Hydraulics Flashcards
Velocity is constant at any point
Steady Flow
Flow is constant at any cross section
Uniform flow
Flow where energy is conserved
Continuous Flow
Stored energy based on position
Potential Head
Fluid energy due to its motion
Kinetic Head
Drop of head between two progressive sections in the flows
Head Loss
Head of a point based on its height above its set horizontal datum
Elevation head
Head on a point on its ambient pressure
Pressure head
Losses due to inherent properties of the channel or comduit
Major losses
Losses due to changes in direction brought about by curvature or fittings
Minor Losses
Irregularities of the fluid motion
Turbulence
RE<2000
Laminar Flow
Individual streamline does not intersect
Laminar flow
Transition from laminar to turbulent
Transitory
Individual streamline continuously instersect
Turbulent Flow
The rate or discharge of a flow
Continuity Equations
Q=AV
Continuity Equations
Graphical representation of the potential head
Hydraulic Grade line
Graphical representation of the specific energy
Energy grade line
Devices that add energy to the flow
Pumps
Devices that take energy to the flow
Turbines
Short tube that narrow on the end, directing the exit of fluids from the flow
Nozzles
The rate at which work is being done
Power
The output power of the devices
Rating
The percentage of the input transpired into useful work
Efficiency
Poutput/Pinput *100%
Efficiency
Amount of fluid passing through a section per unit of time
Discharge or flow rate
This occurs when the discharge Q passing a given cross section is constant with time. if the flow Q at the cross section varies with time the flow is unsteady
Steady flow
This usually occurs when an incompressible fluid flows through a stream with uniform cross section. In stream where the cross section and velocity changes the flow said to be non-uniform
Uniform flow
This occurs when at any time the discharge Q at every section of the stream is the same
Continuous flow
When the path of individual fluid particles do not cross or intersect. The reynold numbers is less than 2100
Laminar flow
When the path of individual particles are regular and continuously cross each other. it normally occurs when the reynold numbers exceed 2,100
Turbulent flow
Laminar flow in circular pipes can be maintained up to values of R as high as _______
50,000
This occurs when in an incompressible fluid the direction and magnitude of the velocity at all points are an identical
One dimensional flow
This occurs when the fluid particles move in planes or parallel planes and the streamline patterns are identical in each plane
Two dimensional flow
These are imaginary curves drawn through a fluid to indicate the direction of motion in various section of the flow of the fluid system
Streamlines
This represents elementary portions of a flowing fluid bounded by a group of streamlines which comfine the flow
Stream tubes
These are drawn to indicate flow patterns in case of two dimensional flow or even three dimensional flow
Flow nets
•Slopes downward in a direction of flow but it may rise or fall due to changes in velocity and pressure
•uniform 5 cross section hgl is parallel to egl
•for horizontal pipes with uniform diameter the drop in pressure heads between any two points is also equal to the head loss between these points
Hydraulic grade line
• always load downward in the direction of flow and it will only rise with the presence of a pump
•the drop of the egl between any two points is the head loss between those points
•for uniform piper section egl is parallel to HGL
•EGL IS ALWAYS ABOVE THE HGL BY AN AMOUNT EQUAL TO THE VELOCITY HEAD
Characteristic of energy grade line
The ratio of actual discharge to the device to the ideal or theoretical discharge which would appear without losses
Coefficient of discharge
The ratio of the actual mean velocity to the ideal or theoretical velocity which should occur without any losses
Coefficient of velocity
Ratio of the actual area of the contracting section of the stream or jed to the area of the opening through which the fluid flows
Coefficient of contraction
Opening with a close perimeter through which fluid flows
Orifice
Instrument used in measuring the discharge through pipes
Venturi meter
A converging tube installed at the end of the pipe or hose for the purpose of increasing the velocity of the issuing jet
Nozzle
A belt tube with both ends open and is used to measure the velocity of fluid flow or velocity of air flow as used in airplanes speedometer. Most common shapes are l-shaped and u shape
Pitot tube
It is a close conduit through which fluids or gases flows
Pipes
Conduits flowing partially full are callled _________
Open channels
The flow said to be_____ when the part of individual fluid particles do not cross or intersect. The reynolds number is less than 2,000
Laminar flow
The flow said to be ______ when the path of individual particles are irregular and continuously cross each other
Turbulent Flow
The velocity below which all turbulence are dumped out by the viscosity of the liquid
Critical velocity
A tube that has one with square corners entrance and has a length of about 2.5 times its eternal diameter
Standard short tube
Is an opening in a dam or other hydraulic structure to control the passage of water. It has the same hydraulic properties as the orifice
Gates
It is a tubes that has the form of a prism of a right circular cone with the larger and adjacent to the tank or reservoir
Converging tube
A tube that has form of a frustum of a right circular cone with a smaller and adjacent to the reservoir or tank
Diverging tubes
These are tube having their ends projecting inside a reservoir or tank
Re-entrant tube
The example of this tube is a culvert conveying water through embankments
Submerged tube
Overflow structures which are built across an open channel for the purpose of measuring or controlling the flow of liquids
Weir
The overflowing stream in weir
Nappe
The edge or top surface of a weir with which the flowing liquid comes in contract
Crest of weir
Weirs having sides sharp edge so that the nappe is contracted in width or having and contractions either one end or two ends
Contracted weir
Weirs having its length being equal to the width of the channel so that the nappe suffers no end contraction
Suppressed weir or full width weir
The downford curvature of the liquid surface before the weir
Drop down curve
The distance between the liquid surface and the crest of the weir measured before the drop down firm
Head