a

The long axis of a prolate ellipsoid, m, b is the short radius, m.

a

The radius of the fiber in cylinder or cell models, m

A

1. Filter area, m ²

2. Tensile test - the area under the load-elongation curve, J.

3. ASHRAE arrestance, ASHRAE 52-1, %

a/b

The length/diameter ratio of a prolate ellipsoid, dimensionless

b

Diameter of a prolate ellipsoid at its center or thickest part, m

b

The radius of the outer cylinder in cylinder or cell models, m

B

Langmuir correction factor for determining the resistance of fibers

transverse to the flow from the resistance of fibers parallel to the flow,

dimensionless

B

Bechold correction factor or capillarity constant for tortuosity in

the bubble point test. It has the value of 0.715 in ASTM F316,

dimensionless BL Breaking length, m

c

The mass concentration of fiber per unit volume of medium, kg/m ³

cp

Particle concentration of an air stream approaching a filter element,

particles/m ³

C

1. A constant in the solution to the biharmonic equation

2. Brunauer, Emmet, Teller (BET) Equation - a constant relating the adsorption energy of a gas to a solid substrate as compared to the liquefaction energy of the gas, dimensionless

C _d

The drag coefficient, dimensionless

^Cd _?

Drag coefficient of a cylinder moving in a tank - White's equation, dimensionless

C' _D

Payet correction to single fiber efficiency models, dimensionless

C _D and

Correction terms applied by Rubow to...