Cyrus, Akili Elizabeth (2026) Numerical Study of Nozzle Geometry Effects on Three-Dimensional Offset Synthetic Jets. Masters thesis, Concordia University.
Preview |
Text (application/pdf)
3MBCyrus_MASc_S2026.pdf - Accepted Version Available under License Spectrum Terms of Access. |
Abstract
This study investigates the influence of nozzle geometry on the unsteady flow characteristics, vortex dynamics, and wall interactions of three-dimensional offset synthetic jets using improved delayed detached eddy simulations (IDDES). Simulations were conducted at a Reynolds number based on the maximum jet-exit velocity and nozzle diameter (d) of Re_0 = 580, and at a fixed actuation frequency of 300 Hz. Four nozzle geometries with identical cross-sectional area and an offset height of 2d from the wall were examined: circular, square, and rectangular nozzles with aspect ratios of AR = 3 and AR = 1/3. Instantaneous, phase-averaged, and time-averaged statistics, including the Q-criterion, were used to characterize the evolution of vortex rings, jet-wall attachment, and downstream wall synthetic jet development. The results show that all jets attached to the wall due to the Coandă effect, with the attachment length and mean decay rate decreasing for non-circular nozzles. Circular jets exhibited coherent vortex rings that persisted farther downstream, while square and rectangular jets underwent faster breakdown and enhanced turbulent mixing. Rectangular jets displayed axis switching, generating secondary spanwise vortices and promoting spanwise spreading of near-wall structures. The findings provide new insight into the effect of nozzle geometry in controlling vortex dynamics and wall interactions, with potential applications in the optimal design of offset synthetic jet actuators for enhanced mixing, heat transfer, and flow separation control in fluid-thermal engineering systems.
| Divisions: | Concordia University > Gina Cody School of Engineering and Computer Science > Mechanical, Industrial and Aerospace Engineering |
|---|---|
| Item Type: | Thesis (Masters) |
| Authors: | Cyrus, Akili Elizabeth |
| Institution: | Concordia University |
| Degree Name: | M.A. Sc. |
| Program: | Mechanical Engineering |
| Date: | 9 March 2026 |
| Thesis Supervisor(s): | Essel, Ebenezer Ekow |
| ID Code: | 997025 |
| Deposited By: | Akili Elizabeth Cyrus |
| Deposited On: | 29 Jun 2026 14:46 |
| Last Modified: | 29 Jun 2026 14:46 |
References:
[1] M. Jabbal and S. Zhong, “The near wall effect of synthetic jets in a boundary layer,” International Journal of Heat and Fluid Flow, vol. 29, no. 1, pp. 119–130, 2008, doi: https://doi.org/10.1017/S0001924000001305.[2] M. A. Feero, S. D. Goodfellow, P. Lavoie, and P. E. Sullivan, “Flow reattachment using synthetic jet actuation on a low reynolds number airfoil,” AIAA Journal, vol. 53, no. 7, pp. 1–26, 2014, doi: https://doi.org/10.1016/j.sna.2014.12.004.
[3] M. Arik and Y. V. Utturkar, “A computational and experimental investigation of synthetic jets for cooling of electronics,” Journal of Electronic Packaging, vol. 137, no. 2, p. 021005, 2015, doi: https://doi.org/10.1115/1.4029067.
[4] C. Xu, Y. Long, and J. Wang, “Entrainment mechanism of turbulent synthetic jet flow,” Journal of Fluid Mechanics, vol. 958, p. A31, 2023, doi: https://doi.org/10.1017/jfm.2023.102.
[5] A. Glezer and M. Amitay, “Synthetic Jets,” Annual Review of Fluid Mechchanics, vol. 34, pp. 503–529, 2001, doi: https://doi.org/10.1146/annurev.fluid.34.090501.094913.
[6] N. Chen and H. Yu, “Mechanism of axis switching in low aspect-ratio rectangular jets,” Computers and Mathematics with Applications, vol. 67, no. 2, pp. 437–444, 2014, doi: https://doi.org/10.1016/j.camwa.2013.03.018.
[7] R. Kotapati, R. Mittal, and N. L. Cattafesta, “Numerical study of a transitional synthetic jet in quiescent external flow,” Journal of Fluid Mechanics, vol. 581, pp. 287–321, 2007, doi: doi:10.1017/S0022112007005642.
[8] M. Jain, B. Puranik, and A. Agrawal, “A numerical investigation of effects of cavity and orifice parameters on the characteristics of a synthetic jet flow,” Sensors and Actuators, A: Physical, vol. 165, pp. 351–366, 2011, doi: https://doi.org/10.1016/j.sna.2010.11.001.
