基于非结构网格流场的数值模拟及喷管型面优化
|
摘要
本文采用计算流体力学方法,重点研究了二维非结构网格的生成方法和基于非结构网格的定常/非定常N-S方程求解,并简单研究了矢量喷管的型面优化,用以提高矢量喷管气动性能。
本文首先研究了二维非结构网格的生成方法,采用Delaunay三角化与阵面推进相结合的方法。网格的划分及更新采用Delaunay三角化方法,网格内部节点的生成则是基于阵面推进法的思想。
本文还编写出了基于非结构网格的二维定常/非定常流场N-S方程计算程序。对于定常求解,本文采用格心格式的有限体积法对N-S方程作空间离散,湍流模型采用计算中广泛使用Badwin-Lomax紊流模型,它是一种代数模型,不增加求解方程的数目,计算量相对较小。用四步龙格—库塔方法作显式时间推进,同时采用当地时间步长、残值光顺等加速收敛措施。对于非定常求解,为了减少计算时间,本文采用隐式双时间法,伪时间域的求解用上面所讲的定常方法进行计算。本文给出的网格生成和流场计算的结果与实验数据符合较好。
本文还研究了优化方法,对矢量喷管的型面进行了优化设计。首先对基本矢量喷管型面进行网格生成,然后采用基于N-S方程的流场计算程序来求解流场,得到推力系数、阻力系数等气动参数、并以其中某个或某些参数构成目标函数,用复合形优化方法进行了优化设计。优化程序采用复合形法,它属于直接解法,是解有约束优化问题的有效方法之一,其应用十分广泛。其特点是原理简单、方法直观、不需要计算导数,也不需要一维搜索,复合形不要求为规则图形,灵活可变,适宜处理不等式约束问题。
另外,本文用计算流体力学方法对某型火箭发动机推力室氧腔流场进行了分析研究,确定了氧腔出口截面的总、静压力分布;提出了新的氧腔均流孔板的设计思想,并依此用流场分析结果设计了新的均流板;对新设计的均流板的氧腔进行了详细分析和实验验证。分析和验证表明新设计的均流板使氧腔出口截面压力畸变降低了11.5%,从而证明了本文提出的均流板设计思想和分析方法的正确性。
In this thesis a strategy applying the CFD for the generation of tetrahedral unstructured viscous grid on two-dimensional configurations has been introduced, and flow numerical simulation of steady or unsteady N-S equations under unstructured grids is researched in emphasis. In addition, a vector nozzle shape design method that couples viscous flow analysis, a complex method is described in this paper.The unstructured grids are generated by using the combination of Delaunay and advancing front techniques. Using the Dulaunay method, the grids is compartmentalized and updated. New inner nodes are created based on the concept of advancing front techniques.A computational program based on the 2-D unstructured grids is developed to solve the steady or unsteady N-S equation. The solution of steady flow employs a finite-volume method with the Badwin-Lomax turbulent model, an algebra model, which can' t add the number of the equations and easy to solve. The 4-step Rung-Kutta scheme is adopted and the techniques of artificial dissipation, local time stepping and residual smoothing are used to increase the convergence rate. With respect of the unsteady flow, implicit dual-time stepping method is employed to reduce the calculating time, and in preudo-time region, the method of solving steady flow, as presented above, is applied. Finally, examples of grid generation and flow calculation are presented. The numerical results are in well accord with the published data, which show that the numerical solution method is correct and robust.The optimum method is studied in this paper, a vector nozzle shape design method that couples viscous flow analysis; a complex method is described additionally. The optimum program is developed by using the complex optimum method, which is an effective method to solve the restraining problem, and widely used.
