关键词: 异构计算, 涵道风扇, 流固耦合, 颤振, 间隙失谐, 模态局部化

Abstract: For ducted fans with aerodynamic mistuning, the conventional spatial truncation model based on a fixed nodal-diameter assumption cannot be used to characterize mode-localized responses, and is therefore insufficient for accurately evaluating flutter stability. To overcome this limitation, this study employs a time-domain fluid–structure coupled method to analyze the flutter behavior. To reduce the high computational cost of fluid–structure coupled analyses, a GPU-accelerated heterogeneous parallel framework is proposed. Compared with 96-core CPU computation, the proposed framework achieves a speedup factor of 47 in wall-clock time using eight GPU cards, while its monetary computing cost is only 5.2% of that of the CPU-based computation. Based on this framework, fluid–structure coupled flutter analyses are performed for a ducted fan under uniform tip clearance and tip-clearance mistuning conditions. The results show that non-uniform tip clearance significantly alters the unsteady aerodynamic coupling among blades, leading to a more non-uniform distribution of vibrating energy, inducing mode localization, and worsening the aeroelastic instability. These findings further demonstrate that full-annulus time-domain fluid–structure coupled analysis can effectively capture local aeroelastic response characteristics under rotor geometric mistuning, providing an effective approach for flutter stability assessment of mistuned fans.

Key words: heterogeneous computing, ducted fan, fluid-structure interaction, flutter, tip-clearance mistuning, mode localization