Model film transfer quickly using practical engineering inputs. Switch methods, visualize trends, and export results. Make diffusion calculations easier for studies, design, and reporting.
Use one of three methods: direct flux data, molar rate with area, or the Sherwood relation. Results appear above this form after submission.
The chart shows predicted flux versus concentration difference using the calculated mass transfer coefficient.
Use this when molar flux and the driving concentration difference are known. The result gives the individual mass transfer coefficient.
When only molar rate and interfacial area are known, convert them to flux first. Then evaluate k from the first relation.
Use this dimensionless correlation when Sherwood number, diffusivity, and characteristic length are available from theory or experiments.
| Case | Method | Key Inputs | Calculated k (m/s) | Comment |
|---|---|---|---|---|
| Absorption test A | Flux and ΔC | N = 0.012 mol/m²·s, ΔC = 2.5 mol/m³ | 0.004800 | Useful for direct lab measurements. |
| Membrane run B | Rate and area | ṅ = 1.8 mol/s, A = 0.65 m², ΔC = 220 mol/m³ | 0.012587 | Converts bulk throughput into flux first. |
| Channel flow C | Sherwood relation | Sh = 125, D = 1.9×10⁻⁵ m²/s, L = 0.05 m | 0.047500 | Best when correlations describe the flow field. |
It measures how quickly a species moves across a boundary layer for a given concentration driving force. Larger values indicate easier transfer between phases or between fluid regions.
Choose the flux method when experiments directly provide flux. Choose the rate method when you know total molar transfer and area. Choose the Sherwood method when transport correlations are available.
The coefficient is defined relative to the concentration driving force. If the concentration difference is very small, the same flux implies a much larger coefficient.
Yes. The calculator is suitable for gas-liquid, liquid-liquid, membrane, and many diffusion film problems, provided the selected inputs match the physical model behind your case.
Meters per second is the most common SI unit. This page also converts the result to centimeters per second, millimeters per second, and feet per second.
Sherwood number is a dimensionless transfer parameter. It links convective mass transfer to diffusion, similar to how Nusselt number links heat transfer to thermal conduction.
Resistance is simply 1/k. It helps compare barriers to transfer. Higher resistance means slower transport and usually stronger film limitations.
They are useful for screening, education, and preliminary sizing. Final design should also check correlations, property variation, interfacial behavior, and experimental validation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.