Shape optimization of a bidirectional impulse turbine via surrogate models

ABSTRACT In this work, a bidirectional impulse turbine used in a wave energy device is simulated using a CFD technique and a shape optimization performed with multiple surrogates-assisted multi-objective evolutionary algorithm. The surrogates have been generated using the validated CFD technique. The objectives for the optimization are to maximize the shaft power and to minimize the pressure drop across the turbine. The hub and the tip thickness of the rotor blade profiles are modified and considered as the design variables. The Latin hypercube sampling technique generated design points are evaluated in the CFD solver, the objective responses are used to construct multiple surrogates, and a Pareto optimal front is generated through a multi-objective optimization approach. The turbine efficiency, which is the function of pressure drop and shaft power, is relatively increased by 10.4%. Abbreviations: BPS: best PRESS; GV: Guide vane; KRG: kriging; LE: leading edge; MOO: multi-objective optimization; OWC: oscillating water column; PRESS: predicted error sum of squares; PS: pressure side or pressure surface; RB: rotor blade; RBNN: radial basis neural network; Ref: reference; RMS: root mean square; RSA: response surface approximation; SS: suction side or suction surface; TE: trailing edge; WAS: weighted average surrogates

[1]  Christophe Sarraf,et al.  Thickness effect of NACA foils on hydrodynamic global parameters, boundary layer states and stall establishment , 2010 .

[2]  Douglas C. Montgomery,et al.  Response Surface Methodology: Process and Product Optimization Using Designed Experiments , 1995 .

[3]  Kwang-Yong Kim,et al.  Multiple surrogate modeling for axial compressor blade shape optimization , 2008 .

[4]  Felipe A. C. Viana,et al.  Multiple surrogates for prediction and optimization , 2011 .

[5]  Timothy M. Mauery,et al.  COMPARISON OF RESPONSE SURFACE AND KRIGING MODELS FOR MULTIDISCIPLINARY DESIGN OPTIMIZATION , 1998 .

[6]  R. Haftka,et al.  Multiple surrogates: how cross-validation errors can help us to obtain the best predictor , 2009 .

[7]  R. K. Ursem.  Multi-objective Optimization using Evolutionary Algorithms , 2009 .

[8]  Timothy W. Simpson,et al.  Metamodeling in Multidisciplinary Design Optimization: How Far Have We Really Come? , 2014 .

[9]  Kwang-Yong Kim,et al.  Enhanced multi-objective optimization of a microchannel heat sink through evolutionary algorithm coupled with multiple surrogate models , 2010 .

[10]  A. Thakker,et al.  Experimental studies on effect of guide vane shape on performance of impulse turbine for wave energy conversion , 2005 .

[11]  C. L. Wu,et al.  Methods to improve neural network performance in daily flows prediction , 2009 .

[12]  R. J. Roelke,et al.  The Effect of Rotor Blade Thickness and Surface Finish on the Performance of a Small Axial Flow Turbine , 1983 .

[13]  Manabu Takao,et al.  Effects of hub-to-tip ratio and reynolds number on the performance of impulse turbine for wave energy power plant , 2003 .

[14]  Ying Cui,et al.  Numerical study on a modified impulse turbine for OWC wave energy conversion , 2016 .

[15]  A. Thakker,et al.  Computed effects of tip clearance on performance of impulse turbine for wave energy conversion , 2004 .

[16]  Ying Cui,et al.  Effects of Solidity Ratio on Performance of OWC Impulse Turbine , 2015 .

[17]  Kevin Tucker,et al.  Response surface approximation of pareto optimal front in multi-objective optimization , 2004 .

[18]  Farid Bakir,et al.  Experimental study of blade thickness effects on the overall and local performances of a Controlled Vortex Designed axial-flow fan , 2011 .

[19]  Manabu Takao,et al.  A review of impulse turbines for wave energy conversion , 2001 .

[20]  Abdus Samad,et al.  Multiple surrogate based optimization of a bidirectional impulse turbine for wave energy conversion , 2015 .

[21]  João C.C. Henriques,et al.  Multi-point aerodynamic optimization of the rotor blade sections of an axial-flow impulse air turbine for wave energy conversion , 2012 .

[22]  Manabu Takao,et al.  Effect of Blade Shape on the Performance of Wells Turbine for Wave Energy Conversion , 2015 .

[23]  Manabu Takao,et al.  Performance of an impulse turbine with fixed guide vanes for wave power conversion , 1999 .