The optimum process is started by a base shape of vector nozzle. the unstructured grids of the vector nozzle is generated first and then the numerical flow is simulated by solving the N-S equations to gain the Aerodynamic parameters such as the coefficient of thrust force which is defined as design as the objective function, then the optimum program is executed by the Complex optimum method and the most aerodynamically favorable geometry that can be provide with the better aerodynamic performance is obtained.In this paper, the flow in the oxygen cavity of a rocket engine thrust chamber is investigated by using CFD methods, and the distribution of total and static pressure on exit of the oxygen cavity is determined. A new concept to design the orifice plate for flow uniformity in oxygen cavity is developed, and new orifice plates for flow uniformity are designed based on this concept and the results of flow characteristics. The detailed flow analysis and experiment validation is also performed, it shows that the newly designed orifice plate reduces 11.5% of pressure distortion on oxygen cavity exit, also shows that the concept and method provided in this paper are reasonable.
本文首先研究了二维非结构网格的生成方法,采用Delaunay三角化与阵面推进相结合的方法。网格的划分及更新采用Delaunay三角化方法,网格内部节点的生成则是基于阵面推进法的思想。
本文还编写出了基于非结构网格的二维定常/非定常流场N-S方程计算程序。对于定常求解,本文采用格心格式的有限体积法对N-S方程作空间离散,湍流模型采用计算中广泛使用Badwin-Lomax紊流模型,它是一种代数模型,不增加求解方程的数目,计算量相对较小。用四步龙格—库塔方法作显式时间推进,同时采用当地时间步长、残值光顺等加速收敛措施。对于非定常求解,为了减少计算时间,本文采用隐式双时间法,伪时间域的求解用上面所讲的定常方法进行计算。本文给出的网格生成和流场计算的结果与实验数据符合较好。
本文还研究了优化方法,对矢量喷管的型面进行了优化设计。首先对基本矢量喷管型面进行网格生成,然后采用基于N-S方程的流场计算程序来求解流场,得到推力系数、阻力系数等气动参数、并以其中某个或某些参数构成目标函数,用复合形优化方法进行了优化设计。优化程序采用复合形法,它属于直接解法,是解有约束优化问题的有效方法之一,其应用十分广泛。其特点是原理简单、方法直观、不需要计算导数,也不需要一维搜索,复合形不要求为规则图形,灵活可变,适宜处理不等式约束问题。
另外,本文用计算流体力学方法对某型火箭发动机推力室氧腔流场进行了分析研究,确定了氧腔出口截面的总、静压力分布;提出了新的氧腔均流孔板的设计思想,并依此用流场分析结果设计了新的均流板;对新设计的均流板的氧腔进行了详细分析和实验验证。分析和验证表明新设计的均流板使氧腔出口截面压力畸变降低了11.5%,从而证明了本文提出的均流板设计思想和分析方法的正确性。
In this thesis a strategy applying the CFD for the generation of tetrahedral unstructured viscous grid on two-dimensional configurations has been introduced, and flow numerical simulation of steady or unsteady N-S equations under unstructured grids is researched in emphasis. In addition, a vector nozzle shape design method that couples viscous flow analysis, a complex method is described in this paper.The unstructured grids are generated by using the combination of Delaunay and advancing front techniques. Using the Dulaunay method, the grids is compartmentalized and updated. New inner nodes are created based on the concept of advancing front techniques.A computational program based on the 2-D unstructured grids is developed to solve the steady or unsteady N-S equation. The solution of steady flow employs a finite-volume method with the Badwin-Lomax turbulent model, an algebra model, which can' t add the number of the equations and easy to solve. The 4-step Rung-Kutta scheme is adopted and the techniques of artificial dissipation, local time stepping and residual smoothing are used to increase the convergence rate. With respect of the unsteady flow, implicit dual-time stepping method is employed to reduce the calculating time, and in preudo-time region, the method of solving steady flow, as presented above, is applied. Finally, examples of grid generation and flow calculation are presented. The numerical results are in well accord with the published data, which show that the numerical solution method is correct and robust.The optimum method is studied in this paper, a vector nozzle shape design method that couples viscous flow analysis; a complex method is described additionally. The optimum program is developed by using the complex optimum method, which is an effective method to solve the restraining problem, and widely used.
