Water Supply Engineering Flashcards
Branch of continuous mechanics which deals with the study of all fluids under static and dynamic situations
Fluid Mechanics
Fluids at rest
Fluids Statics
Deals with velocities and streamlines w/o considering forces or energy
Kinematics
Deals with the relations between velocities and accelerations and forces exerted by or upon fluids in motion
Fluid Kinetics/Dynamics
Deals with the application of fluid mechanics to engineering devices
Hydraulics
Deals with the flow of fluids that undergo significant density changes
Gas Dynamics
Deals with the flow of gases over bodies such as air vehicles. Helps also in designing them
Aerodynamics
It is the study of materials showing dual behaviors; under certain limits; it behaves like solids and under others behaves like fluid
Rheology
Convenient to assume fluids are continuously distributed throughout the region of interest
Continuum
It will deform at different rates. Directly proportional to stress and strain
Newtonian Fluid
Fluid in which shear stress is not directly proportional to deformation rate
Non-Newtonian Fluid
Shear thinning fluids, becomes less resistant to motion with increased strain rate
Pseudoplastics
Shear thickening fluids becomes more resistant to motion as the strain rate increases
Dilatants
It requires a minimum shear stress to cause motion
Bingham Fluids
Regions where frictional effects are significant. They are usually close to solid surfaces
Viscous Region
Regions where frictional forces are small compared to inertial or pressure force
Inviscid Region
Undergoes significant changes in density as they flow
Compressible Fluids
Does not undergo significant changes in density as they flow
Incompressible Fluids
The measure by which a physical variable is expressed quantitatively
Dimensions
Particular way of attaching a number to quantities
Unit
The amount of matter in a particle or object.
Mass
The force that gravitation exerts on a body
Weight
Mass per unit of volume
Density
The volume occupied by a unit of mass of fluid. Reciprocal of density
Specific Volume
Weight per unit volume
Unit/Specific Weight
A unitless ratio of a fluid’s density to some standard reference density, like water
Specific Gravity
Property of fluid that can be thought as the internal stickiness of a fluid; that is due to its resistance to shearing stress
Absolute/Dynamic Viscosity
The ratio of the dynamic viscosity of the fluid to its density. It is a quantity in which no force is involved
Kinematic Viscosity
To characterize the fluid compressibility of fluids. It is the reciprocal of coefficient of compressibility. Unit is pascal.
Bulk Modulus of Elasticity
It is the fractional change in the volume of a fluid per unit change in pressure in a constant temperature pressure
Compressibility
Force within the surface layer of a liquid that causes the layer to behave as an elastic sheet
Surface Tension
The ability of a narrow tube to draw a liquid upward against the force of gravity
Capillarity
A fluid has capillarity if
Cohesive Force, Adhesive Force, Surface Tension
A pressure wave disturbance in fluids. Speed of sound in a fluid
Celerity
Pressure wave travelling with the speed of sound caused by slight change of pressure to a compressible flow
Mach Angle/Number
Dimensionless value useful for analyzing fluid flow dynamics problems where compressibility is a significant factor
Cauchy Number
Force exerted by a fluid per unit area. It is transmitted with equal intensity in all direction and acts normal to any plane. In the same horizontal plane, the pressure intensifies in a liquid are equal.
Fluid Pressure
The pressure intensity at the base of a column of homogenous fluid of a given height in m.
Pressure Head
It is the pressure at the surface of the earth due to the head of air above the surface.
Atmospheric Pressure
Pressure measured above or below atmospheric pressure
Gauge Pressure
Negative gauge pressure. In outer space the pressure is essentially zero.
