CBE Midterm 1

SI Units of Force

m l t^-2

SI units of energy

m l² t^-2

si units of power

m l² t^-3

si units of pressure

m l^-1 t^-2

si units of surface tension

m t^-2

heat capacity

m l² t^-2 degree^-1

What Reynold’s Number Measures

Compares inertial forces and viscous forces

Reynold’s number formula

density * velocity * length / bulk viscosity or velocity * length / kinematic viscosity

General balance equation

in - out + generation - consumption = accumulation

Mass fraction formula

mass solute / mass solution

mole fraction formula

mole solute / mole solution

solubility ratio

g solute/ 100 g solvent

mole fraction as mass fraction (x)

(x/M)/(x/M+(1-x)/Ms)

solubility ratio as mass fraction (x)

100*x/(1-x)

mass fraction as mole fraction (x)

Mx/(Mx+(1-x)Ms)

solubility ratio as mole fraction (x)

(100Mx)/((1-x)*Ms)

composition ratio as mass ratio (x)

x/(1-x)

mass ratio as composition ratio ( r )

r / 1+ r

composition ratio as mole fraction (x)

xA * MA/(1-xA)MB

mole fraction as composition ratio ( r)

r*MB/r*MB+MA

Bond number definition

Compares gravitational forces vs surface tension (drop vs. sheet)

Bond number formula

change in density x gravity x length ² / surface tension

Bond number formula with capillary length

(length / capillary length) ²

Capillary length formula

(surface tension / density x gravity) ^ 1/2

Capillary number formula

dynamic velocity x velocity / interfacial tension

capillary number definition

viscous forces vs surface tension (droplets vs stream)

Peclet Number definition

advection vs diffusion (tight stream vs loose stream)

Peclet number formula

viscosity x length / diffusion coefficient

Biot Number definition

internal heat resistance vs external heat transfer (conduction vs. convection)

Biot number formula

convective heat transfer x characteristic length / thermal conductivity

Units of convective heat transfer

W/(m² x K)

marangoni number formula

surface tension x length / diffusivity x viscocity