Abstract
Fluid entrainment is of particular significance for the applications of synthetic jets in flow control. We investigate the structure evolution and transient fluid entrainment by the vortex rings in turbulent synthetic jets. Two orifice configurations of circular and rectangular with the aspect ratio of 3 are examined at the same parameters. Time-resolved tomographic particle image velocimetry is used to acquire the three-dimensional flow field information. The analysis based on Lagrangian coherent structures is used to visualize topology deformation of the vortex ring, describe mass transport and quantify entrainment by successive vortex rings. Particularly, the traditional method of the moving reference frame of the vortex ring cannot be effectively applied to the rectangular case due to non-uniform azimuthal translational velocity on the vortex ring. A new approach based on identifying the vortex boundaries by the finite-time Lyapunov exponent ridges is adopted to estimate the volume of the vortex bubble and thus to calculate entrainment and kinetic energy fractions. The results show that the rectangular case generally entrains more ambient fluids, resulting in larger vortex strength than the circular case. Furthermore, more kinetic energy from the ejected fluids is absorbed by the rectangular case to sustain the axis switching of the vortex ring. That could be beneficial for jet mixing enhancement. The current study develops the mathematic description of the dynamics of vortex rings, which can provide an important reference for quantifying fluid entrainment by the vortex rings in flow control applications.
摘要
旋涡卷吸特性对合成射流的流动控制应用具有重要意义. 为了研究湍流合成射流涡环的结构演化和瞬态卷吸特性, 采用时间解析层析粒子图像测速技术, 测量了相同参数下, 圆形和长宽比为3的矩形合成射流的三维流场. 利用拉格朗日拟序结构方法, 刻画了涡环的三维拓扑变形和质量输运过程, 并量化了连续涡环的卷吸特性. 特别是对矩形涡环, 由于涡环的对流速度沿周向分布不均匀, 导致传统的移动参考系方法无法有效计算卷吸. 针对该问题, 采用基于有限时间李雅普诺夫指数“脊线”辨识旋涡边界的方法, 估计涡泡体积, 从而计算涡环的卷吸和动能转换效率. 结果表明, 矩形涡环能够卷吸更多的周围流质, 产生比圆形涡环更大的涡旋强度; 此外, 矩形涡环从孔口喷出的流质中获得了更多动能, 以维持涡环的轴系转换, 这些特征有利于增强射流掺混. 上述工作通过发展旋涡动力学的数学描述, 为量化流动控制中的旋涡卷吸特性提供了重要参考.
References
W. He, Z. Luo, X. Deng, P. Cheng, W. Peng, Y. Zhou, S. Li, and T. Gao, Alleviation of self-support in dual synthetic jet and its self-similarity of streamwise momentum flux, Phys. Fluids 34, 097108 (2022).
X. Wen, H. Tang, and F. Duan, Interaction of in-line twin synthetic jets with a separated flow, Phys. Fluids 28, 043602 (2016).
Q. Xia, and S. Zhong, A PLIF and PIV study of liquid mixing enhanced by a lateral synthetic jet pair, Int. J. Heat Fluid Flow 37, 64 (2012).
R. Holman, Y. Utturkar, R. Mittal, B. L. Smith, and L. Cattafesta, Formation criterion for synthetic jets, AIAA J. 43, 2110 (2005).
J. E. Cater, and J. Soria, The evolution of round zero-net-mass-flux jets, J. Fluid Mech. 472, 167 (2002).
B. L. Smith, and G. W. Swift, A comparison between synthetic jets and continuous jets, Exp. Fluids 34, 467 (2003).
J. M. Shuster, and D. R. Smith, Experimental study of the formation and scaling of a round synthetic jet, Phys. Fluids 19, 045109 (2007).
M. Jabbal, J. Wu, and S. Zhong, The performance of round synthetic jets in quiescent flow, Aeronaut. J. 110, 385 (2006).
A. McGuinn, R. Farrelly, T. Persoons, and D. B. Murray, Flow regime characterisation of an impinging axisymmetric synthetic jet, Exp. Thermal Fluid Sci. 47, 241 (2013).
E. J. Gutmark, and F. F. Grinstein, Flow control with noncircular jets, Annu. Rev. Fluid Mech. 31, 239 (1999).
F. F. Grinstein, Vortex dynamics and entrainment in rectangular free jets, J. Fluid Mech. 437, 69 (2001).
K. B. M. Q. Zaman, Axis switching and spreading of an asymmetric jet: The role of coherent structure dynamics, J. Fluid Mech. 316, 1 (1996).
A. Ghasemi, B. A. Tuna, and X. Li, Curvature-induced deformations of the vortex rings generated at the exit of a rectangular duct, J. Fluid Mech. 864, 141 (2019).
J. C. Straccia, and J. A. N. Farnsworth, Axis switching in low to moderate aspect ratio rectangular orifice synthetic jets, Phys. Rev. Fluids 6, 054702 (2021).
F. F. Grinstein, and C. R. DeVore, Dynamics of coherent structures and transition to turbulence in free square jets, Phys. Fluids 8, 1237 (1996).
A. Ghasemi, V. Roussinova, R. M. Barron, and R. Balachandar, Large eddy simulation of the near-field vortex dynamics in starting square jet transitioning into steady state, Phys. Fluids 28, 085104 (2016).
M. Amitay, and F. Cannelle, Evolution of finite span synthetic jets, Phys. Fluids 18, 054101 (2006).
T. Van Buren, E. Whalen, and M. Amitay, Vortex formation of a finite-span synthetic jet: Effect of rectangular orifice geometry, J. Fluid Mech. 745, 180 (2014).