Vacuum Pressure
Measured above absolute zero or vacuum
Absolute Pressure
States that the pressure intensity at a point in a fluid at rest is the same in all directions
Pascal’s Principle
Assumed to have no Viscosity
Ideal Fluids
Experience friction during flow
Real Fluids
Incompressible
Ideal Fluids
Turbulence in Flow
Real Fluids
Non uniform velocity distribution when flowing
Real Fluids
Exhibit Infinite Vicosities
Real Fluids
No friction between moving layers of fluid
Ideal Fluid
Types of Non-Newtonian Fluid
Pseudoplastic Fluids, Delatant Fluids, and Bingham Fluids
It is the intermolecular bonding of a substance where its mutual attractiveness forces them to maintain a certain shape of liquid
Cohesive Force
Forces of attraction between unlike molecules
Adhesive Force
Formation of impenetrable surface on the body of water due to cohesive forces
Surface Tension
To guard against water hammer
Surge tanks
As per IS:1172-1963, water required per head per day for average domestic purposes, is _
135 liters
In slow sland filters, the turbidity of raw water can be removed only up to_
60mg/litre
Acidity in water is caused due to _
mineral acids, Free CO2, iron sulphate and aluminum sulphate
The transitional middle portion of a logistic curve follows a _
constant rate
Fire hydrants are fitted in water mains at _
100m to 150m apart at fire
The minimum water pressure
1 to 1.5 kg/cm2
The water pressure 1 to 1.5 kg/cm2 is made available for
4-5hrs for constant use
has the least specific retention
The coarse gravel
Most commonly used for lifting water supply mains
Axialflow Pump
Economic height of a dam is the height corresponding to
the cost of the dam per unit of storage is minimum
Distribution mains of any water supply, is normally designed for it average daily requirement of
225%
In pressure supply mains water hammer pressure is reduced by providing
pressure relief valves
Detention period for plain sedimentation tanks ranges between _
4 to 8 hrs
Detention period for sedimentation tanks, using coagulants usually ranges between _
2 to 4 hrs
The horizontally flow velocity in sedimentation tanks, is generally limited to
0.3 m/min
By boiling water, hardness can be removed if its due to
calcium bicarbonate
The least thickness of class B cast iron (spun) pipe is
8.6mm
Average annual rainfall at any station is the average of annual rainfall over a period of
35 years
Time taken for the storm water to travel from the most remote point to the drain
Time of concentration
Any stream flowing steadily w/out friction, the total energy contained in a given mass is the same at any point within its path of flow
Daniel Bernoulli’s energy Theorem
Rate at work is done
Power
It is used to increase the head or to raise or deliver water from a lower to a higher elevation
Pump
Mechanical work which produces electricity
Turbine
It is the graphical representation of the potential head. The line to which liquid rises in successive piezometer
Hydraulic Grade Line
Always above the hydraulic grade line by an amount equal to the velocity head
Energy grade line
States that the increase in the kinetic energy per unit weight is equal to the decrease in the potential energy per unit weight
Venturi meter
the American engineer that invented the venturi meter
Clemens Herschel
Tube with circular cross section bent in l-shape with both ends open is used for measuring velocity of liquid in an open flow
Pitot tube
it is a converging tube installed at the end of pipe or hose for the purpose of increasing the velocity of the issuing jet
Nozzle
study of movement of water beneath the earth’s surface
Geohydrology
Water beneath the surface can essentially be divided into 3 zones
1) the soil water zone or vadose zone 2) an intermediate zone and 3) the groundwater, or saturated zone
subsurface zone in which all rock openings are filled with water
Saturated or Phreatic Zone
a subsurface zone in which rock openings are generally unsaturated and filled partly with air and water; above the saturated zone
Vadose zone or Zone of Aeration
the upper surface of the zone of saturation.
