阶梯型加速段对旋流喷嘴雾化特性的影响
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摘要
旋流内芯是压力旋流式喷嘴最主要的旋流发生构件,其几何特征直接影响压力旋流式喷嘴的喷雾特性.目前采用平滑型加速段的旋流内芯导流效率较低.为减小高流量条件下的能量损失,使喷嘴旋流内芯加速段对喷雾介质产生预旋效应,增强旋流强度,本文设计喷嘴旋流内芯加速段为阶梯型,其下段阶梯相对上段阶梯旋转15°,旋向与喷嘴旋流槽方向相同.利用粒子动态分析仪(particle dynamics analysis system,PDA)和高速摄影(charge coupled device,CCD)系统实验研究了加速段结构改进前后喷嘴的喷雾流量、雾场索特尔平均直径(Sauter mean diameter,SMD)、雾滴速度以及喷雾锥角,并分析了SMD、雾滴速度的轴向和径向分布特性.结果表明,背压差0.08~0.46 MPa范围内,阶梯型加速段对喷雾介质具有较好的预旋效果.喷嘴的流量提高了48.0%~51.8%;喷雾的轴向速度提升了31.4%~32.8%,径向速度提升了1.6%~16.8%;喷雾锥角减小了4.21°~6.57°;较高背压差下喷雾下游的SMD减小了9.8%.与平滑型加速段相比,阶梯型加速段的设计有效地提高了喷嘴的雾化质量.
Swirl atomizer inner core is the most important swirling component of the pressure swirling atomizer, the geometric topology of the swirl atomizer inner core directly affects the spray characteristics of pressure swirling atomizer. The current smooth acceleration section of the swirl atomizer inner core has lower flow efficiency. In order to reduce the energy loss, the swirl atomizer core accelerating section with ladder type has been designed to make spray medium pre-swirl and enhance the swirl strength in this paper, the lower part rotates 15° relative to the upper part, and the direction of the rotation is the same as the direction of the swirling slots of the atomizer. Spray flow rate, spray Sauter mean diameter(SMD), spray cone angle and droplet velocity were experimentally investigated by making use of particle dynamics analysis system(PDA) and charge coupled device experimental system(CCD) before and after the structure improvement of the acceleration section, and the axial and radial distributions of SMD and droplet velocity were also analyzed. Under the pressure ranges from 0.08 MPa to 0.46 MPa, the ladder type acceleration section has the better pre-swirl effect. The flow characteristics of the atomizer were increased by 48% to 51.8%; the axial and radial velocity of the spray were increased by 31.4% to 32.8% and 1.6% to 16.8%, respectively. The spray cone angle was reduced by 4.21° to 6.57°, and the SMD at downstream of the spray was decreased by 9.2% under higher pressure conditions. Compared with the smooth accelerating section, the application of ladder type accelerating section is beneficial to improve the quality of atomization.
Swirl atomizer inner core is the most important swirling component of the pressure swirling atomizer, the geometric topology of the swirl atomizer inner core directly affects the spray characteristics of pressure swirling atomizer. The current smooth acceleration section of the swirl atomizer inner core has lower flow efficiency. In order to reduce the energy loss, the swirl atomizer core accelerating section with ladder type has been designed to make spray medium pre-swirl and enhance the swirl strength in this paper, the lower part rotates 15° relative to the upper part, and the direction of the rotation is the same as the direction of the swirling slots of the atomizer. Spray flow rate, spray Sauter mean diameter(SMD), spray cone angle and droplet velocity were experimentally investigated by making use of particle dynamics analysis system(PDA) and charge coupled device experimental system(CCD) before and after the structure improvement of the acceleration section, and the axial and radial distributions of SMD and droplet velocity were also analyzed. Under the pressure ranges from 0.08 MPa to 0.46 MPa, the ladder type acceleration section has the better pre-swirl effect. The flow characteristics of the atomizer were increased by 48% to 51.8%; the axial and radial velocity of the spray were increased by 31.4% to 32.8% and 1.6% to 16.8%, respectively. The spray cone angle was reduced by 4.21° to 6.57°, and the SMD at downstream of the spray was decreased by 9.2% under higher pressure conditions. Compared with the smooth accelerating section, the application of ladder type accelerating section is beneficial to improve the quality of atomization.
