大涵道比风扇低噪声与颤振抑制设计方法研究

Research on low-noise and flutter suppression design method for high-bypass-ratio fan

  • 摘要: 为满足航空发动机风扇高负荷、低重量与低噪声的综合技术需求,突破大涵道比风扇降噪与减重的瓶颈,本文提出并开发了一种风扇低噪声与颤振抑制一体化设计方法。该方法将风扇低噪声设计与颤振抑制这两个常被独立处理的关键问题纳入统一设计流程进行协同优化。基于非线性谐波法进行风扇三维非定常流场数值模拟,并应用波分解方法评估激波诱导的单音噪声。通过将风扇叶片表面膨胀波波系控制、端弯及掠型设计等关键技术应用于大涵道比风扇设计,显著降低了风扇前传管道内的脉动压力,有效抑制了激波噪声;同时,显著提升了叶片颤振稳定性。研究结果表明:相较于基准风扇叶片,采用叶片表面波系优化、端弯与掠型复合设计的转子叶片,在设计转速风扇入口声压级降低达11.0 dB,起飞转速降低5.8 dB,降噪效果明显。此外,叶片应力水平显著降低,应力集中有效改善,气动阻尼大幅提升。本研究所提出的设计方法具有明确的工程应用前景,为大涵道比风扇的高性能设计提供了有效途径。

     

    Abstract: To address the comprehensive technical requirements of high loading, low weight and low noise for aero-engine fans, and to break through the bottleneck of noise reduction and weight reduction for high-bypass-ratio fans, this paper proposes and develops an integrated design method for low noise and flutter suppression of fans. This method incorporates the two key issues of fan low noise design and flutter suppression, which are usually treated independently, into a unified design process for collaborative optimization. Based on the nonlinear harmonic method (NLH), three-dimensional unsteady flow field numerical simulation of the fan is conducted, and the wave decomposition method is applied to evaluate the tonal noise induced by shock waves. By applying key techniques such as controlling expansion wave systems on the blade surface, end-bending, and swept design to the high-bypass-ratio fan design, the pulsating pressure in the fan inlet duct is significantly reduced, and shock wave noise is effectively suppressed; at the same time, the flutter stability of the blades is significantly improved. The results demonstrate that, compared to the baseline fan blade, the rotor blade optimized with wave system control, end-bending, and swept design achieved a reduction of up to 11.0 dB in sound pressure level at the fan inlet at design speed and 5.8 dB at takeoff speed, indicating notable noise reduction effects. Additionally, blade stress was significantly reduced, stress concentration was effectively mitigated, and aerodynamic damping was substantially enhanced. The design methodology proposed in this study shows clear potential for engineering applications and provides an effective approach for high-performance design of high-bypass-ratio fans.

     

/

返回文章
返回