Shape optimization of annular S-ducts by CFD and high-order polynomial response surfaces. Issue 2 (16th April 2018)

• Record Type: Journal Article
• Authors: Immonen, Eero
• Is Part Of: Engineering computations. Volume 35:Issue 2(2018)
• Page Start: 932
• Page End: 954
• Publication Date: 2018-04-16
• Subjects: CFD -- Multi-objective -- Shape optimization -- Axisymmetric -- Response surface model -- S-duct; Computer-aided engineering -- Periodicals; Computer graphics -- Periodicals; 620.00285
• DOI: 10.1108/EC-08-2017-0327
• Languages: English
• ISSNs: 0264-4401

Abstract

Abstract : Purpose: This paper aims to design an optimal shape for an annular S-duct, considering both energy losses and exit flow uniformity, starting from a given baseline design. Moreover, this paper seeks to identify the design factors that affect the optimal annular S-duct designs. Design/methodology/approach: The author has carried out computational fluid dynamic (CFD)-based shape optimization relative to five distinct numerical objectives, to understand their interrelations in optimal designs. Starting from a given baseline S-duct design, they have applied control node-induced shape deformations and high-order polynomial response surfaces for modeling the functional relationships between the shape variables and the numerical objectives. A statistical correlation analysis is carried out across the optimal designs. Findings: The author has shown by single-objective optimization that the two typical goals in S-duct design, energy loss minimization and exit flow uniformity, are mutually contradictory. He has presented a multi-objective solution for an optimal shape, reducing the total pressure loss by 15.6 per cent and the normalized absolute radial exit velocity by 34.2 per cent relative to a baseline design. For each of the five numerical objectives, the best optimization results are obtained by using high-order polynomial models. Research limitations/implications: The methodology is applicable to axisymmetric two-dimensional geometry models. Originality/value: This paper applies a recently introduced shape optimization methodology to annular S-ducts, and, it is, to the author's knowledge, the first paper to point out that the two widely studied design objectives for annular S-ducts are contradictory. This paper also addresses the value of using high-order polynomial response surface models in CFD-based shape optimization.