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J Glob Optim (2013) 55:729749
DOI 10.1007/s10898-012-0011-4
Galvn Sergio Rubio Carlos Jess Pacheco
Solorio Gildardo Carbajal Georgina
Received: 9 March 2011 / Accepted: 10 November 2012 / Published online: 5 December 2012 Springer Science+Business Media New York 2012
Abstract Computational Fluids Dynamics (CFD) tools guide engineers and designers to estimate the performance of new designs. However, a CFD analysis can be very time-consuming depending mainly on the grid size and domain complexity. Thus, this paper aims to describe the tools used to evaluate and compare the performance of different 3D draft tube models for reducing the time-effort needed in an optimization procedure. The results presented here, are the second part of an overall research to establish a global optimization methodology to improve the performance of an hydraulic draft tube through the inlet velocity prole. Previously, three steps of optimization methodology to minimize the energy losses were studied: the inlet velocity prole parameterization, the numerical optimization set-up and the objective function validation. In the latter step, a global optimization method called Multi Island Genetic Algorithm (MIGA) was considered, which requires a large number of iterations before producing a reliable result. This step is able to identify an efcient inlet velocity prole to minimize the energy losses through the draft tube model. However, each iteration is expensive in terms of computational time due to the need for 3D NavierStokes (NS) computations to evaluate each proles tness. Thus, in this work the methodology attempts to accelerate the optimization process with accurate results. In order to achieve the goal, the grid size of the 3D draft tube model was minimized, resulting in a much lower computational cost. Specifically, the draft tube calculations were performed on a sequence
G. Sergio (B) R. Carlos J. Pacheco S. Gildardo C. Georgina
Mechanical Engineering Department, Universidad Michoacana de Sn Nicols de Hidalgo, Apdo. Postal 588, CP 58000 Morelia, Michoacn, Mxicoe-mail: [email protected]
R. Carlose-mail: [email protected]
J. Pachecoe-mail: [email protected]
S. Gildardoe-mail: [email protected]
C. Georginae-mail: [email protected]
Optimization methodology assessment for the inlet velocity prole of a hydraulic turbine draft tube: part IIperformance evaluation of draft tube model
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of ve different grids each having approximately twice the number of elements compared to the previous. The measurements of the sensitivity of...