湍流射流中示踪粒子的跟随性数值模拟分析
|
摘要
为了探究聚苯乙烯颗粒在射流场中的跟踪效果,采用大涡模拟(LES)方法求解射流流场,并与实验结果进行对比,以验证流场模型.定义了密度与水相同的5种不同粒径的虚拟颗粒,采用离散相模型(DPM)计算其运动轨迹,将其响应时间的理论分析结果与数值模拟结果进行对比,验证了DPM模型的准确性.随后对粒径范围为1~400μm的11种不同粒径的聚苯乙烯颗粒在一定雷诺数射流流场中的跟随特性进行了模拟计算,并与初始时刻相同位置的质点运动轨迹进行对比分析.结果表明,流场的复杂变化对颗粒的跟随性有很大影响,这表现在即使颗粒粒径很小时,颗粒与流场的速度依然存在一定偏差.在所研究工况下,粒径小于200μm的聚苯乙烯颗粒与水的速度偏差大部分在20%以内.
In order to study the tracking effect of polystyrene particles in a jet,the method of large eddy simulation(LES)was adopted to simulate the jet flow field and the results were compared with the experimental data to verify the numerical model.A kind of virtual particles with different sizes and the same density as water was defined.Through the calculation based on the discrete phase model(DPM),the theoretical analysis on the responding time was adopted to compare with the results of numerical simulation to confirm the accuracy of DPM.The simulations were then performed for the flow tracking capability of the polystyrene particles with the size in the range from 1 um to 400 !m in the jet flow field with a certain Reynolds number.And the polystyrene particles trajectories were compared with the trajectory of a massless particle.The results show that the complex flow field has a great influence on the flow tracking capability of particles.That is to say that even the particle size is very small,a certain speed deviation between the particles and fluid still exists.Besides,the speed deviation between the fluid and polystyrene particles with the sizebelow 200 um is smaller than 20%.
In order to study the tracking effect of polystyrene particles in a jet,the method of large eddy simulation(LES)was adopted to simulate the jet flow field and the results were compared with the experimental data to verify the numerical model.A kind of virtual particles with different sizes and the same density as water was defined.Through the calculation based on the discrete phase model(DPM),the theoretical analysis on the responding time was adopted to compare with the results of numerical simulation to confirm the accuracy of DPM.The simulations were then performed for the flow tracking capability of the polystyrene particles with the size in the range from 1 um to 400 !m in the jet flow field with a certain Reynolds number.And the polystyrene particles trajectories were compared with the trajectory of a massless particle.The results show that the complex flow field has a great influence on the flow tracking capability of particles.That is to say that even the particle size is very small,a certain speed deviation between the particles and fluid still exists.Besides,the speed deviation between the fluid and polystyrene particles with the sizebelow 200 um is smaller than 20%.
引文
[1]崔尔杰,洪金森.流动显示技术及其在流体力学研究中的应用[J].空气动力学学报,1991,9(2):190-199.
[2]金光,焦晶晶,吴晅.典型流场测速技术应用研究进展[J].矿山机械,2015,43(12):10-15.
[3]PAFFEL M,WILLERT C E,KOMPENHANS J.Particle image velocimetry:a practical guide[M].Berlin:Springer-Verlag,1998.
[4]梁桂华,赵宇.内燃机燃烧室流场PIV测试中示踪粒子跟随性分析[J].大连理工大学学报,2004,44(5):662-665.
[5]刘洪,陈方,励孝杰,等.高速复杂流动PIV技术研究实践与挑战[J].实验流体力学,2016,30(1):28-42.
[6]HJELMFELT A T J R,MOCKROS L F.Motion of discrete particles in a turbulent fluid[J].Applied Scientific Research,1966,16(1):149-161.
[7]沈钧涛,陈十一.球形粒子在流体中的跟随性[J].空气动力学学报,1989,7(1):50-58.
[8]黄社华,魏庆鼎.激光测速粒子对复杂流动的响应研究——Ⅱ典型流场中粒子跟随性的数值分析[J].水科学进展,2003,14(1):28-35.
[9]李恩邦,李志平,李淳,等.湍流中示踪粒子跟随性的数值分析[J].仪器仪表学报,2009,30(2):225-231.
[10]王宜,顾伯勤,邵春雷.基于Lagrange算法的熔盐泵叶轮内稀疏颗粒的跟随性分析[J].南京工业大学学报(自然科学版),2016,38(1):50-55.
[11]张乐禄.示踪粒子跟随性在离心泵内流场PIV测试研究[J].中国高新技术企业,2015(29):18-19.