[9] H. Zong and M. Kotsonis, “Characterisation of plasma synthetic jet actuators in quiescent flow,” Journal of Physics D: Applied Physics, vol. 49, p. 335202, 2016, doi: 10.1088/0022-3727/49/33/335202.
[10] S. Carpy and R. Manceau, “Turbulence modelling of statistically periodic flows: Synthetic jet into quiescent air,” International Journal of Heat and Fluid Flow, vol. 27, no. 5, pp. 756-767, 2006, doi: https://doi.org/10.1016/j.ijheatfluidflow.2006.04.002.
[11] T. Van Buren, E. Whalen, and M. Amitay, “Vortex formation of a finite-span synthetic jet: Effect of rectangular orifice geometry,” Journal of Fluid Mechanics, vol. 745, pp. 180–207, 2014, doi: https://doi.org/10.1017/jfm.2014.77.
[12] L. Wang, L. H. Feng, J. J. Wang, and T. Li, “Evolution of low-aspect-ratio rectangular synthetic jets in a quiescent environment,” Experiments in Fluids, vol. 59, no. 91, pp. 1–16, 2018, doi: https://doi.org/10.1007/s00348-018-2544-x.
[13] H. H. Ho, E. E. Essel, and P. E. Sullivan, “The interactions of a circular synthetic jet with a turbulent crossflow,” Physics of Fluids, vol. 34, no. 7, p. 075108, 2022, doi: https://doi.org/10.1063/5.0099533.
[14] Y. Xu, C. Moon, J. J. Wang, O. G. Penyazkov, and K. C. Kim, “An experimental study on the flow and heat transfer of an impinging synthetic jet,” International Journal of Heat and Mass Transfer, vol. 144, p. 118626, 2019, doi: https://doi.org/10.1016/j.ijheatmasstransfer.2019.118626.
[15] J. Chang et al., “Investigation of Vortex Rings for Free Jet and Synthetic Jet at Various Reynolds Numbers and Strouhal Numbers,” Mathematical Problems in Engineering, vol. 2020, pp. 1–15, 2020, doi: https://doi.org/10.1155/2020/1503628.
[16] J. F. Li, X. B. Zhang, and T. H. New, “Formation and flow characteristics of low-Reynolds number synthetic jets,” Physics of Fluids, vol. 37, no. 3, p. 033631, 2025, doi: https://doi.org/10.1063/5.0259436.
[17] C. G. Ball, H. Fellouah, and A. Pollard, “The flow field in turbulent round free jets,” Progress in Aerospace Sciences, vol. 50, pp. 1–26, 2012, doi: https://doi.org/10.1016/j.paerosci.2011.10.002.
[18] C. D. Donaldson and R. S. Snedeker, Survey of Literature on Flow Characteristics of a Single Turbulent Jet Impinging on a Flat Plate. Washington, DC: National Aeronautics and Space Administration, 1971.
[19] B. L. Smith and G. W. Swift, “A comparison between synthetic jets and continuous jets,” Experiments in Fluids, vol. 34, no. 4, pp. 467–472, 2003, doi: https://doi.org/10.1007/s00348-002-0577-6.
[20] J. M. Shuster and D. R. Smith, “Experimental study of the formation and scaling of a round synthetic jet,” Physics of Fluids, vol. 19, no. 4, pp. 1–21, 2007, doi: https://doi.org/10.1063/1.2711481.
[21] J. Zhou, H. Tang, and S. Zhong, “Vortex roll-up criterion for synthetic jets,” AIAA Journal, vol. 47, no. 5, pp. 1252–1262, 2009, doi: https://doi.org/10.2514/1.40602.
[22] A. Hashiehbaf and G. P. Romano, “Particle image velocimetry investigation on mixing enhancement of non-circular sharp edge nozzles,” International Journal of Heat and Fluid Flow, vol. 44, pp. 208–221, 2013, doi: https://doi.org/10.1016/j.ijheatfluidflow.2013.05.017.
[23] L. Mangate, H. Yadav, A. Agrawal, and M. Chaudhari, “Experimental investigation on thermal and flow characteristics of synthetic jet with multiple-orifice of different shapes,” International Journal of Thermal Sciences, vol. 140, pp. 344–357, 2019, doi: https://doi.org/10.1016/j.ijthermalsci.2019.02.036.
[24] E. Smyk, J. Wilk, and M. Markowicz, “Synthetic jet actuators with the same cross-sectional area orifices-flow and acoustic aspects,” Applied Sciences (Switzerland, vol. 10, no. 11, pp. 1–14, 2019, doi: https://doi.org/10.3390/app11104600.
