Abstract
We consider two unsteady free convection flows of a Bingham fluid when it saturates a porous medium contained within a vertical circular cylinder. The cylinder is initially at a uniform temperature, and such flows are then induced by suddenly applying either a new constant temperature or a nonzero heat flux to the exterior surface. As time progresses, heat conducts inwards and this may or may not overcome the yield threshold for flow. For the constant temperature case, flow begins immediately should the parameter, Rb, which is a nondimensional yield parameter, be sufficiently large. The ultimate fate, though, is full immobility as the cylinder eventually tends towards a new constant temperature. For the constant heat flux case, the fluid remains immobile but will begin to flow eventually should Rb be sufficiently large. The two cases have different critical values for Rb.
Original language | English |
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Pages (from-to) | 711-728 |
Number of pages | 18 |
Journal | Transport in Porous Media |
Volume | 127 |
Issue number | 3 |
Early online date | 19 Dec 2018 |
DOIs | |
Publication status | Published - 1 Apr 2019 |
Keywords
- Porous media; Boundary layer; Unsteady flow; Convection; Bingham fluid; Yield stress; Vertical cylinder
- Porous media
- Vertical cylinder
- Bingham fluid
- Unsteady flow
- Yield stress
- Convection
- Boundary layer
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis