On the modeling of flow regimes and thermal patterns interactions in complex applications

الملخص EN

The recent advances in numerical methods and the vast development of computers had directed the designers to better development and modifications to airflow pattern and heat transfer in complex geometries such as combustion chambers, aluminum reductions cells and air conditioned operating theatres.

The Present work fosters mathematical modeling techniques to primarily predict what happens in three-dimensional complex geometries and presents a summary of its status quo.

Applications include, among others, combustion chambers, aero engines in terms of flow regimes and interactions.

It also includes predictions of flow and heat transfer in Aluminum reduction pots where the pot is full with the molten metal and electrolyte in the anodes-cathode void.

Magnetic field and forces would result in molten metal movement, stirring and consequently possible re-oxidation of aluminum at anode surfaces causing low productivity.

The flow in air-conditioned operating theatres is also addressed in this paper.

The present work is generally devoted to demonstrate the effect of design and operational parameters on performance of such systems.

The governing equations of mass, momentum, species and energy are commonly expressed in a general finite difference form to be solved with the aid of SIMPLE Algorithm.

The results are obtained in this work with the aid of the three-dimensional program ; applied to axe symmetrical and three-dimensional complex geometries.

The present numerical grid comprises, typically, 80 x 60 x 30-grid mesh of total 144000-grid node covering the volume in the X, R or Y and Z coordinates directions.

The numerical residual in the governing equations are typically less than 0.001 %.

The obtained results include velocity vectors, turbulence intensities, temperatures and wall heat fluxes.

Flow regimes and heat transfer were found to be strongly dependent on turbulent shear, mixing, blockages, wall conditions and inlet conditions.

Examples of large industrial furnaces, reduction cells and operating theatres are shown and are in good agreement with available measurements in the open literature.

One may conclude that flow patterns, turbulence and heat transfer in complex geometries are strongly affected by the inlet and boundary conditions ; both micro and macro mixing levels are influential.

The present modeling capabilities can adequately predict the local flow pattern and turbulence kinetic energy levels in complex geometries.