نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشکده علوم و فنون نوین دانشگاه تهران
2 گروه هوافضا، دانشکدگان علوم و فناوریهای میانرشتهای، دانشگاه تهران، تهران، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Rotating systems such as axial flow fans and wind turbines are essential components in modern engineering applications, serving crucial roles in cooling processes, ventilation, and the production of clean and sustainable energy. Despite their importance, one of the most persistent challenges associated with their operation is the generation of aerodynamic noise. This noise often originates from complex flow instabilities, with tip-leakage vortices and unsteady interactions near the blade tips being among the dominant sources. Such noise not only reduces the efficiency and reliability of these systems but also poses environmental and health concerns, particularly in urban and residential settings where noise exposure is critical. As a result, the development of effective noise-reduction strategies has become a pressing necessity in both industrial and academic research.
Recent studies have highlighted the potential of porous casings as a passive and practical solution for mitigating aeroacoustic emissions. In this context, the present study investigates porous structures based on Triply Periodic Minimal Surfaces (TPMS), which are known for their unique geometric features, high surface area, and tunable porosity. Initially, the acoustic performance of several TPMS configurations was examined by calculating their sound absorption coefficients. Among the designs, the Gyroid structure with 50% porosity was identified as the most effective due to its balance of acoustic damping and mechanical integrity.
The selected design was subsequently implemented in two representative case studies: the casing of an axial flow fan and the duct surrounding a ducted wind turbine. A comprehensive methodology combining high-fidelity numerical simulations and experimental validation was employed to capture both aerodynamic characteristics and underlying mechanisms of noise generation and suppression.
Results clearly demonstrate that TPMS-based porous casings weaken the strength and scale of tip-leakage vortices and reduce turbulence intensity near the casing wall. Furthermore, they effectively attenuate tonal noise associated with the blade passing frequency as well as broadband noise caused by turbulence interactions. Quantitatively, the approach achieved a 6 dB reduction (≈11%) in the axial fan, alongside a 36% decrease in accumulated acoustic energy. For the ducted wind turbine, an 8% reduction in overall sound pressure level (OASPL) was observed.
These findings confirm that TPMS-based porous casings represent a novel and efficient aeroacoustic treatment, offering significant potential for reducing noise in rotating machinery without compromising aerodynamic performance.
کلیدواژهها [English]
)