Abstract
In multiphase systems, boundary layers occur at fluid-fluid or fluid-solid interfaces. In a direct numerical simulation, the grid requirements are often dictated by the thickness of these boundary layers. Systems that are characterized by high Prandtl (or Schmidt number) exhibit temperature (or mass) boundary layers that are much thinner than the momentum boundary layers. In this paper, a hybrid computational approach is presented that uses a fixed Cartesian grid for the Navier-Stokes and continuity equations and an adaptive mesh for scalar transport, thus reducing the memory and CPU requirements tremendously while resolving all boundary layers. We describe the key aspects that need to be addressed in this hybrid approach, related to discretization, grid mapping, velocity interpolation along with detailed verification tests. Finally, the robustness and accuracy of our hybrid methodology is demonstrated for forced-convection heat transfer over stationary spherical particles at high Prandtl numbers.
| Original language | English |
|---|---|
| Article number | 100047 |
| Number of pages | 18 |
| Journal | Chemical Engineering Science: X |
| Volume | 4 |
| DOIs | |
| Publication status | Published - 1 Nov 2019 |
Funding
This work is part of the Industrial Partnership Programme i36 Dense Bubbly Flows that is carried out under an agreement between Akzo Nobel Chemicals International B.V., DSM Innovation Center B.V., Sabic Global Technologies B.V., Shell Global Solutions B.V., Tata Steel Nederland Technology B.V. and the Netherlands Organisation for Scientific Research (NWO). This work was carried out on the Dutch national e-infrastructure with the support of SURF Cooperative.
Keywords
- Adaptive mesh refinement
- Boundary layers
- High Prandtl number
- High Schmidt number