The optimum process is started by a base shape of vector nozzle. the unstructured grids of the vector nozzle is generated first and then the numerical flow is simulated by solving the N-S equations to gain the Aerodynamic parameters such as the coefficient of thrust force which is defined as design as the objective function, then the optimum program is executed by the Complex optimum method and the most aerodynamically favorable geometry that can be provide with the better aerodynamic performance is obtained.In this paper, the flow in the oxygen cavity of a rocket engine thrust chamber is investigated by using CFD methods, and the distribution of total and static pressure on exit of the oxygen cavity is determined. A new concept to design the orifice plate for flow uniformity in oxygen cavity is developed, and new orifice plates for flow uniformity are designed based on this concept and the results of flow characteristics. The detailed flow analysis and experiment validation is also performed, it shows that the newly designed orifice plate reduces 11.5% of pressure distortion on oxygen cavity exit, also shows that the concept and method provided in this paper are reasonable.
引文
[1]、 朱自强等,《应用计算流体力学》,北京航空航天大学出版社,1988年8月.
[2]、 Kumar, A. , Hefner, J. N. Future Challenges and Opportunities inAerodynamics, The Aeronautical Journal, August 2000, 104:365 — 373.
[3]、 Launder, B.E. CFD for Aerodynamics Turbulent Flows: Progress and Problems, The Aeronautical Journal, August 2000,104:337 — 345.
[4]、 Neal T. Frink and Shahyar Z. Pirzadeh. Tetrahedral Finite-Volume Solutions to the Navier-Stokes Equations on Complex Configurations, NASA/TM-1998-208961
[5]、 Liu, C. Y. , Hwang, C. J. A New Strategy for Unstructured Mesh Generation, AIAA-2000-2249, Reno: AIAA 2000
[6]、 Luo, H. , Sharov, D. , Baum, J. D. and Lohner, R. , On the Computation of Compressible Turbulent Flows on Unstructured Grids, AIAA-2000-0926, Reno: AIAA 2000.
[7]、 Qunzhen Wang, Massey, S. J., Frink, N. T., Solving Navier-Stokes Equations with Advanced Turbulence Models on Three-Dimensional Unstructured Grids. AIAA-99-0156, Reno: AIAA 1999.
[8]、 Oki, Y. , Sakata, T. , Numerical Simulation of Transonic Flow past an F-16A Aircraft Configuration Using CASPER, AIAA-2000-0125, Reno: AIAA 2000.
[9]、 Peraire, J. , Morgan, K., Unstructured Mesh Generation for 3D Viscous Flow, AIAA-98-3010, Reno: AIAA 1998.
[10]、 Gatzke, T. D. , Weatherill, N. P., Unstructured Grid Generation Using Interactive Three-Dimensional Boundary and Efficient Three-Dimensional Volume Method, AIAA-93-3452, Reno: AIAA 1993.