引文
1甘晓华.航空燃气轮机燃油喷嘴技术(精).北京:国防工业出版社,2006(Gan Xiaohua.Aero-gas Turbine Fuel Injection Technology.Beijing:National Defense Industry Press,2006(in Chinese))
2 Zhao JB,Yang LJ.Simulation and experimental study on the atomization character of the pressure-swirl nozzle.Open Journal of Fluid Dynamics,2012,2(4):271-277
3 Press C.Gas turbine combustion.International Journal of Heat&Fluid Flow,1983,5(4):228
4 Rizk N.Fuel atomization effects on combustor performance//AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit,2013:393-411
5 Madsen J,Solberg T,Hjertager BH.Numerical simulation of internal flow in a large-scale pressure-swirl atomiser//19th International Conference on Liquid Atomization and Spray Systems,2004.
6 杨涛,张建,吕金明等.钝体射流火焰及其点火过程的大涡模拟.力学学报,2016,48(6):1281-1291(Yang Tao,Zhang Jian,LüJinming,et al.Large-eddy simulation of a bluff-body flame and the forced ignition process.Chinese Journal of Theoretical and Applied Mechanics,2016,48(6):1281-1291(in Chinese))
7 Cui J,Lai H,Li J,et al.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,2017,127:812-822
8 Maly M,Janackova L,Jedelsky J,et al.Influence of operating conditions and atomizer design on circumferential liquid distribution from small pressure-swirl atomizer[M].EPJ Web of Conferences,Dancova P,2017:143
9 陈晨,杨样,高宏力等.敞口式离心喷嘴内部及近喷口区域的流动特性.航空动力学报.2016(12):2988-2995(Chen Chen,Yang Yang,Gao Hongli,et al.Flow field in and near the open-end swirl injector.Journal of Aerospace Power,2016(12):2988-2995(in Chinese))
10 董兴涛,孙磊,卢德林等.低压旋流喷嘴喷雾特性数值仿真及结果分析.机电工程,2011,28(11):1306-1309(Dong Xingtao,Sun Lei,Lu Delin,et al.Numerical simulation and results analyzing on low-pressure swirl nozzle spray characteristics.Journal of Mechanical&Electrical Engineering,2011,28(11):1306-1309(in Chinese))
11 刘娟,李清廉,王振国等.基于VOF方法模拟离心式喷嘴内部流动过程.航空动力学报,2011,26(9):1986-1994(Liu Juan,Li Qinglian,Wang Zhenguo,et al.Numerical simulation of flow fieldin pressure-swirl injector based on VOF interface tracking method.Journal of Aerospace Power,2011,26(9):1986-1994(in Chinese))
12 刘娟,孙明波,李清廉等.基于VOF方法分析离心式喷嘴结构参数对性能的影响.航空动力学报,2011,26(12):2826-2833(Liu Juan,Sun Mingbo,Li Qinglian,et al.Analysis of geometric parameters influence on pressure swirl injector performance based on VOF interface tracking method.Journal of Aerospace Power,2011,26 (12):2826-2833(in Chinese))
13 刘国库,潘刚,郑洪涛.结构参数对喷嘴性能影响的数值研究.航空发动机,2015,41(5):28-32(Liu Guoku,Pan Gang,Zheng Hongtao.Numerical investigation for effect of structural parameters on nozzle preformance.Aeroengine,2015,41(5):28-32(in Chinese))
14 Sakman A,Jha S,Jog M,et al.A numerical parametric study of simplex fuel nozzle internal flow and performance.AIAA-98-4204,1998
15 Sun L,Huang Y,Liu Z.Improved semi-empirical prediction of viscous spraay cone angle for pressure swirl atomizers.Atomization And Sprays,2017,27(9):771-790
16 Rashad M,Huang Y,Zekun Z.Effect of geometric parameters on spray characteristics of pressure swirl atomizers.International Journal of Hydrogen Energy,2016,41(35):15790
17 Kim S,Khil T,Kim D,et al.Effect of geometric parameters on the liquid film thickness and air core formation in a swirl injector.Measurement Science and Technology,2010,20(1):187-188
18 Liu Z,Huang Y,Sun L.Studies on air core size in a simplex pressure-swirl atomizer.International Journal od Hydrogen Energy,2017,42(29SI):18649-18657
19 Xiao W,Huang Y.Improved semiempirical correlation to predict sauter mean diameter of pressure-swirl atomizers.Journal of Propulsion and Power,2014,30(6):1628-1635
