Recommendations
Circular weirRiver Self-Purification: Streeter-Phelps MethodDynamic viscosity of atmospheric airBrokaw's formulaWilke's multicomponent equationCentrifugal Decanter (Pieralisi)
Fuller's formula
Default

Input data

Temperature

Pressure

Molar mass of component A

Volume associated to the component A's diffusion (cm³/mol)

Molar mass of component B

Volume associated to the component B's diffusion (cm³/mol)

Output data

Diffusivity

Description

Calculate the diffusivity coefficient, which is considered a good estimate for non-polar gases.


The Fuller equation is recommended when it is not possible to obtain the Lennard-Jones parameters.


Given the temperature, pressure, molar mass, and associated volume of the components, the diffusivity coefficient, in cm²/s, is calculated using the Fuller equation:


DAB=1⋅10−3⋅T1.75P⋅(∑vA13+∑vB13)2⋅(1MA+1MB)12 D_{AB} = 1 \cdot 10^{-3} \cdot \frac{T^{1.75}}{P \cdot \left( \sum v_A^{\frac{1}{3}} + \sum v_B^{\frac{1}{3}} \right)^2} \cdot \left( \frac{1}{M_A} + \frac{1}{M_B} \right)^{\frac{1}{2}}

References

  • WELTY, James; WICKS, Charles E.; WILSON, Robert E.; RORRER, Gregory L. Fundamentals of Momentum, Heat and Mass Transfer. 5th Ed. John Wiley & Sons, 2008.