[25] A. Qayoum and A. Malik, “Influence of the Excitation Frequency and Orifice Geometry on the Fluid Flow and Heat Transfer Characteristics of Synthetic Jet Actuators,” Fluid Dynamics, vol. 54, no. 4, pp. 575–589, 2019, doi: https://doi.org/10.1134/S0015462819040086.
[26] L. Wang, L. H. Feng, J. J. Wang, and T. Li, “Parameter influence on the evolution of low-aspect-ratio rectangular synthetic jets,” Journal of Visualization, vol. 21, pp. 105–115, 2018, doi: https://doi.org/10.1007/s12650-017-0440-8.
[27] J. C. Straccia and J. A. Farnsworth, “Axis switching in low to moderate aspect ratio rectangular orifice synthetic jets,” Physical Review Fluids, vol. 6, no. 5, p. 054702, 2021, doi: https://doi.org/10.1103/PhysRevFluids.6.054702.
[28] M. Jabbal, J. Wu, and S. Zhong, “The performance of round synthetic jets in quiescent flow,” The Aeronautical Journal, vol. 110, no. 1108, pp. 385–393, 2006, doi: https://doi.org/10.1016/j.ijheatfluidflow.2007.07.011.
[29] S. Iio, T. Kawamura, M. Matsubara, T. Yoshida, and T. Ikeda, “Vortex Behavior of Pulsating Jets from a Rectangular Nozzle,” JSME International Journal, vol. 49, no. 4, pp. 988–994, 2006, doi: https://doi.org/10.1299/jsmeb.49.988.
[30] M. Agelin-Chaab and M. F. Tachie, “Characteristics and structure of turbulent 3D offset jets,” International Journal of Heat and Fluid Flow, vol. 32, no. 3, pp. 608–620, 2011, doi: https://doi.org/10.1016/j.ijheatfluidflow.2011.03.008.
[31] A. Cyrus, K. N. Hammond, and E. E. Essel, “Effects of Nozzle Geometry on Turbulent Characteristics of 3D Offset Synthetic Jets,” in THMT-25 Turbulence, Heat and Mass Transfer, Tokyo, Japan, 2025. doi: 10.1615/THMT-25.
[32] K. N. D. Hammond, M. O. Sandoval, N. Naeem, and E. E. Essel, “On the turbulent flow characteristics of wall-attaching synthetic jets at varying offset height ratios,” Physics of Fluids, vol. 37, no. 11, p. 115105, 2025, doi: https://doi.org/10.1063/5.0297258.
[33] A. Nasr and J. C. S. Lai, “A turbulent plane offset jet with small offset ratio,” Experiments in Fluids, vol. 24, pp. 47–57, 1998, doi: https://doi.org/10.1007/s003480050149.
[34] A. Assoudi, S. Habli, N. M. Saïd, H. Bournot, and G. L. Palec, “Experimental and numerical study of an offset jet with different velocity and offset ratios,” Engineering Applications of Computational Fluid Mechanics, vol. 9, no. 1, pp. 490–512, 2015, doi: https://doi.org/10.1080/19942060.2015.1071525.
[35] B. Nyantekyi-Kwakye, S. P. Clark, M. F. Tachie, M. Jarrod, and M. Getnet, “Flow characteristics within the recirculation region of three-dimensional turbulent offset jet,” Journal of Hydraulic Research, vol. 53, no. 2, pp. 230–242, 2014, doi: https://doi.org/10.1080/00221686.2014.950612.
[36] D. C. Wilcox, Turbulence modeling for CFD. San Diego: DCW Industries, 2006.
[37] H. K. Versteeg and W. Malalasekera, An Introduction to Computational Fluid Dynamics: The Finite Volume Method. London: Pearson Education, 2007. doi: https://doi.org/10.1063/1.1693899.
[38] Siemens, “STAR-CCM +User Guide,” Siemens, 2020.
[39] Pope S. B., Turbulent Flows. Ithaca: Cambridge University Press, 2000.
[40] I. Yoo and S. Lee, “Reynolds-averaged navier-stokes computations of synthetic jet flows using deforming meshes,” AIAA Journal, vol. 50, no. 9, pp. 1943–1955, 2012, doi: https://doi.org/10.2514/1.J051539.
[41] J. Cui and R. K. Agarwal, “Three-dimensional computation of a synthetic jet in quiescent air,” AIAA, vol. 44, no. 12, pp. 2857–2865, 2006, doi: https://doi.org/10.2514/1.14213.
