Purpose

This study aims to complete the optimization design of a centrifugal impeller with both high aerodynamic efficiency and good structural machinability.

Design/methodology/approach

First, the design parameters were derived from the blade loading distribution and the meridional geometry in the impeller three-dimensional (3D) inverse design. The blade wrap angle at the middle span surface and the spanwise averaged blade angle at the blade leading edge obtained from inverse design were chosen as the machinability objectives. The aerodynamic efficiency obtained by computational fluid dynamics was selected as the aerodynamic performance objective. Then, using multi-objective optimization with the optimal Latin hypercube method, quadratic response surface methodology and the non-dominated sorting genetic algorithm, the trade-off optimum impellers with small blade wrap angles, large blade angles and high aerodynamic efficiency were obtained. Finally, computational fluid dynamics and computer-aided manufacturing were performed to verify the aerodynamic performance and structural machinability of the optimum impellers.

Findings

Providing the fore maximum blade loading distribution at both the hub and shroud for the 3D inverse design helped to promote the structural machinability of the designed impeller. A straighter hub coupled with a more curved shroud also facilitated improvement of the impeller’s structural machinability. The preferred impeller was designed by providing both the fore maximum blade loading distribution at a relatively straight hub and a curved shroud for 3D inverse design.

Originality/value

The machining difficulties of the designed high-efficiency impeller can be reduced by reducing blade wrap angle and enlarging blade angle at the beginning of impeller design. It is of practical value in engineering by avoiding the follow-up failure for the machining of the designed impeller.

中文翻译：

---

兼顾气动效率和结构可加工性的离心叶轮多目标优化设计

目的

本研究旨在完成具有高气动效率和良好结构可加工性的离心叶轮的优化设计。

设计/方法/方法

首先，设计参数源自叶轮三维 (3D) 逆向设计中的叶片载荷分布和子午几何形状。选择逆向设计得到的中跨表面叶片包角和叶片前缘翼展平均叶片角度作为可加工性目标。选择计算流体动力学获得的气动效率作为气动性能目标。然后，采用最优拉丁超立方法、二次响应面法和非支配排序遗传算法进行多目标优化，得到小叶片包角、大叶片角度和高气动效率的权衡最优叶轮。最后，

发现

为 3D 逆向设计在轮毂和护罩处提供前最大叶片载荷分布有助于提高设计叶轮的结构可加工性。更直的轮毂与更弯曲的护罩相结合也有助于改进叶轮的结构可加工性。首选的叶轮是通过在相对直的轮毂处提供前最大叶片载荷分布和用于 3D 反向设计的弯曲护罩来设计的。

原创性/价值

在叶轮设计之初，通过减小叶片包角和增大叶片角度，可以降低设计的高效叶轮的加工难度。避免了设计的叶轮加工的后续故障，具有工程实用价值。