Wavelet analysis on the turbulent flow structure of a T-junction
发布时间：2025-04-30
点击次数：
- 发布时间：
- 2025-04-30
- 论文名称：
- Wavelet analysis on the turbulent flow structure of a T-junction
- 发表刊物：
- International Journal of Heat and Fluid Flow
- 摘要：
- Wavelet Analysis on the Turbulent Flow Structure of a T-junction
Bo Su1, Yantao Yin1, Shicong Li1, Zhixiong Guo2, Qiuwang Wang1, Mei Lin1*
1. School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, China
2. Department of Mechanical and Aerospace Engineering, Rutgers, the State University of New Jersey, NJ 08854, USA
*Corresponding author: janeylinm@mail.xjtu.edu.cn
Tel and Fax: +86-29-82667936
Abstract: Experimental measurements in a T-junction with one inlet and two outlets mimicking the airflow in a high-speed train ventilation system were carried out using well-resolved Hot-Wire Anemometry (HWA). Continuous wavelet transform (CWT) is used to analyze the time-frequency contents of the instantaneous streamwise velocity; and the discrete wavelet transform (DWT) is employed to determine the multi-resolution energy characteristics. The measurements and analyses are carried out at three representative streamwise locations, i.e., upstream, mid-center, and downstream of the T-junction. The results show that the normalized time-average velocity at the mid-center of the T-junction is the largest near the wall region. Comparing the CWT data in the region near the wall, it is found that the dominant frequency of the periodic high energy coherent structures increases along the streamwise direction, and the wavelet energy magnitude at mid-center of T-junction decreases with the increase of velocity ratio. The DWT results show that apparent wavelet energy peak appears at the upstream and downstream of the T-junction for different scales from 26 to 210, but not at the mid-center. However, the energy at scale 211 abruptly rises in all flow regions at all the three streamwise locations and this energy decreases with the increase of the velocity ratio. Therefore, a higher velocity ratio is preferred for suppressing the generation of large-scale coherent structures to reduce drag forces and skin frictions for high-speed trains.
Keywords: Wavelet transform; T-junction; Turbulent structure; Fluctuating velocity.
- 合写作者：
- Bo Su, Yantao Yin, Shicong Li, Zhixiong Guo, Qiuwang Wang, Mei Lin
- 卷号：
- 73
- 页面范围：
- 124-142
- 是否译文：
- 否
- 发表时间：
- 2018-10-05