Experimental and Image Processing Study on the Effect of the Cavitation Phenomenon in a Nozzle Injector on the Hydrodynamic Behavior of the Spray

Document Type : Research Article

Authors

Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran

Abstract

The hydrodynamic behavior of liquid spray is influenced by the geometry of the injector nozzle, which has a significant impact on the combustion process and quality of fuel atomization. In this survey, transparent and visible nozzles were fabricated from Plexiglas to facilitate experimental visualization of the nozzle interior and enhance the accuracy of liquid spray investigation. To achieve this, three types of nozzles with varying orifice coefficients were prepared. Results showed that at a certain pressure, for a divergent conical nozzle, the intensity of cavitation increases, and it’s very prone to cavitation. Conversely, the convergent conical nozzle suppresses cavitation. As the pressure of fluid injection rises within nozzles, cavitation bubbles persist until reaching the orifice's end, resulting in the super-cavitation phenomenon. Further, increasing injection pressure triggers the hydraulic flip phenomenon. The occurrence of the super-cavitation phenomenon causes uniform droplet distribution of the resulting spray. In other words, The pressure corresponding to the occurrence of the super-cavitation phenomenon has a better droplet breakup and distribution (divergent conical nozzle with an injection pressure of 3 MPa). At a certain injection pressure with decreasing k factor outlet volume flow rate of the nozzle decreases and the spray cone angle increases. Therefore, the desired macroscopic characteristic of the spray could be determined by specifying the k factor.