20 Chen C,Yang Y,Yang S,et al.The spray characteristics of an openend swirl injector at ambient pressure.Aerospace Science and Technology,2017,67:78-87
21 韩亚威,王健,李海军.旋流式喷嘴喷雾效果的数值仿真研究.战术导弹技术,2013(4):54-58(Han YW,Wang J,Li HJ.Numerical investigation of the geometry characteristics effect on spray of swirl atomizer.Tactical Missile Technology,2013(4):54-58(in Chinese))
22 王国辉,蔡体敏,何国强等.一种旋流式喷嘴的实验和数值研究.推进技术,2003,24(1):28-32(Wang Guohui,Cai Timin,He Guoqiang,et al.Experimental and numerical investigation of a swirl atomizer.Journal of Propulsion Technology,2003,24(1):28-32(in Chinese))
23 潘华辰,周泽磊,刘雷.关键结构参数对离心式雾化喷嘴雾化效果的影响研究.机械工程学报,2017(2):199-206(Pan Huachen,Zhou Zelei,Liu Lei.Influence of design parameters of the swirl nozzle on its spray characteristics.Journal of Mechanical Engineering,2017(2):199-206(in Chinese))
24 王瑾,郝慧娣,曹乔乔.基于CFD的旋流喷嘴内部流场模拟研究.现代化工,2015,35(3):159-163(Wang Jin,Hao Huidi,Cao Qiaoqiao.Simulation of internal flow field in swirl nozzle by CFD.Modern Chemical Industry,2015,35(3):159-163(in Chinese))
25 闫云飞,张力,高振宇.低压旋流雾化喷嘴内液固两相流动的数值模拟.中国电机工程学报,2009,29(26):63-67(Yan Yunfei,Zhang Li,Gao Zhenyu.Numerical study on liquid-solid two-phase flow in low pressure swirl atomizing nozzle.Proceedings of the CSEE,2009,29(26):63-67(in Chinese))
26 欧长劲,李燕,苏之晓等.低压旋流喷嘴流场特性的数值仿真分析.轻工机械,2012,30(4):12-17(Ou Changjin,Li Yan,Su Zhixiao,et al.Numerical simulation analysis on flow field characteristics of low pressure swirl nozzle.Light Industry Machinery,2012,30(4):12 -17(in Chinese))
27 Durdina L,Jedelsky J,Jicha M.Investigation and comparison of spray characteristics of pressure-swirl atomizers for a small-sized aircraft turbine engine.International Journal of Heat and Mass Transfer,2014,78:892-900
28 李承觊,张德远.离心旋流式喷嘴雾化特性实验研究.装备环境工程.2016(6):47-51(Li Chengji,Zhang Deyuan.Research on atomizing properities of centrifugal swirl nozzle.Equipment Environmental Engineering,2016(6):47-51(in Chinese))
29 甘云华,江政纬,李海鸽.锥射流模式下乙醇静电喷雾液滴速度特性分析.力学学报,2017,49(6):1272-1279(Gan Yunhua,Jiang Zhengwei,Li Haige.A study on droplet velocity of ethanol during electro spraying process at cone-jet mode.Chinese Journal of Theoretical and Applied Mechanics,2017,49(6):1272-1279(in Chinese))
30 曹建明.液体喷雾学.北京:北京大学出版社,2013(Cao Jianming.Liquid Spray.Beijing:Peking University Press,2013(in Chinese))
31 Hamid AHA,Atan R.Spray characteristics of jet-swirl nozzles for thrust chamber injector.Aerospace Science&Technology,2009,13(4-5):192-196
32 Halder MR,Dash SK,Som SK.A numerical and experimental investigation on the coefficient of discharge and the spray cone angle of a solid cone swirl nozzle.Experimental Thermal and Fluid Science,2004,28(4):297-305
33 阎凯,宁智,吕明等.速度数量密度分布相关性研究.力学学报,2016,48(3):566-575(Yan Kai,Ning Zhi,L¨u Ming,et al.Study on correlation of breakup droplet size and velocity distribution of an annular swirling viscous liquid sheet.Chinese Journal of Theoretical and Applied Mechanics,2016,48(3):566-575(in Chinese))
2 Zhao JB,Yang LJ.Simulation and experimental study on the atomization character of the pressure-swirl nozzle.Open Journal of Fluid Dynamics,2012,2(4):271-277
3 Press C.Gas turbine combustion.International Journal of Heat&Fluid Flow,1983,5(4):228
4 Rizk N.Fuel atomization effects on combustor performance//AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit,2013:393-411
5 Madsen J,Solberg T,Hjertager BH.Numerical simulation of internal flow in a large-scale pressure-swirl atomiser//19th International Conference on Liquid Atomization and Spray Systems,2004.