Water table
a local zone of saturation may exist at some level above the main water table
Perched water table
Factors affecting the flow of groundwater
porosity of a soil, Soil permeability and Slope of the water table
A formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs
Aquifer
Confining bed that retards but does not prevent the flow of water to or from an adjacent aquifer
Aquitard
- A hydrogeologic unit which, although porous and capable of storing water, does not transmit it at rates sufficient to furnish of storing water, does not transmit at rates sufficient to furnish an appreciable supply for a well of spring
Aquiclude
- A hydrogeologic unit which has no interconnected openings and hence cannot store or transmit water
Aquifuge
Aquifer below the land surface that is saturated with water. Layers of impermeable material are both above and below the aquifer, causing it to be under pressure so that when the aquifer is penetrated by a well, the water will rise above the top of the aquifer
Confined Aquifer
An aquifer whose upper water surface is at atmospheric pressure and thus is able to rise and fall
Unconfined Aquifer
- The vertical distance the water elevation is lowered or the reduction of the pressure head to the removal of the water
Drawdown
A depression of the potentiometric surface in the shape of an inverted cone that develops around a well which is being pumped
Cone of depression
A deep hole, generally cylindrical, that is dug or drilled into the ground to penetrate an aquifer within the saturated zone.
Well
Constructed by either of a cable tool or rotary-drilling machines, drilled wells that penetrate unconsolidated material require installation of casing and a screen to prevent inflow of sediment and collapse
Drilled wells
Driving a small-diameter pipe into shallowly water-bearing sand or gravel. Usually screened well point is attached to the bottom of the casing before driving
Drive wells
Excavated by hand shovel to below the water table until incoming water exceeded the digger’s bailing rate.
Dug wells
A discrete place where the groundwater flows naturally from a rock or the soil onto the land surface or into a body of surface water
Spring
Taps heat under the earth’s crust to boil water. Used to drive electric turbines to produce electricity
Geothermal energy
Created when excess water from rain, snowmelt, or near-surface groundwater accumulates on the ground surface and begins to run downhill
Streams
the addition of new water to the saturated zone
Recharge
a stream that receives water from the zone of saturation
Gaining stream (Effluent Stream)
a stream that loses water to the zone of saturation
Losing stream (Influent Stream)
The part of the stream discharge that is not attributable to direct runoff from precipitation or melting snow, it is usually sustained by groundwater discharge
Base flow
icicle-like pendants of dripstone hanging from cave ceilings
Stalactites
cone-shaped masses of drip stone formed on cave floors
Stalagmites
closed depressions found on land surfaces underlain by limestone; either formed by the collapse of a cave rood or by solution as descending water enlarges a crack in limestone
Sinkholes
a natural pit or sinkhole, resulting from the collapse of limestone bedrock tat expose groundwater underneath
Cenote
An area with many sinkholes and with cave systems beneath the land surface
Karst topography
Develops when porous buried wood is either filled in or replaced by inorganic silica carried in by groundwater
Petrified wood
Hard, round mass that develops when a considerable amount of cementing material precipitates locally in a rock
Concretion
Partly hollow, globe-shaped bodies found in some lime stones and locally in other rocks
Geodes
Branch of applied sciences which deals with the measurement and description of the physical features of bodies of waters as well as with the prediction purpose of safety of navigation and in support of all marine activities.
Hydrography
body of fresh water completely surrounded on all sides by land
Lake
natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river
River
body of standing water, either natural or artificial that is usually smaller than a lake
Pond
part of the sea or river reaches into the land
Bay
a large area of ocean that is partly surrounded by land
Gulf
study of inland waters. It is often regarded as a division of ecology or environmental science
Limnology
The uppermost, warmest (and least dense) layer of a stratified lake
Epilimnion
middle zone, where the rate of change in temperature with depth is greatest
Metalimnion
deepest, coldest, most dense zone
Hypolimnion
The area drained by a river and its tributaries
Drainage basin
the beginning of a river
Source
the end of a river
Mouth
A small river that flows into a larger river
Tributary
where 2 rivers meet
Confluence
the border between 2 drainage basins
Watershed
the tidal section of a river near the mouth
Estuary
the physical confines of the river encompassing two banks and a bed
Channel
the sides of a river channel
Bank
the bottom of a river channel
Bed