[12]张晶晶.基于单帧单曝光图像法的多相流速度场和粒度分布测量研究[D].上海:上海理工大学,2011.
[13]陈晶丽,李琛,蔡小舒,等.流动多参数场的单帧图像法测量方法研究[J].实验流体力学,2015,29(6):67-73.
[14]王汉青,王志勇,寇广孝.大涡模拟理论进展及其在工程中的应用[J].流体机械,2004,32(7):23-27.
[15]苏铭德,黄素逸.计算流体力学基础[M].北京:清华大学出版社,1997.
[16]ZANG Y,STREET R L,KOSEFF J R.A dynamic mixed subgrid-scale model and its application to turbulent recirculating flows[J].Physics of Fluids,A:Fluid Dynamics,1993,5(12):3186-3196.
[17]朱赠好,周骛,蔡小舒.射流卷吸微米级结构的图像可视化研究[J].工程热物理学报,2014,35(6):1123-1126.
[18]MORSI S A,ALEXANDERAJ.An investigation of particle trajectories in two-phase flow systems[J].Journal of Fluid Mechanics,1972,55(2):193-208.
[19]FAN Q L,ZHANG H Q,GUO Y C,et al.Studies on the effects of stokes number in a twophase round turbulent jet[J].Journal of Combustion Science and Technology,1999,5(4):435-440.
[20]李志平.激光粒子图像测量中示踪粒子特性及实验方法研究[D].天津:天津大学,2007.
[2]金光,焦晶晶,吴晅.典型流场测速技术应用研究进展[J].矿山机械,2015,43(12):10-15.
[3]PAFFEL M,WILLERT C E,KOMPENHANS J.Particle image velocimetry:a practical guide[M].Berlin:Springer-Verlag,1998.
[4]梁桂华,赵宇.内燃机燃烧室流场PIV测试中示踪粒子跟随性分析[J].大连理工大学学报,2004,44(5):662-665.
[5]刘洪,陈方,励孝杰,等.高速复杂流动PIV技术研究实践与挑战[J].实验流体力学,2016,30(1):28-42.
[6]HJELMFELT A T J R,MOCKROS L F.Motion of discrete particles in a turbulent fluid[J].Applied Scientific Research,1966,16(1):149-161.
[7]沈钧涛,陈十一.球形粒子在流体中的跟随性[J].空气动力学学报,1989,7(1):50-58.
[8]黄社华,魏庆鼎.激光测速粒子对复杂流动的响应研究——Ⅱ典型流场中粒子跟随性的数值分析[J].水科学进展,2003,14(1):28-35.
[9]李恩邦,李志平,李淳,等.湍流中示踪粒子跟随性的数值分析[J].仪器仪表学报,2009,30(2):225-231.
[10]王宜,顾伯勤,邵春雷.基于Lagrange算法的熔盐泵叶轮内稀疏颗粒的跟随性分析[J].南京工业大学学报(自然科学版),2016,38(1):50-55.
[11]张乐禄.示踪粒子跟随性在离心泵内流场PIV测试研究[J].中国高新技术企业,2015(29):18-19.
[12]张晶晶.基于单帧单曝光图像法的多相流速度场和粒度分布测量研究[D].上海:上海理工大学,2011.
[13]陈晶丽,李琛,蔡小舒,等.流动多参数场的单帧图像法测量方法研究[J].实验流体力学,2015,29(6):67-73.
[14]王汉青,王志勇,寇广孝.大涡模拟理论进展及其在工程中的应用[J].流体机械,2004,32(7):23-27.
[15]苏铭德,黄素逸.计算流体力学基础[M].北京:清华大学出版社,1997.
[16]ZANG Y,STREET R L,KOSEFF J R.A dynamic mixed subgrid-scale model and its application to turbulent recirculating flows[J].Physics of Fluids,A:Fluid Dynamics,1993,5(12):3186-3196.
[17]朱赠好,周骛,蔡小舒.射流卷吸微米级结构的图像可视化研究[J].工程热物理学报,2014,35(6):1123-1126.
[18]MORSI S A,ALEXANDERAJ.An investigation of particle trajectories in two-phase flow systems[J].Journal of Fluid Mechanics,1972,55(2):193-208.
[19]FAN Q L,ZHANG H Q,GUO Y C,et al.Studies on the effects of stokes number in a twophase round turbulent jet[J].Journal of Combustion Science and Technology,1999,5(4):435-440.
[20]李志平.激光粒子图像测量中示踪粒子特性及实验方法研究[D].天津:天津大学,2007.