6 杨涛,张建,吕金明等.钝体射流火焰及其点火过程的大涡模拟.力学学报,2016,48(6):1281-1291(Yang Tao,Zhang Jian,LüJinming,et al.Large-eddy simulation of a bluff-body flame and the forced ignition process.Chinese Journal of Theoretical and Applied Mechanics,2016,48(6):1281-1291(in Chinese))
7 Cui J,Lai H,Li J,et al.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,2017,127:812-822
8 Maly M,Janackova L,Jedelsky J,et al.Influence of operating conditions and atomizer design on circumferential liquid distribution from small pressure-swirl atomizer[M].EPJ Web of Conferences,Dancova P,2017:143
9 陈晨,杨样,高宏力等.敞口式离心喷嘴内部及近喷口区域的流动特性.航空动力学报.2016(12):2988-2995(Chen Chen,Yang Yang,Gao Hongli,et al.Flow field in and near the open-end swirl injector.Journal of Aerospace Power,2016(12):2988-2995(in Chinese))
10 董兴涛,孙磊,卢德林等.低压旋流喷嘴喷雾特性数值仿真及结果分析.机电工程,2011,28(11):1306-1309(Dong Xingtao,Sun Lei,Lu Delin,et al.Numerical simulation and results analyzing on low-pressure swirl nozzle spray characteristics.Journal of Mechanical&Electrical Engineering,2011,28(11):1306-1309(in Chinese))
11 刘娟,李清廉,王振国等.基于VOF方法模拟离心式喷嘴内部流动过程.航空动力学报,2011,26(9):1986-1994(Liu Juan,Li Qinglian,Wang Zhenguo,et al.Numerical simulation of flow fieldin pressure-swirl injector based on VOF interface tracking method.Journal of Aerospace Power,2011,26(9):1986-1994(in Chinese))
12 刘娟,孙明波,李清廉等.基于VOF方法分析离心式喷嘴结构参数对性能的影响.航空动力学报,2011,26(12):2826-2833(Liu Juan,Sun Mingbo,Li Qinglian,et al.Analysis of geometric parameters influence on pressure swirl injector performance based on VOF interface tracking method.Journal of Aerospace Power,2011,26 (12):2826-2833(in Chinese))
13 刘国库,潘刚,郑洪涛.结构参数对喷嘴性能影响的数值研究.航空发动机,2015,41(5):28-32(Liu Guoku,Pan Gang,Zheng Hongtao.Numerical investigation for effect of structural parameters on nozzle preformance.Aeroengine,2015,41(5):28-32(in Chinese))
14 Sakman A,Jha S,Jog M,et al.A numerical parametric study of simplex fuel nozzle internal flow and performance.AIAA-98-4204,1998
15 Sun L,Huang Y,Liu Z.Improved semi-empirical prediction of viscous spraay cone angle for pressure swirl atomizers.Atomization And Sprays,2017,27(9):771-790
16 Rashad M,Huang Y,Zekun Z.Effect of geometric parameters on spray characteristics of pressure swirl atomizers.International Journal of Hydrogen Energy,2016,41(35):15790
17 Kim S,Khil T,Kim D,et al.Effect of geometric parameters on the liquid film thickness and air core formation in a swirl injector.Measurement Science and Technology,2010,20(1):187-188
18 Liu Z,Huang Y,Sun L.Studies on air core size in a simplex pressure-swirl atomizer.International Journal od Hydrogen Energy,2017,42(29SI):18649-18657
19 Xiao W,Huang Y.Improved semiempirical correlation to predict sauter mean diameter of pressure-swirl atomizers.Journal of Propulsion and Power,2014,30(6):1628-1635
20 Chen C,Yang Y,Yang S,et al.The spray characteristics of an openend swirl injector at ambient pressure.Aerospace Science and Technology,2017,67:78-87
