooks - Bibliography

  1. Stamou, A., Applied hydraulics - Pressured and open channel flow, 3rd edition, Papasotiriou, Athens, 2016 (in Greek).
  2. Koutsoyiannis, D., and A. Efstratiadis, Lecture Notes on Urban Hydraulic Works - Water Supply, 83 pages, doi:10.13140/RG.2.1.3559.7044, National Technical University of Athens, February 2015 (in Greek).
  3. Koutsoyiannis, D., Design of Urban Sewer Networks, Edition 4, 180 pages, doi:10.13140/RG.2.1.2169.1125, National Technical University of Athens, Athens, 2011 (in Greek).