[42] V. N. Vatsa and E. Turkel, “Simulation of synthetic jets using unsteady reynolds-averaged Navier-Stokes equations,” AIAA Journal, vol. 44, no. 2, pp. 217–224, 2006, doi: https://doi.org/10.2514/1.13535.
[43] F. R. Menter, “Two-equation eddy-viscosity turbulence models for engineering applications,” AIAA Journal, vol. 32, no. 8, pp. 1598–1605, 1994, doi: https://doi.org/10.2514/3.12149.
[44] P. R. Spalart, S. Deck, M. L. Shur, K. D. Squires, M. K. Strelets, and A. K. Travin, “A new version of detached-eddy simulation, resistant to ambiguous grid densities,” Theoretical and Computational Fluid Dynamics, vol. 20, no. 3, pp. 181–195, 2006, doi: https://doi.org/10.1007/s00162-006-0015-0.
[45] P. R. Spalart, W. H. Jou, S. R. Allmaras, and M. Strelets, “Comments on thefeasibility of LES for wings, and on a hybrid RANS/LES approach,” in First AFOSR International Conference on DNS/LES, Louisiana Tech University, 1997.
[46] M. L. Shur, P. R. Spalart, M. K. Strelets, and A. K. Travin, “A hybrid RANS-LES approach with delayed-DES and wall-modelled LES capabilities,” International Journal of Heat and Fluid Flow, vol. 29, no. 6, pp. 1638–1649, 2008, doi: https://doi.org/10.1016/j.ijheatfluidflow.2008.07.001.
[47] M. A. Feero, P. Lavoie, and P. E. Sullivan, “Influence of cavity shape on synthetic jet performance,” Sensors and Actuator," A: Physical, vol. 223, pp. 1–10, 2015, doi: https://doi.org/10.2514/1.J053605.
[48] N.A.S.A., “Uncertainty and Error in CFD Simulations.” Feb. 10, 2021. [Online]. Available: https://www.grc.nasa.gov/www/wind/valid/tutorial/errors.html.
[49] J. C. R. Hunt, A. A. Wray, and P. Moin, “Eddies, stream, and convergence in turbulent flows,” in Center for Turbulence Research Proceedings of the Summer Program, Stanford University, CTR, 1988.
[50] J. Zhou, R. J. Adrian, S. Balachandar, and T. M. Kendall, “Mechanisms for generating coherent packets of hairpin vortices in channel flow,” Journal of Fluid Mechanics, vol. 387, pp. 353–396, 1999, doi: doi:10.1017/S002211209900467X.
[51] J. Jeong and F. Hussain, “On the identification of a vortex,” Journal of Fluid Mechanics, vol. 285, pp. 69–94, 1995, doi: https://doi.org/10.1017/S0022112095000462.
[52] P. Chakraborty, S. Balachandar, and R. J. Adrian, “On the relationships between local vortex identification schemes,” Journal of Fluid Mechanics, vol. 535, pp. 189–214, 2005, doi: doi:10.1017/S0022112005004726.
[53] R. J. Arms and F. H. R, “Localized‐Induction Concept on a Curved Vortex and Motion of an Elliptic Vortex Ring,” Physics of Fluids, vol. 8, no. 4, pp. 553–339, 1965, doi: https://doi.org/10.1063/1.1761268.
[54] Viets H. and Sforza P. M., “Dynamics of Bilaterally Symmetric Vortex Rings,” Physics of Fluids, vol. 15, no. 2, pp. 230-240, 1972, doi: https://doi.org/10.1063/1.1693899.
[55] M. Kim, H. Lee, and W. Hwang, “Experimental study on the flow interaction between two synthetic jets emanating from a dual round orifice,” Experimental Thermal and Fluid Science, vol. 126, p. 110400, 2021, doi: https://doi.org/10.1016/j.expthermflusci.2021.110400.
[56] Y. Liu, Z. Ji, H. Wang, Z. Yu, and F. Shan, “On the three-dimensional flow evolution of a submerged synthetic jet with two circular orifices,” Physics of Fluids, vol. 36, p. 015110, 2024, doi: https://doi.org/10.1063/5.0183536.
[57] B. L. Smith and A. Glezer, “The formation and evolution of synthetic jets,” Physics of Fluids, vol. 10, no. 9, pp. 2281–2297, 1998, doi: https://doi.org/10.1063/1.869828.
All items in Spectrum are protected by copyright, with all rights reserved. The use of items is governed by Spectrum's terms of access.
Repository Staff Only: item control page
Download Statistics
Download Statistics