Modular In BQ, HF, NC, 2phase Flashcards
A special case of the general energy equation that is probably the most widely used tool for solving
Bernoulli’s Equation
It provides an easy way to relate the elevation head, velocity head, pressure head
Bernoulli’s equation
It is possible to modify bernoulli’s equation in a manner that accounts for ____ and _____
Headloss and Pumpwork/pumphead
Bernoulli’s Equation results from the application of the general energy equatin and first law of thermodynamics to a steady flow system in which:
No work is done on or by the fluid
No heat transfered from or to the fluid
No change occurs in the internal energy ( ex change in temperature change) of the fluid
Used by engineers in reference to pressure. It is reference to the height, typically in feet, of a column of water that a given pressure will support.
Head
Thus, bernoulli’s equation states that the total head of the fluid is ___
Constant
Restrictions on the simplified Bernoulli’s Equation
No fluid friction ( head losses )
No work on or by the fluid ( pump work or pump head)
___ due to friction (Hf) represents the energy used in overcoming friction caused by the walls of the pipe
Head Loss
Is a flow measuring device that consists of a gradual construction followed by a gradual expansion
Venturi
T or F. The flow velocity at the throat of the venturi and the volumetric flow rate are directly proportional to the square root of the differential pressure.
True
- Correction Factor to solve the actual velocity and actual volumetric flow rate
- Account for friction losses and equals 0.98 for most venturi’s
Venturi factor
Fluid situations must applied Bernoulli’s Equaiton:
- Incompresible, steady flow with no internal friction
- Incompresible flow with internal friction
Measure of the reduction in the total head ( sum of elevation head, velocity head and pressure head ) of the fluid as it moves through a fluid system
Head Loss
T or F. Head loss is unavoidable in ideal fluids
F, Beacuse head loss is unavoidable in real fluids
Caused whenever the flow is directed or affected in any way by such components as piping entrances and exits, pumps, valves, flow reducers and fittings.
Turbulence
Part of the total head loss that occurs as the fluid flows through straight pipes
Friction Loss
The friction factor has been determined to depend on the _________ for the flow and the degree of roughness of the pipe’s inner surface
Friciton Factor
The quantity used to measure the roughness of the pipe
Relative Roughness
The average height of irregulararities (€) divided by the pipe diameter
Relative roughness = €/D
The frictional head loss can be calculated using mathematical relationship that is known as _____. The equation using teo distinct forms.
Darcy’s Equation
The first form of Darcy’s Equation determins the losses in the system _______.
Associated with the lenght of the pipe
The losses thar occur in pipelines due to bends, elbows, joints, valves, etc are sometimes called ____
Minor Losses
Darcy’s Equation ( 2nd Form )
Minor Losses
True or False. For all minor losses in turbulent flow, the head loss varies as the square of the velocity
True
Minor Losses may be expressed in terms of the ________ (Leq) of the pipe would have the same head loss fornthe same discharge flow rate
Equivalent Lenght
T or F. By adding the equivalent lenghts of all components to the actual lenght of pipe in a system we can obtain the Leq value for the entire piping system
T
