Carlos Alberto Duque Daza

Digitalización 3d del rodete de un compresor centrífugo:un procedimiento alternativo

In the 3D digitizing of an HT3B turbocharger’s centrifugal compressor’s impeller, several methodologies were evaluated, reproducing its shape in such a way, that the obtained virtual model could be used to perform a computational flow simulation in the whole centrifugal compressor. After analyzing these methodologies, computerized axial tomographies were chosen as the most suitable methodology, despite requiring the previous construction of an impeller’s acrylic-made model. Once the impeller’s computerized axial tomographies had been taken, the generation of the virtual model was performed by software CAD 3D, by integrating an analytic methodology for the impeller’s vanes’ geometrical shape generation, with the metrological information extracted from the tomographies. The virtual model generated presented characteristics which made it appropriate for the intended flow simulation, showing that the procedure used for this purpose constitutes a feasible alternative for the 3D digitizing of complex mechanical parts.

SIMULACIÓN BIDIMENSIONAL DE UN SISTEMA DE COMBUSTIÓN INESTABLE

The Combustion instability is an undesirable condition reached in some combustion systems, as during the operation of gas turbines. It refers to self-excited oscillations of pressure that may affect the combustion chamber and generate noise. A recent generalized tendency in combustion processes aims to the use of lean combustion (low fuel/air ratios) for pollutants reduction, nevertheless this sort of mixtures are more susceptible to combustion instabilities. The complex relationship that generates the phenomenon can be summarized as the coupling between flame and acoustics. In this paper it is outlined a numerical approach to this phenomenon by solving a basic computational combustion model (by Direct Numerical Simulation). In this model a self-excited system is simulated through imposed oscillations in reactants flows. Finally, results for this numerical simulation are compared against other simulations and experimental available data.

SIMULACIÓN 3D DEL FLUJO EN UN COMPRESOR CENTRÍFUGO POR MEDIO DE HERRAMIENTAS CFD BAJO CARGA PARCIAL

This article presents the procedure followed to simulate the air flow in a HOLSET HT3B centrifugal compressor using FLUENT® and GAMBIT®, both CFD (Computer Fluid Dynamics) packages, which are based on the finite volume technique. Initially some important considerations will be presented, which must be considered when using the CFD tools for the flow simulation; later, the simulation process will be described to obtain the first results, and their most relevant characteristics will be discussed briefly. It is important to mention that this article makes reference to the initial simulation of the flow in the mentioned compressor, and that some recommendations for the operational parameters adjustments are presented as a plus