For a radial flow of a fluid through a porous medium, how do I calculate the radial flow area. The porous medium has an Internal Diameter (ID) and Outer Diameter (OD) and thickness (t). The flow takes place in in-plane flow configuration from ID and tends to OD. In order to calculate the superficial velocity of the fluid, the area needs to be determined. How to calculate the area when the flow is in radial direction. The formula {2*PI*t*(radius)} can be used to calculate the flow area and the superficial velocity? If so, which radius to consider since the flow is radial?
https://www.sciencedirect.com/search?qs=superficial%20velocity%20calculation&show=25&sortBy=relevance
Dear Nagadatta
Mind you, the outward radial fluid motion is accelerated! I’m assuming the flow rate is constant. Actually, the acceleration is negative and we can call it a decelerated fluid flow: the superficial velocity (q) decreases along the radius since the transversal flow area increases in the same direction. This type of acceleration is called convective. Take the fluid Linear Momentum Conservation Equation for a two-phase solid-fluid system. The convective acceleration corresponds to the term ρ(gradq/ε)q, where ρ is the fluid density and ε is the bed porosity, usually placed on the left hand side of the equation. May be the magnitude of this term is small compared to the force/unit solid-fluid volume terms on the right hand side. This must be checked case by case. Regarding your question, at most, what you can calculate are “reference velocities” at particular values of r (for instance, r = Di/2 or r = Do/2 or r = (Do - Di) / 4).
Note:
The superficial velocity (q) is, by definition, the velocity the fluid would have, in absence of the porous medium. In other words, it is the velocity the fluid actually has just before and just after the porous medium, that is, on the entrance and exit surfaces.
- Badges
- Science topic
- Similar topics
- Comment