[11]、 Golias, N. A. Tsiboukis, T. D., An Approach to Refining Three Dimensional Tetrahedral Meshes Based on Delaunay Transformations Int J Num Meth Eng, 1994,37: 793-812
[12]、 Pirzadeh, S., Recent Progress in Unstructured Grid Generation AIAA-92-0445, Reno: AIAA 1992
[13]、 Pirzadeh, S., Structured Background Grids for Generation of Unstructured Grids by Advancing Front Method, AIAA-91-3233, Reno: AIAA 1991
[14]、 Parikh, P. Prizadeh, S. and Lohner, R., A Package for 3D Unstructured Grid Generation Finite Element Flow Solution and Flow Field Visualization NASA CR-182090, 1990
[15]、 Frink, N. T., Assessment of an Unstructured-Grid Method for Predicting 3D Turbulent Viscous Flows AIAA-96-0292 Reno: 1996
[16]、 Jameson, A., SCHMIDT, W. And Turkel, E., Numerical Solution Of The Equations By Finite Volume Methods Using Runge-Kutta Time Stepping Schemes, AIAA Paper 81-159, 1981
[17]、 陈宝林,最优化理论与算法,北京:清华大学出版社,2000年3月
[18]、 王晓鹏,气动优化设计中的遗传算法研究,空气动力学学报,2001年6月,第二期,129—134
[19]、 张勇,李为吉等,基于多目标遗传算法的再入飞行器气动布局优化,空气动力学学报,2001年12月,第四期,478—282
[20]、 郑礼宝,全尺寸二元喷管红外辐射特性研究,航空学报,2002年3月,第二期,140—142
[21]、 杨弘炜,李椿萱,不同矢量偏角下二元喷管内流特性的数值研究,航空动力学报,1995年7月,第10卷,第三期,217—220
[22]、 Ann L Gaitonde, A Dual-time Method For The Solution Of The Unsteady Euler Equations Depart Of Aerospace Engineering university Of BRISTOL Bristol, United Kingdom
[23]、 陈国良等。遗传算法及其应用。北京:人民邮电出版社,1996年
[24]、 王子若,优化计算方法,机械工业出版社,1989年6月
[25]、 施光燕,董加礼,最优化算法,高等教育出版社,1999年9月
[26]、 谢祚水,结构优化设计概念,国防工业出版社,1997年5月
[27]、 D. F. Watson, Computing The N-Dimensional Delaunay Tessellation With Application To Voronoi Polytopes , The Computer J. , 24: 2(1981, 167-173)
[28]、 D. g. holmes, D. D. Snyder, The Generationof Unstructured Triangular Meshes Using Delaunay Triangulation, Proc. Int. conf On Numerical Grid Generation In Computational Fluid Dynamics.
[29]、 S. Rebay, Efficient Unstructured Mesh Generation By Means Of Delaunay Triangulation And Bowyer-Watson Algorithm, J. Comp. Phys, 106(1993), 125-138
[30]、 Bowyer, Computing Dirichlet Tessellation , The Computer j., 24: 2(1981), 162-166
[31]、 Mark Filipiak, Mesh Generation, Edinburgh Parallel Computing Centre, The University of Edinburgh, November 1996
[32]、 王刚,三维非结构粘性网格生成与N-S方程求解,西北工业大学硕士学位论文,2001年10月.
[33]、 Stolcis, L., Johnston, L. J., Solution of the Euler Equations onUnstructured Grids for Two-Dimensional Compressible Flow, TheAeronautical Journal, June/July 1990, 95: 181 195.
[34]、 Jameson, N., Schmidt, W. and Turkel, E., Numerical Solution of the Euler Equations by Finite Volume Methods Using Runge-Kutta Time Stepping Schemes, AIAA-81-1259 Reno: AIAA 1981
[35]、 封建湖,三维进气道系统流场的数值模拟研究,西北工业大学博士学位论文,1995年10月.
[36]、 刘战合,基于复合形法的翼形优化设计及并行计算研究,西北工业大学硕士学位论文,2004年3月.
[37]、 赵学瑞,廖其奠,粘性流体力学,北京,机械工业出版社,1984年
[38]、 阎庆绂,用速度线积分计算通风机入口前的涡量场,风机技术,,1997年10月第五期,16—18
[39]、 Frink, N. T., Parikh, P., Prizadeh, S., Aerodynamic Analysis of Complex Configurations using Unstructured Grids. AIAA-91-3292, Reno: AIAA1991.
