Dimensionless Anaylsis Flashcards
What are dimensions (give examples)
these are qualitative description (L, M, T)
What are (physical) quantities?
quantitative description (numerical value and measuring unit
What kind of quantities do we know?
primary and scondary quantities
When is a process consider as completely similar?
similar geometrical space and if all the dimensionless numbers have the same numerical value
what types of similarities do we have?
geometric, kinematic and dynamic
what is a geometric similarity?
similarity of shape, ratio of all corresponding linear dimensions in model and prototype are equal
kinematic similarity
similarity of motion,
ratio of velocities
dynamic similarity
similarity of forces, ratio of forces
which type of model do we have?
true and distored models
difference between the true and distored models?
true models have the same scale ratios in very direction, while distorted model have different scales in different directions used
example of primary quantities
lengt, mass, time, thermodynamic temperature
amount of substance
electric current
luminous intensity
give the base dimenion and the SI base unit of lengt, mass, time,
length: BD =L, SI =m
mass: BD=M, SI=kg
time: BD=T, SI=s
give the base dimenion and the SI base unit of thermodynamic temperature
amount of substance
thermodynamic temperature: BD: SI =K
amount of substance: BD=N, SI=mol
give the base dimenion and the SI base unit of electric current
luminous intensity
electric current: BD: I SI =A
luminous intensity: BD=J, SI=cd
secondary quantities, exsamples
know the unit and dimensions
force, pressure, energy and power