Hydraulic Characteristics
Flow regime in foam materials has its own peculiarities which have to be considered. Resistance to flow through the material is substantially nonlinear. Cumulative hydraulic resistance corresponds to Darcy flow completely and can be described by dependence of the following type:
where 
— pressure drop at length h, V — speed of flow, α and β — accordingly viscous and accelerative factors of resistance determinated by structure parameters of a foam material. You can see estimated values of foam materials’ resistance at different porosity factors in the schedule below.
Another feature of flow through foam materials is high flow turbulization. Unique open cellular net structure provides the best conditions of heat — and mass — transfer and more effective utilization of material surfaces. Dependence of «Re» criterion on porosity, at which gas flow turbulization occurs for honeycomb and cellular structure materials is presented in the schedule below.
Foam material structure, at liquid or gas flow, even at small Reynolds numbers turbulizates and mixes the flow intensively near the material surface. This feature can be used in various processes of heat — and mass — transfer: aerosol and gas division, fast