[40]、 王新月,杨青真,《计算流体力学基础》,西北工业大学出版社
[41]、 黄长征、乔志德,跨音速流动的欧拉方程数值计算,中国航空科技文献,HJL-910078
[42]、 赵书军,三维叶轮机非定常颤震的研究,西北工业大学硕士学位论文,2003年10月
[43]、 邹正平,徐力平,双重时间步方法在非定常流场模拟中的应用,航空学报,2000年7月,第四期
[44]、 L. Kania, An Adaptive Grid Algorithm For Accurate Flow Field Calculations, AIAA—90—0321, 1990
[45]、 Chenoa Sago Yoon, Finite Element Analysis For High Speed Flows, 讲学稿件,1991年
[46]、 王新月,赵芝斌,刑宗文,二元矢量喷管流场及性能数值模拟,航空动力学报,1996年11月,第二期,199—201
[47]、 卢燕,樊思齐,轴对称推力矢量喷管的静态内部性能分析,飞机设计,2002年6月,第二期
[2]、 Kumar, A. , Hefner, J. N. Future Challenges and Opportunities inAerodynamics, The Aeronautical Journal, August 2000, 104:365 — 373.
[3]、 Launder, B.E. CFD for Aerodynamics Turbulent Flows: Progress and Problems, The Aeronautical Journal, August 2000,104:337 — 345.
[4]、 Neal T. Frink and Shahyar Z. Pirzadeh. Tetrahedral Finite-Volume Solutions to the Navier-Stokes Equations on Complex Configurations, NASA/TM-1998-208961
[5]、 Liu, C. Y. , Hwang, C. J. A New Strategy for Unstructured Mesh Generation, AIAA-2000-2249, Reno: AIAA 2000
[6]、 Luo, H. , Sharov, D. , Baum, J. D. and Lohner, R. , On the Computation of Compressible Turbulent Flows on Unstructured Grids, AIAA-2000-0926, Reno: AIAA 2000.
[7]、 Qunzhen Wang, Massey, S. J., Frink, N. T., Solving Navier-Stokes Equations with Advanced Turbulence Models on Three-Dimensional Unstructured Grids. AIAA-99-0156, Reno: AIAA 1999.
[8]、 Oki, Y. , Sakata, T. , Numerical Simulation of Transonic Flow past an F-16A Aircraft Configuration Using CASPER, AIAA-2000-0125, Reno: AIAA 2000.
[9]、 Peraire, J. , Morgan, K., Unstructured Mesh Generation for 3D Viscous Flow, AIAA-98-3010, Reno: AIAA 1998.
[10]、 Gatzke, T. D. , Weatherill, N. P., Unstructured Grid Generation Using Interactive Three-Dimensional Boundary and Efficient Three-Dimensional Volume Method, AIAA-93-3452, Reno: AIAA 1993.
[11]、 Golias, N. A. Tsiboukis, T. D., An Approach to Refining Three Dimensional Tetrahedral Meshes Based on Delaunay Transformations Int J Num Meth Eng, 1994,37: 793-812
[12]、 Pirzadeh, S., Recent Progress in Unstructured Grid Generation AIAA-92-0445, Reno: AIAA 1992
[13]、 Pirzadeh, S., Structured Background Grids for Generation of Unstructured Grids by Advancing Front Method, AIAA-91-3233, Reno: AIAA 1991
[14]、 Parikh, P. Prizadeh, S. and Lohner, R., A Package for 3D Unstructured Grid Generation Finite Element Flow Solution and Flow Field Visualization NASA CR-182090, 1990
[15]、 Frink, N. T., Assessment of an Unstructured-Grid Method for Predicting 3D Turbulent Viscous Flows AIAA-96-0292 Reno: 1996
