Multi-objective optimization for centrifugal compressor of mini turbojet engine

This paper presents design optimization of a centrifugal compressor impeller with hybrid multi-objectives evolutionary algorithm (hybrid MOEA). Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model are discretized by finite volume approximations and solved on hexahedral grids for flow analyses. Latin hypercube sampling of design of experiments is used to generate design points within the selected design space. Two objectives, i.e., isentropic efficiency and total pressure ratio are selected with four design variables defining impeller hub and shroud contours in meridional contours to optimize the system. Non-dominated Sorting of Genetic Algorithm (NSGA-II) with ε-constraint strategy for local search coupled with surrogate model is used for multi-objective optimization. The surrogate model, Radial Basis Neural Network is trained on the numerical solutions by carrying out leave-one-out cross-validation for the data set. The trade-off between the two objectives has been found out and discussed in light of the Pareto-optimal solutions. The optimization results show that isentropic efficiencies and total pressure ratios of the cluster points at the Pareto-optimal solutions are enhanced by multi-objective optimization.

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Intelligence design method for three-dimensional vaned diffusers in a centrifugal compressor

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650917750713 ◽

2018 ◽

Vol 232 (6) ◽

pp. 674-690 ◽

Cited By ~ 1

Author(s):

Jian Wang ◽

Suping Wen ◽

Wenbo Wang ◽

Guang Xi

Keyword(s):

Mathematical Model ◽

Centrifugal Compressor ◽

Design Space ◽

Design Method ◽

Three Dimensional ◽

Design Model ◽

Centrifugal Impeller ◽

Multi Objective Optimization ◽

Vaned Diffuser ◽

Multi Objective

This paper presents a multi-objective optimization-based intelligence design method for the design of the three-dimensional vaned diffuser for a given centrifugal compressor. This design method consists of three-dimensional vaned diffuser design model and its solving strategy. The three-dimensional vaned diffuser design model consists of the diffuser geometry mathematical model, performance evaluation model, objective equation, and design space. The diffuser geometry is described by the mathematical model of the meridional configurations and vane camber, trailing edge lean, and thickness. The generic design space is determined through literature statistical investigation. An NSGA-II multi-objective optimization algorithm, utilized to solve the three-dimensional vaned diffuser design model, directs the diffuser geometry variables to achieve the maximum stage isentropic efficiency and static pressure ratio at the design point within the design space automatically and intelligently. The presented three-dimensional vaned diffuser design method is demonstrated using a case test for a centrifugal impeller. The convergence of evolutionary solving for this three-dimensional vaned diffuser model is analyzed in detail, which provides the convergence reference for engineering applications. Three representative three-dimensional vaned diffusers on Pareto front are utilized to check the diversity of geometry shape and overall range performance characteristics. The results show that the three-dimensional vaned diffuser design method established here has excellent potential in automated design and maximizing stage performance. The method reported here could provide a valuable reference for the intelligent design of radial turbomachinery diffusers.

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