Momentum Transfer Flashcards
The viscosity of a gas
a. dec with inc in temp
b. inc with the inc in temp
c. is independent of temp
d. is independent of pressure for very high pressure identities
b. inc with the inc in temp
- bc pag ininit yung gas, magcocollide mga molecules, resulting to friction kaya bumabagal ang flow
Shear stress is __________ proportional to Force and viscosity
a. directly
b. inversely
a. directly
The dimensionless number that characterizes the flows of fluid in a conduit
Reynolds number
Re < 2100
Laminar
Re > 400
Turbulent
Smooth stream line for fluid flow
Laminar flow
Chaotic movement of fluid flow
Turbulent flow
Formed vortex in turbulent flow
eddies
ratio of inertial force to gravity force
Froude number (can be found in table 6-9)
Which valve is used accurately to regulate the flow of liquids and gases at low flow rates
needle valve
Mach number < 1, flow is
Subsonic
Mach number = 1, flow is
Sonic
Mach number > 1, flow is
Supersonic
Why is there no vapor in the pump
cavitation
Which of the following is not true
a. A pump will operate safely it its NPSH is greater than zero
b. Fans and blowers are used tk transport gases
c. Pumps and blowers increase the mechanical energy of the fluid
d. The power loss due to friction in a venturi meter is greater than in an orifice meter
d. bc of vena contrata (?)
How many schedule number for pipe
10
An important devuce for measuring pressure differences
Manometer
Type of manometer that is often used for measurement of small pressure differentials accurately
Inclined Manometer
Type of manometer where the the end of the U tube is connected to two large chambers.
Differential Manometer/Multiplying Gauge
standard atmosphere at sea level
1 atm
device used to measure air pressure in a certain atmosphere
baromter
He wrote “panta rhei” translated as “everything flows”
Heraclitus
resistance of a fluid to flow
viscosity
Liquid viscosity decrease when temp is raised
gas viscosity increases with temperature
Toothpaste, jellies, paints are examples of
Bingham fluids
Pseudoplastic fluids
Dilatany fluids
Bingham
blood is an example of
Bingham fluids
Pseudoplastic fluids
Dilatany fluids
Pseudoplastic
Polymer solution is an example of
Bingham fluids
Pseudoplastic fluids
Dilatany fluids
Pseudoplastic
Space where fluid and pipe surface separates
boundary layer
a motor that converts mechanical energy to electrical energy
Dynamo
Which statement is not true
a. Potential flow is a flow of compressible fluids with no shear
b. rotameters are variable headed meters
c. There are 8 schedule numbers for standard pipes
d. Roughness has no appreciable effect on the friction factor when flow is laminar
c.
