Eccentric needle displacement effect on spray formation from a multi orifice diesel injector
Tóm tắt
As emission regulations becomes stringent, improving injection process in internal combustion (IC) engines, is one of the ways of enhancing combustion characteristics and reducing pollutants emissions. Hence in this study, the effect of on-axis and off-axis internal needle displacement on injection characteristics from a multi orifice injector, used in direct injection IC engines, were investigated and analyzed. Two stage off-axis needle movement was formulated for the investigation. The first stage was at the initial stage of the needle lift, where the needle continuously glides along the internal cone of the nozzle body, before it completely departs the body. The second stage was considered to be from the moment the needle completely departed the nozzle body. Two different direction of the two stage off-axis needle displacement, were analyzed and their effect on flow and spray characteristics compared to those from on-axis needle displacement. The results showed that, off-axis needle displacements in the immediate areas of the nozzle orifices, causes exponential increment in spray jet penetrations as compared to off-axis needle displacement around the maximum needle lift position. Also, the displacement at the early stages of injection, had more influence on the spreading angles of spray jets from the nozzle orifices than the needle displacement around full needle lift.
Tài liệu tham khảo
Bae C, Kang J (2000) Diesel spray development of VCO nozzles for high pressure direct-injection. In: SAE 2000 World Congress, March 6, 2000 - March 9, 2000. SAE International
Cheng X, Chen L, Yan F (2014) Study of the characteristic of diesel spray combustion and soot formation using laser-induced incandescence (LII). J Energy Inst 87:383–392. https://doi.org/10.1016/j.joei.2013.07.001
Xu M, Cui Y, Deng K (2016) One-dimensional model on liquid-phase fuel penetration in diesel sprays. J Energy Inst 89:138–149. https://doi.org/10.1016/j.joei.2015.01.002
Battistoni M, Xue Q, Som S, Pomraning E (2014) Effect of off-axis needle motion on internal nozzle and near exit flow in a multi-hole diesel injector. SAE Int J Fuels Lubr 7:167–182. https://doi.org/10.4271/2014-01-1426
Bermudez V, Payri R, Salvador FJ, Plazas AH (2005) Study of the influence of nozzle seat type on injection rate and spray behaviour. Proc Inst Mech Eng Part D-Journal Automob Eng 219:677–689. https://doi.org/10.1243/095440705X28303
Salvador FJ, Carreres M, Jaramillo D, Martinez-Lopez J (2015) Comparison of microsac and VCO diesel injector nozzles in terms of internal nozzle flow characteristics. Energy Convers Manag 103:284–299. https://doi.org/10.1016/j.enconman.2015.05.062
Kastengren AL, Tilocco FZ, Powell CF, Manin J, Pickett LM et al (2012) Engine combustion network (ECN): measurements of nozzle geometry and hydraulic behavior. At Sprays 22:1011–1052. https://doi.org/10.1615/AtomizSpr.2013006309
Powell CF, Kastengren AL, Liu Z, Fezzaa K (2011) The effects of diesel injector needle motion on spray structure. J Eng Gas Turbines Power 133. https://doi.org/10.1115/1.4001073
Salvador FJ, Martinez-Lopez J, Romero JV, Rosello MD (2014) Study of the influence of the needle eccentricity on the internal flow in diesel injector nozzles by computational fluid dynamics calculations. Int J Comput Math 91:24–31. https://doi.org/10.1080/00207160.2013.770483
Chiatti G, Chiavola O, Palazzoni M, Palmieri F (2015) Diesel spray modeling under off-Axis needle displacement. In: SAE 2015 World Congress and Exhibition, April 21, 2015 - April 23, 2015 2015–April, AVL; continental; et al.; FEV; Fiat Chrysler Autom. SAE International. https://doi.org/10.4271/2015-01-0922
Kastengren AL, Powell CF, Liu Z, Fezzaa K, Wang J (2009) High-speed x-ray imaging of diesel injector needle motion. In: 2009 ASME Internal Combustion Engine Division Spring Technical Conference, May 3, 2009 - May 6, 2009. American Society of Mechanical Engineers, pp 247–258
Ohnishi H, Yoshida T, Arifuku T, Kadota T (1995) Characteristics of fuel discharge in multihole VCO nozzle. Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions Japan Soc Mech Eng Part B 61:1554–1559
Wang C, Moro A, Xue F, Wu X, Luo F (2018) The influence of eccentric needle movement on internal flow and injection characteristics of a multi-hole diesel nozzle. Int J Heat Mass Transf 117. https://doi.org/10.1016/j.ijheatmasstransfer.2017.10.057
Luo F, Jiang S, Moro A, Luo T, Zhou L, Wu X (2017) The development of a data acquisition system for measuring the injection rate of a multihole diesel injector. Sensors Actuators A Phys 261. https://doi.org/10.1016/j.sna.2017.04.037
Greif D, Edelbauer W, Strucl J (2014) Numerical simulation study of cavitating nozzle flow and spray propagation with respect to liquid compressibility effects. In: SAE Technical Papers 1. SAE International. https://doi.org/10.4271/2014-01-1421
von Berg E, Edelbauer W, Alajbegovic A, Tatschl R, Volmajer M et al (2005) Coupled simulations of nozzle flow, primary fuel jet breakup, and spray formation. J Eng Gas Turbines Power-Transactions Asme 127:897–908. https://doi.org/10.1115/1.1914803
Taghavifar H, Shervani-Tabar MT, Abbasalizadeh M (2015) Numerical study of the effects of injector needle movement and the nozzle inclination angle on the internal fluid flow and spray structure of a group-hole nozzle layout. Appl Math Model 39:7718–7733. https://doi.org/10.1016/j.apm.2015.04.032
Grief D, Sampl P, Edelbauer W (2014) Cavitating injector flow simulations considering longitudinal and lateral needle displacement. Int J Automot Eng 5:85–90
Moro A, Zhou Q, Xue F, Luo F (2017) Comparative study of flow characteristics within asymmetric multi hole VCO and SAC nozzles. Energy Convers Manag 132:482–493. https://doi.org/10.1016/j.enconman.2016.11.048
Postrioti L, Mariani F, Battistoni M, Mariani A (2009) Experimental and numerical evaluation of diesel spray momentum flux. SAE Tech. Pap.
Watanabe H, Nishikori M, Hayashi T, Suzuki M, Kakehashi N, Ikemoto M (2015) Visualization analysis of relationship between vortex flow and cavitation behavior in diesel nozzle. Int J Engine Res 16:5–12. https://doi.org/10.1177/1468087414562459
Salvador FJ, Carreres M, Jaramillo D, Martinez-Lopez J (2015) Analysis of the combined effect of hydrogrinding process and inclination angle on hydraulic performance of diesel injection nozzles. Energy Convers Manag 105:1352–1365. https://doi.org/10.1016/j.enconman.2015.08.035