Engineering calculators / Porous media
Multilayer Filter Resistance Calculator
Add the Darcy resistance of one to six planar layers in series, using independently established directional permeability values.
Examples are not product data. Unit changes convert existing values.
Formula and assumptions
Rtotal = Σ(Li / ki); Δp = μ × (Q / A) × Rtotal; keq = ΣLi / Rtotal
For steady, fully saturated, single-phase Newtonian liquid flow with constant viscosity in the linear Darcy regime. Use the gross exposed media area, not net opening area. Excludes inertial losses, compressible gases, gravity head, clogging, bypass, support/interface losses and housing losses. No material presets, rated capacity, service life or filtration efficiency are inferred. Example values are arithmetic examples, not product specifications.
All active layers share the same exposed gross area and the same steady liquid flow. Pressure losses add along the flow direction. Bonding or sintering can alter pore structure: a stack calculated from unbonded layers does not automatically describe the bonded product. This planar model is not a radial cylindrical-wall calculation or a parallel-flow model.
Frequently asked questions
What area should all layers share?
The common exposed gross area perpendicular to flow. This model does not support changing cross-sections or bypass.
Can I enter mesh opening percentage as permeability?
No. Enter independently measured or validated directional permeability in units of area.
Does this model include protective screens?
Only where a Darcy permeability is independently established and its linear regime is valid. Otherwise assess its loss separately.
Does equivalent permeability certify a sintered laminate?
No. Bonding and interfaces can change the actual resistance; validate the finished laminate.
Model reference: COMSOL Darcy’s law equation formulation. Series equations follow from adding each layer’s Darcy pressure drop under the common-area assumptions above.
