Dimension Analysis

Question 1

Ratio of activation energy to
thermal energy

Answer 1

arrhenius number

Question 2

Ratio of yield stress to viscous
stress

Answer 2

bingham number

Question 3

Ratio of the solid’s internal
thermal resistance to the fluid’s
thermal resistance

Answer 3

biot number

Question 4

Ratio of gravitational and surface
tension forces

Answer 4

bond number

Question 5

Ratio of heat generated by viscous
dissipation to the heat transferred
by conduction

Answer 5

brinkman number

Question 6

Reaction time scale versus
transport phenomena properties.
Definition depends on system. Eq
given is for continuous reactors.

Answer 6

Damkohler number

Question 7

Relates kinetic energy of flow with
enthalpy

Answer 7

eckert number

Question 8

Ratio of pressure force to inertia
force

Answer 8

euler number

Question 9

Ratio of rate by heat conduction to
rate of thermal energy storage.

Answer 9

fourier number

Question 10

Dimensionless pressure drop for
internal flow

Answer 10

friction factor

Question 11

Ratio of inertia force to the gravity
force

Answer 11

froude number

Question 12

Relates viscous flow and thermal
expansion

Answer 12

galileo number

Question 13

Determines the thermal or
concentration development at
entrance lengths of ducts

Answer 13

graetz number

Question 14

Ratio of buoyancy forces to
viscous forces

Answer 14

grashof number

Question 15

Ratio of sensible to latent heat
absorbed during evaporation or
condensatíon

Answer 15

jacob number

Question 16

Ratio of molecular mean free path
to a physical length. Given
cquation is for ideal gas.

Answer 16

knudsen number

Question 17

Ratio of thermal and mass
diffusivities

Answer 17

lewis number

Question 18

A proportionality constant that
relates the thermal conductivity, k
with electrical conductivity

Answer 18

lorentz number

Question 19

Ratio of the speed of fluid flowing
and that of sound measured at the
same conditions

Answer 19

mach number

Question 20

Dimensionless temperature
gradient at the surface

Answer 20

nusselt number

Question 21

Dimensionless independent heat
transfer parameter

Answer 21

peclet number

Question 22

Relates resistance forces to inertia
forces in agitators. Known also as
Newton Number.

Answer 22

power number

Question 23

Ratio of momentum and thermal
diffusivities

Answer 23

prandtl number

Question 24

Determines free heat convection
effects relative to the effect of fluid
motion

Answer 24

Rayleigh number

Question 25

Ratio of inertia and viscous forces

Answer 25

schmidt number

Question 26

Dimensionless concentration
gradient at the surface

Answer 26

sherwood number

Question 27

Modified Nusselt Number

Answer 27

stanton number

Question 28

Ratio of inertia to surface tension
forces

Answer 28

weber number