L. Wang, L. H. Feng, J. J. Wang, and T. Li, Evolution of low-aspect-ratio rectangular synthetic jets in a quiescent environment, Exp Fluids 59, 91 (2018).
L. Wang, L. H. Feng, and Y. Xu, Laminar-to-transitional evolution of three-dimensional vortical structures in a low-aspect-ratio rectangular synthetic jet, Exp. Thermal Fluid Sci. 104, 129 (2019).
A. Hashiehbaf, and G. P. Romano, A phase averaged PIV study of circular and non-circular synthetic turbulent jets issuing from sharp edge orifices, Int. J. Heat Fluid Flow 82, 108536 (2020).
J. O. Dabiri, and M. Gharib, Fluid entrainment by isolated vortex rings, J. Fluid Mech. 511, 311 (2004).
R. Sau, and K. Mahesh, Passive scalar mixing in vortex rings, J. Fluid Mech. 582, 449 (2007).
Y. Qu, J. Wang, L. Feng, and X. He, Effect of excitation frequency on flow characteristics around a square cylinder with a synthetic jet positioned at front surface, J. Fluid Mech. 880, 764 (2019).
L. Wang, and L. H. Feng, Dynamics of the interaction of synthetic jet vortex rings with a stratified interface, J. Fluid Mech. 943, A1 (2022).
X. Wen, H. Tang, and F. Duan, Vortex dynamics of in-line twin synthetic jets in a laminar boundary layer, Phys. Fluids 27, 083601 (2015).
L. Lu, D. Li, Z. Gao, Z. Cao, Y. Bai, and J. Zheng, Characteristics of array of distributed synthetic jets and effect on turbulent boundary layer, Acta Mech. Sin. 36, 1171 (2020).
Q. Liu, Z. Luo, X. Deng, Y. Zhou, L. Wang, and P. Cheng, Vortical structures and density fluctuations analysis of supersonic forward-facing step controlled by self-sustaining dual synthetic jets, Acta Mech. Sin. 36, 1215 (2020).
B. L. Smith, and A. Glezer, The formation and evolution of synthetic jets, Phys. Fluids 10, 2281 (1998).
B. Wieneke, Volume self-calibration for 3D particle image velocimetry, Exp. Fluids 45, 549 (2008).
G. E. Elsinga, F. Scarano, B. Wieneke, and B. W. van Oudheusden, Tomographic particle image velocimetry, Exp. Fluids 41, 933 (2006).
F. Scarano, and M. L. Riethmuller, Advances in iterative multigrid PIV image processing, Exp. Fluids 29, S051 (2000).
C. Y. Wang, Q. Gao, H. P. Wang, R. J. Wei, T. Li, and J. J. Wang, Divergence-free smoothing for volumetric PIV data, Exp. Fluids 57, 15 (2016).
A. Sciacchitano, and B. Wieneke, PIV uncertainty propagation, Meas. Sci. Technol. 27, 084006 (2016).
H. Y. Zhu, C. Y. Wang, H. P. Wang, and J. J. Wang, Tomographic PIV investigation on 3D wake structures for flow over a wall-mounted short cylinder, J. Fluid Mech. 831, 743 (2017).
M. Dawoodian, and A. Sau, Kinetics and prey capture by a paddling jellyfish: Three-dimensional simulation and Lagrangian coherent structure analysis, J. Fluid Mech. 912, A41 (2021).
M. Zhang, Q. Wu, B. Huang, and G. Wang, Lagrangian-based numerical investigation of aerodynamic performance of an oscillating foil, Acta Mech. Sin. 34, 839 (2018).
H. Lin, Y. Xiang, H. Xu, H. Liu, and B. Zhang, Passive scalar mixing induced by the formation of compressible vortex rings, Acta Mech. Sin. 36, 1258 (2020).
J. S. Wang, and J. J. Wang, Vortex dynamics for flow around the slat cove at low Reynolds numbers, J. Fluid Mech. 919, A27 (2021).
R. Kumar, J. T. King, and M. A. Green, Three-dimensional pitching panel wake: Lagrangian analysis and momentum distribution from experiments, AIAA J. 57, 3701 (2019).
B. Steinfurth, and J. Weiss, Vortex rings produced by non-parallel planar starting jets, J. Fluid Mech. 903, A16 (2020).
T. Maxworthy, The structure and stability of vortex rings, J. Fluid Mech. 51, 15 (1972).
J. S. Wang, and J. J. Wang, Wake-induced transition in the low-Reynolds-number flow over a multi-element airfoil, J. Fluid Mech. 915, A28 (2021).
Q. Wu, B. Huang, and G. Wang, Lagrangian-based investigation of the transient flow structures around a pitching hydrofoil, Acta Mech. Sin. 32, 64 (2016).
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant Nos. 12102029, 11902019 and 11721202), and the Postdoctoral Science Foundation Grant of China (Grant No. 2021M690301).
Author information
Authors and Affiliations
Corresponding author
Additional information
Author contributions
Lei Wang designed the research and developed the methodology. Lei Wang and Yang Xu wrote the first draft of the manuscript. Lei Wang and Yang Xu set up the experiment set-up and processed the experiment data. Lihao Feng helped organize the manuscript. Lei Wang and Lihao Feng revised and edited the final version.
Rights and permissions
About this article
Cite this article
Wang, L., Feng, L. & Xu, Y. Lagrangian analysis on structure evolution and mass transport of circular and noncircular turbulent synthetic jets. Acta Mech. Sin. 39, 322294 (2023). https://doi.org/10.1007/s10409-022-22294-x
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s10409-022-22294-x