21 韩亚威,王健,李海军.旋流式喷嘴喷雾效果的数值仿真研究.战术导弹技术,2013(4):54-58(Han YW,Wang J,Li HJ.Numerical investigation of the geometry characteristics effect on spray of swirl atomizer.Tactical Missile Technology,2013(4):54-58(in Chinese))
22 王国辉,蔡体敏,何国强等.一种旋流式喷嘴的实验和数值研究.推进技术,2003,24(1):28-32(Wang Guohui,Cai Timin,He Guoqiang,et al.Experimental and numerical investigation of a swirl atomizer.Journal of Propulsion Technology,2003,24(1):28-32(in Chinese))
23 潘华辰,周泽磊,刘雷.关键结构参数对离心式雾化喷嘴雾化效果的影响研究.机械工程学报,2017(2):199-206(Pan Huachen,Zhou Zelei,Liu Lei.Influence of design parameters of the swirl nozzle on its spray characteristics.Journal of Mechanical Engineering,2017(2):199-206(in Chinese))
24 王瑾,郝慧娣,曹乔乔.基于CFD的旋流喷嘴内部流场模拟研究.现代化工,2015,35(3):159-163(Wang Jin,Hao Huidi,Cao Qiaoqiao.Simulation of internal flow field in swirl nozzle by CFD.Modern Chemical Industry,2015,35(3):159-163(in Chinese))
25 闫云飞,张力,高振宇.低压旋流雾化喷嘴内液固两相流动的数值模拟.中国电机工程学报,2009,29(26):63-67(Yan Yunfei,Zhang Li,Gao Zhenyu.Numerical study on liquid-solid two-phase flow in low pressure swirl atomizing nozzle.Proceedings of the CSEE,2009,29(26):63-67(in Chinese))
26 欧长劲,李燕,苏之晓等.低压旋流喷嘴流场特性的数值仿真分析.轻工机械,2012,30(4):12-17(Ou Changjin,Li Yan,Su Zhixiao,et al.Numerical simulation analysis on flow field characteristics of low pressure swirl nozzle.Light Industry Machinery,2012,30(4):12 -17(in Chinese))
27 Durdina L,Jedelsky J,Jicha M.Investigation and comparison of spray characteristics of pressure-swirl atomizers for a small-sized aircraft turbine engine.International Journal of Heat and Mass Transfer,2014,78:892-900
28 李承觊,张德远.离心旋流式喷嘴雾化特性实验研究.装备环境工程.2016(6):47-51(Li Chengji,Zhang Deyuan.Research on atomizing properities of centrifugal swirl nozzle.Equipment Environmental Engineering,2016(6):47-51(in Chinese))
29 甘云华,江政纬,李海鸽.锥射流模式下乙醇静电喷雾液滴速度特性分析.力学学报,2017,49(6):1272-1279(Gan Yunhua,Jiang Zhengwei,Li Haige.A study on droplet velocity of ethanol during electro spraying process at cone-jet mode.Chinese Journal of Theoretical and Applied Mechanics,2017,49(6):1272-1279(in Chinese))
30 曹建明.液体喷雾学.北京:北京大学出版社,2013(Cao Jianming.Liquid Spray.Beijing:Peking University Press,2013(in Chinese))
31 Hamid AHA,Atan R.Spray characteristics of jet-swirl nozzles for thrust chamber injector.Aerospace Science&Technology,2009,13(4-5):192-196
32 Halder MR,Dash SK,Som SK.A numerical and experimental investigation on the coefficient of discharge and the spray cone angle of a solid cone swirl nozzle.Experimental Thermal and Fluid Science,2004,28(4):297-305
33 阎凯,宁智,吕明等.速度数量密度分布相关性研究.力学学报,2016,48(3):566-575(Yan Kai,Ning Zhi,L¨u Ming,et al.Study on correlation of breakup droplet size and velocity distribution of an annular swirling viscous liquid sheet.Chinese Journal of Theoretical and Applied Mechanics,2016,48(3):566-575(in Chinese))