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References

[1] X. Li, H. Zhou, L. Su, Y. Chen, Z. Qiao, F. Liu, Combustion and emission characteristics of a lateral swirl combustion system for DI diesel engines under low excess air ratio conditions, Fuel, 184 (2016) 672-680.
[2] R. Payri, J.P. Viera, V. Gopalakrishnan, P.G. Szymkowicz, The effect of nozzle geometry over internal flow and spray formation for three different fuels, Fuel, 183 (2016) 20-33.
[3] L. Su, X. Li, Z. Zhang, F. Liu, Numerical analysis on the combustion and emission characteristics of forced swirl combustion system for DI diesel engines, Energy conversion and management, 86 (2014) 20-27.
[4] H. Mohammadi, P. Jabbarzadeh, M. Jabbarzadeh, M.T. Shrevani-Tabar, Numerical investigation on the hydrodynamics of the internal flow and spray behavior of diesel fuel in a conical nozzle orifice with the spiral rifling like guides, Fuel, 196 (2017) 419-430.
[5] C. Tang, Z. Feng, C. Zhan, Z. Huang, Experimental study on the effect of injector nozzle K factor on the spray characteristics in a constant volume chamber: Near nozzle spray initiation, the macroscopic and the droplet statistics, Fuel, 202 (2017) 583-594.
[6] Y. Sun, Z. Guan, K. Hooman, Cavitation in diesel fuel injector nozzles and its influence on atomization and spray, Chemical engineering & technology, 42(1) (2019) 6-29.
[7] H. Hiroyasu, Spray breakup mechanism from the hole-type nozzle and its applications, Atomization and sprays, 10(3-5) (2000).
[8] Z. He, H. Zhou, L. Duan, M. Xu, Z. Chen, T. Cao, Effects of nozzle geometries and needle lift on steadier string cavitation and larger spray angle in common rail diesel injector, International Journal of Engine Research, 22(8) (2021) 2673-2688.
[9] B. Biçer, A. Sou, Application of the improved cavitation model to turbulent cavitating flow in fuel injector nozzle, Applied Mathematical Modelling, 40(7-8) (2016) 4712-4726.
[10] Z. He, Y. Chen, X. Leng, Q. Wang, G. Guo, Experimental visualization and LES investigations on cloud cavitation shedding in a rectangular nozzle orifice, International Communications in Heat and Mass Transfer, 76 (2016) 108-116.
[11] F. Salvador, M. Carreres, D. Jaramillo, J. Martínez-López, Comparison of microsac and VCO diesel injector nozzles in terms of internal nozzle flow characteristics, Energy conversion and management, 103 (2015) 284-299.
[12] Q. Li, C. Zong, F. Liu, T. Xue, A. Zhang, X. Song, Numerical and experimental analysis of the cavitation characteristics of orifice plates under high-pressure conditions based on a modified cavitation model, International Journal of Heat and Mass Transfer, 203 (2023) 123782.
[13] J. Cui, H. Lai, J. Li, Y. Ma, Visualization of internal flow and the effect of orifice geometry on the characteristics of spray and flow field in pressure-swirl atomizers, Applied Thermal Engineering, 127 (2017) 812-822.
[14] F.J. Salvador, J.J. López, J. De La Morena, M. Crialesi-Esposito, Experimental investigation of the effect of orifices inclination angle in multihole diesel injector nozzles. Part 1–Hydraulic performance, Fuel, 213 (2018) 207-214.
[15] R. Payri, F.J. Salvador, J. De La Morena, V. Pagano, Experimental investigation of the effect of orifices inclination angle in multihole diesel injector nozzles. Part 2–Spray characteristics, Fuel, 213 (2018) 215-221.
[16] J. Liu, Z. Liu, J. Wu, Z. Li, P. Chen, X. Gu, Visualization experiment and numerical calculation of the cavitation evolution inside the injector ball valve, Fuel, 329 (2022) 125500.
[17] Z.-Y. Sun, G.-X. Li, C. Chen, Y.-S. Yu, G.-X. Gao, Numerical investigation on effects of nozzle’s geometric parameters on the flow and the cavitation characteristics within injector’s nozzle for a high-pressure common-rail DI diesel engine, Energy Conversion and Management, 89 (2015) 843-861.
[18] Z. Feng, C. Zhan, C. Tang, K. Yang, Z. Huang, Experimental investigation on spray and atomization characteristics of diesel/gasoline/ethanol blends in high pressure common rail injection system, Energy, 112 (2016) 549-561.
[19] L. Guan, C. Tang, K. Yang, J. Mo, Z. Huang, Effect of di-n-butyl ether blending with soybean-biodiesel on spray and atomization characteristics in a common-rail fuel injection system, Fuel, 140 (2015) 116-125.
[20] Y. Dai, X. Zhang, G. Zhang, M. Cai, C. Zhou, Z. Ni, Numerical analysis of influence of cavitation characteristics in nozzle holes of curved diesel engines, Flow Measurement and Instrumentation, 85 (2022) 102172.
[21] M.T. Shervani-Tabar, S. Parsa, M. Ghorbani, Numerical study on the effect of the cavitation phenomenon on the characteristics of fuel spray, Mathematical and Computer Modelling, 56(5-6) (2012) 105-117.
[22] B. Jalili, P. Jalili, Numerical analysis of airflow turbulence intensity effect on liquid jet trajectory and breakup in two-phase cross flow, Alexandria Engineering Journal, 68 (2023) 577-585.
[23] A. Sou, S. Minami, R. Prasetya, R. Pratama, S. Moon, Y. Wada, H. Yokohata, X-ray visualization of cavitation in nozzles with various sizes, ICLASS-15,  (2015).
[24] Z. He, Z. Zhang, G. Guo, Q. Wang, X. Leng, S. Sun, Visual experiment of transient cavitating flow characteristics in the real-size diesel injector nozzle, International Communications in Heat and Mass Transfer, 78 (2016) 13-20.
[25] T. Hayashi, M. Suzuki, M. Ikemoto, Visualization of internal flow and spray formation with real size diesel nozzle, in:  12th triennial international conference on liquid atomization and spray systems, ICLASS, 2012, pp. 2-6.
[26] M. Ghiji, L. Goldsworthy, P.A. Brandner, V. Garaniya, P. Hield, Analysis of diesel spray dynamics using a compressible Eulerian/VOF/LES model and microscopic shadowgraphy, Fuel, 188 (2017) 352-366.
[27] Y. Wei, H. Zhang, L. Fan, B. Li, X. Leng, Z. He, Experimental study on influence of pressure fluctuation and cavitation characteristics of nozzle internal flow on near field spray, Fuel, 337 (2023) 126843.
[28] H. Ding, Z. Wang, Y. Li, H. Xu, C. Zuo, Initial dynamic development of fuel spray analyzed by ultra high speed imaging, Fuel, 169 (2016) 99-110.
[29] J.M. Desantes, R. Payri, F.J. Salvador, A. Gil, Development and validation of a theoretical model for diesel spray penetration, Fuel, 85(7-8) (2006) 910-917.
[30] A. Sou, S. Hosokawa, A. Tomiyama, Effects of cavitation in a nozzle on liquid jet atomization, International journal of heat and mass transfer, 50(17-18) (2007) 3575-3582.
AUT Journal of Mechanical Engineering
Volume 8, Issue 1
2024
Pages 67-82

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