Abstract
The thermal convection of water and aqueous solution of sodium chloride (concentration 1.5% and 7%) is investigated experimentally and numerically in a cubic cavity, with two opposite vertical walls kept at preserved temperature. The analysis is caried out for the pure convection of water and its solute cold (wall temperature Tc= 0°C). The opposite hot wall temperature is fixed at Th =+5°C, +10°C and +15°C. The time history of the velocity fields are measured using liquid crystals seeding. It was observed that the thermal boundary conditions of non-isothermal side walls have a triggering effect on the flow configuration. Investigated thermosolutal convection demonstrated transition from a double-circulation flow pattern observed for the pure water (Th = +10°C and +15°C) to the single, double roll circulation at the upper part of the cavity with a wide stagnant layer at the bottom. The Finite Element model is used to simulate heat transfer and fluid flow in the water driven by heat conduction and buoyancy forces. The fixed grid algorithm is based on the semi-implicit operator splitting technique tied with the enthalpy-porosity approach. In the numerical investigations the adiabatic TBC have been tested successively.
| Translated title of the contribution | Study of free convection in homogeneous and binary systems |
|---|---|
| Original language | Polish |
| Pages (from-to) | 425-432 |
| Number of pages | 8 |
| Journal | Prace Naukowe Instytutu Techniki Cieplnej i Mechaniki Plynow Politechniki Wroclawskiej |
| Issue number | 53 |
| Publication status | Published - 1998 |
| Externally published | Yes |