Fluid Topology optimization applied to laminar jet pumps.

Abstract

The continuous growth of environmental awareness by the public, industrial and political sectors create conditions for scientific advancements in technologies that contribute to confront climate change. In this context, ejector (or jet pumps) could be a promising device to reduce cost, complexity and energy consumption in processes where vacuum pumps, regular pumps or regular compressors are currently employed. However, despite several scientific publications since its conception, the low efficiency of jet pumps still is a limit factor to a broad range of applications. In the field of optimization, the relatively new branch of topology optimization is a powerful methodology that makes it possible to obtain novel designs without an initial guess. In the present work, the operation condition of a conventional jet pump was simplified, the resulting boundary conditions obtained from this simplification were submitted to topology optimization. The optimization methodology used was based in the literature. However, the number of iterations was increased when compared with the reference. The first round of results (with the same objective function and restriction of base article) pointed that, in some cases, the efficiency was benefited when the final geometry resembled a conventional ejector. In the face of the first-round results and the similarity with the heat sink optimization problem, the objective functions were enhanced with a second objective (multi-objective function) to capture the ejector physics completely. The results pointed that it is possible to increase in 102% the efficiency, compared to the single objective function results, with the correct parameters. Still, an alternative approach with different objective function and constraints was tested where the results indicated that both approaches were equivalent. Although the working conditions of the simulated ejector did not reflect the usual conditions, it was possible to investigate the objective functions and to establish an optimization methodology to the jet pump field. This way, the results obtained can be used as a basis from which future works in the jet pump field can take advantage.