[16]、 Jameson, A., SCHMIDT, W. And Turkel, E., Numerical Solution Of The Equations By Finite Volume Methods Using Runge-Kutta Time Stepping Schemes, AIAA Paper 81-159, 1981
[17]、 陈宝林,最优化理论与算法,北京:清华大学出版社,2000年3月
[18]、 王晓鹏,气动优化设计中的遗传算法研究,空气动力学学报,2001年6月,第二期,129—134
[19]、 张勇,李为吉等,基于多目标遗传算法的再入飞行器气动布局优化,空气动力学学报,2001年12月,第四期,478—282
[20]、 郑礼宝,全尺寸二元喷管红外辐射特性研究,航空学报,2002年3月,第二期,140—142
[21]、 杨弘炜,李椿萱,不同矢量偏角下二元喷管内流特性的数值研究,航空动力学报,1995年7月,第10卷,第三期,217—220
[22]、 Ann L Gaitonde, A Dual-time Method For The Solution Of The Unsteady Euler Equations Depart Of Aerospace Engineering university Of BRISTOL Bristol, United Kingdom
[23]、 陈国良等。遗传算法及其应用。北京:人民邮电出版社,1996年
[24]、 王子若,优化计算方法,机械工业出版社,1989年6月
[25]、 施光燕,董加礼,最优化算法,高等教育出版社,1999年9月
[26]、 谢祚水,结构优化设计概念,国防工业出版社,1997年5月
[27]、 D. F. Watson, Computing The N-Dimensional Delaunay Tessellation With Application To Voronoi Polytopes , The Computer J. , 24: 2(1981, 167-173)
[28]、 D. g. holmes, D. D. Snyder, The Generationof Unstructured Triangular Meshes Using Delaunay Triangulation, Proc. Int. conf On Numerical Grid Generation In Computational Fluid Dynamics.
[29]、 S. Rebay, Efficient Unstructured Mesh Generation By Means Of Delaunay Triangulation And Bowyer-Watson Algorithm, J. Comp. Phys, 106(1993), 125-138
[30]、 Bowyer, Computing Dirichlet Tessellation , The Computer j., 24: 2(1981), 162-166
[31]、 Mark Filipiak, Mesh Generation, Edinburgh Parallel Computing Centre, The University of Edinburgh, November 1996
[32]、 王刚,三维非结构粘性网格生成与N-S方程求解,西北工业大学硕士学位论文,2001年10月.
[33]、 Stolcis, L., Johnston, L. J., Solution of the Euler Equations onUnstructured Grids for Two-Dimensional Compressible Flow, TheAeronautical Journal, June/July 1990, 95: 181 195.
[34]、 Jameson, N., Schmidt, W. and Turkel, E., Numerical Solution of the Euler Equations by Finite Volume Methods Using Runge-Kutta Time Stepping Schemes, AIAA-81-1259 Reno: AIAA 1981
[35]、 封建湖,三维进气道系统流场的数值模拟研究,西北工业大学博士学位论文,1995年10月.
[36]、 刘战合,基于复合形法的翼形优化设计及并行计算研究,西北工业大学硕士学位论文,2004年3月.
[37]、 赵学瑞,廖其奠,粘性流体力学,北京,机械工业出版社,1984年
[38]、 阎庆绂,用速度线积分计算通风机入口前的涡量场,风机技术,,1997年10月第五期,16—18
[39]、 Frink, N. T., Parikh, P., Prizadeh, S., Aerodynamic Analysis of Complex Configurations using Unstructured Grids. AIAA-91-3292, Reno: AIAA1991.
[40]、 王新月,杨青真,《计算流体力学基础》,西北工业大学出版社
[41]、 黄长征、乔志德,跨音速流动的欧拉方程数值计算,中国航空科技文献,HJL-910078
[42]、 赵书军,三维叶轮机非定常颤震的研究,西北工业大学硕士学位论文,2003年10月
[43]、 邹正平,徐力平,双重时间步方法在非定常流场模拟中的应用,航空学报,2000年7月,第四期
[44]、 L. Kania, An Adaptive Grid Algorithm For Accurate Flow Field Calculations, AIAA—90—0321, 1990
[45]、 Chenoa Sago Yoon, Finite Element Analysis For High Speed Flows, 讲学稿件,1991年
[46]、 王新月,赵芝斌,刑宗文,二元矢量喷管流场及性能数值模拟,航空动力学报,1996年11月,第二期,199—201
[47]、 卢燕,樊思齐,轴对称推力矢量喷管的静态内部性能分析,飞机设计,2002年6月,第二期