Lanxi Zhang¹, Yuming Peng¹, Yudong Wu^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.1, pp. 205-220, 2025, DOI:10.32604/fdmp.2024.056516 - 24 January 2025

Abstract The challenge of aerodynamic noise is a key obstacle in the advancement of low-pressure tube ultra-high-speed maglev transportation, demanding urgent resolution. This study utilizes a broadband noise source model to perform a quantitative analysis of the aerodynamic noise produced by ultra-high-speed maglev trains operating in low-pressure environments. Initially, an external flow field calculation model for the ultra-high-speed maglev train is presented. Subsequently, numerical simulations based on the broadband noise source model are used to examine the noise characteristics. The impact of the train speed and pressure level on noise generation is investigated accordingly. Subsequently, a… More >

Baohua Li, Yi Ye, Yuanjun Dai^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.12, pp. 2809-2842, 2024, DOI:10.32604/fdmp.2024.054011 - 23 December 2024

Abstract A linear microporous blade tip structure is designed in order to reduce the aerodynamic noise of a wind turbine during operations. Various structures of such a kind are considered and the related aerodynamic noise is determined in the framework of large vortex simulation and acoustic array test methods. The findings demonstrate that various blade tip designs can enhance the vortex trajectory in the tip region and lessen the pressure differential between the blade’s upper and lower surfaces. In particular, the wind turbine’s maximum linear velocity at the blade tip can be increased by 10%–23% while More > Graphic Abstract

Haitao Liu^1,2,*, Jiaming Wang¹, Xiuliang Zhang¹, Yanji Jiang², Qian Xiao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2747-2772, 2024, DOI:10.32604/cmes.2024.047129 - 11 March 2024

Abstract The expansion chamber serves as the primary silencing structure within the exhaust pipeline. However, it can also act as a sound-emitting structure when subjected to airflow. This article presents a hybrid method for numerically simulating and analyzing the unsteady flow and aerodynamic noise in an expansion chamber under the influence of airflow. A fluid simulation model is established, utilizing the Large Eddy Simulation (LES) method to calculate the unsteady flow within the expansion chamber. The simulation results effectively capture the development and changes of the unsteady flow and vorticity inside the cavity, exhibiting a high… More > Graphic Abstract

Deng Qin¹, Xing Du², Tian Li^1,*, Jiye Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 2155-2173, 2024, DOI:10.32604/cmes.2023.044460 - 29 January 2024

Abstract Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly, energy efficient and rapid advances in train technology. Using computational fluid dynamics theory and the K-FWH acoustic equation, a numerical simulation is conducted to investigate the aerodynamic characteristics of high-speed pantographs. A component optimization method is proposed as a possible solution to the problem of aerodynamic drag and noise in high-speed pantographs. The results of the study indicate that the panhead, base and insulator are the main contributors to aerodynamic drag and noise in high-speed pantographs. Therefore, a gradual… More >

Jiawei Shi, Jiye Zhang^*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 2175-2195, 2024, DOI:10.32604/cmes.2023.043539 - 29 January 2024

Abstract Combining the detached eddy simulation (DES) method and Ffowcs Williams-Hawkings (FW-H) equation, the effect of bogie cavity end wall inclination on the flow field and aerodynamic noise in the bogie region is numerically studied. First, the simulation is conducted based on a simplified cavity-bogie model, including five cases with different inclination angles of the front and rear walls of the cavity. By comparing and analyzing the flow field and acoustic results of the five cases, the influence of the regularity and mechanism of the bogie cavity end wall inclination on the flow field and the… More >

Baohua Li¹, Yuanjun Dai^1,2,*, Jingan Cui¹, Cong Wang¹, Kunju Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.12, pp. 3033-3043, 2023, DOI:10.32604/fdmp.2023.029583 - 27 October 2023

Abstract To reduce the vibration and aerodynamic noise of wind turbines, a new design is proposed relying on a blade with a bifurcated apex or tip. The performances of this wind turbine wheel are tested at the entrance of a DC (directaction) wind tunnel for different blade tip angles and varying centrifugal force and aerodynamic loads. The test results indicate that the bifurcated apex can reduce the vibration acceleration amplitude and the vibration frequency of the wind wheel. At the same time, the bifurcated apex can lower the maximum sound pressure level corresponding to the rotating More >

Jun Feng^1,2, Tao Bian^1,2,5, Qianpeng Han², Bing Wang^1,3,4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 1-14, 2023, DOI:10.32604/fdmp.2023.018275 - 02 August 2022

Abstract The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level (OASPL). The results demonstrate that when the circular rings cover near 2/3 of the width of the blade tips of the rotor in the axis direction, the rotor has the lowest OASPL and the related total pressure efficiency and flow mass rate are better than the corresponding values obtained for a reference rotor without a circular ring. With increasing the width of the circular ring More > Graphic Abstract

Deng Qin¹, Tian Li^1,*, Honglin Wang², Jizhong Yang³, Yao Jiang³, Jiye Zhang¹, Haiquan Bi²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.3, pp. 1371-1386, 2022, DOI:10.32604/cmes.2022.018480 - 30 December 2021

Abstract The aerodynamic noise of high-speed trains passing through a tunnel has gradually become an important issue. Numerical approaches for predicting the aerodynamic noise sources of high-speed trains running in tunnels are the key to alleviating aerodynamic noise issues. In this paper, two typical numerical methods are used to calculate the aerodynamic noise of high-speed trains. These are the static method combined with non-reflective boundary conditions and the dynamic mesh method combined with adaptive mesh. The fluctuating pressure, flow field and aerodynamic noise source are numerically simulated using the above methods. The results show that the More >

Jiawei Shi¹, Shuai Ge¹, Xiaozhen Sheng^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 463-480, 2022, DOI:10.32604/fdmp.2022.017508 - 16 December 2021

Abstract In order to understand the mechanism by which a pantograph can generate aerodynamic noise and grasp its far-field characteristics, a simplified double-strip pantograph is analyzed numerically. Firstly, the unsteady flow field around the pantograph is simulated in the frame of a large eddy simulation (LES) technique. Then the location of the main noise source is determined using surface fluctuating pressure data and the vortex structures in the pantograph flow field are analyzed by means of the Q-criterion. Based on this, the relationship between the wake vortex and the intensity of the aerodynamic sound source on… More >

Lin Wang¹, Chunguo An², Nini Wang², Yaming Ping¹, Kun Wang¹, Ming Gao^1,*, Suoying He¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 585-600, 2020, DOI:10.32604/fdmp.2020.09611 - 25 May 2020

Abstract Numerical simulation are conducted to explore the characteristics of the axial inflow and related aerodynamic noise for a large-scale adjustable fan with the installation angle changing from −12° to 12°. In such a range the maximum static (gauge) pressure at the inlet changes from −2280 Pa to 382 Pa, and the minimum static pressure decreases from −3389 Pa to −8000 Pa. As for the axial intermediate flow surface, one low pressure zone is located at the junction of the suction surface and the hub, another is located at the suction surface close to the casing… More >