面向CFD的轿车底部参数化建模
|
摘要
CAD技术广泛用于汽车领域,带来了汽车设计、生产方式的新变革。本文以轿车底部模型为研究对象,阐述了其基于KBE的参数化、智能化设计CAD软件的开发过程及其关键技术。轿车底部简化设计模块是在集合最优的UG开发工具和设计方法的基础上,通过二次开发完成的。文中结合知识驱动自动化、知识熔接技术以及用户自定义特征等重要的研究内容,着重叙述了空气动力学CFD技术、参数化以及KBE技术的发展状况。作为基于UG平台而自主开发的车身部件参数化设计专用工具软件包,该软件模块通过设计向导用户界面的设计风格,从实际工业应用上已经完全实现了车身部件设计的自动化和智能化,从而为车身设计人员提供了专业的智能化设计工具。
In recent years, with the continued progress of science and technology, automobile manufacturers increasingly fierce competition among themselves facing users of product performance and the increasingly demanding high quality, safety and environmental standards and regulations more stringent constraints, and so the pressure, forcing its competition must shorten product development cycles, improve product quality, reduce development costs. Currently cars constantly speeding up the pace of upgrading, automotive products in the market gradually shortened life expectancy, and automotive research and development cycle has been reduced to 1 to 2 years, almost every year a new style, excellent quality, good performance and attractive looks, the car ride comfort type available. In the brutal competition in the market, further reducing vehicle development cycle and improving the quality of products has become the key to victory manufacturers. The vehicle aerodynamics as a vehicle development are closely related disciplines, it is necessary to seek its own breakthrough in the development of the automobile industry to increase the power. Reduce air resistance coefficient, improve its aerodynamic stability, control exhaust emissions, etc. can be embodied in the development of the automobile industry. How to better aerodynamics will be used in automotive product design and development. First of all, automobile aerodynamics should have achieved remarkable progress in the three-dimensional separation of cars and wake vortex resistance research.
This paper studies the content of automobile in the conceptualization of the development of the design phase. In the conceptual design stage it should complete vehicle design, including the exterior appearance, interior design and color design. Design requirements must achieve both functional and aesthetic. Beautiful external design to give people the enjoyment of the beauty at the same time also affect market sales, is an important work. But the exterior appearance and the design must take into account the car should be good aerodynamic characteristics, which requires the desinger to make aerodynamics analysis in the conceptual design stage. Under normal circumstances, the CAS model is not directly used for CFD analysis by CFD engineers. At this point models of the apparent need CFD engineers do a large number of model geometry clean-up and re-building work in the CAD / CAS software. When these are completed, the CFD engineer need to make a floor model, so closed body model. Because of the complex shape at the bottom of the car, to complete body of work on the model of closed is particularly difficult, but also very time-consuming. To address these issues, this paper model body at the bottom of the closed model has been simplified, and the creation of this simplified model is made to be a modular, integrated into the UG software.
Knowledge-based engineering (KBE) is an important branch of artificial intelligence and knowledge engineering theory in practice, and its essence is to "re-use." It focused on industrial products in its project development life cycle at every stage, is to make full use of all kinds of practical experience and expertise as well as other relevant information. The core of knowledge engineering is how to use the knowledge to solve the problem. The differences between knowledge-based systems and the traditional procedure is that the knowledge-based system handle knowledge as an object and the object of traditional processing is data.
In this paper, the first time, knowledge engineering and aerodynamics of combining theory and method applied to the concept of car design stage, and it research the methods of the knowledge-driven body structure design in the face of computational fluid dynamics (CFD), and study on the structure of car Design parameters, automation and knowledgeable, and development the bottom (chassis and wheel) parametric modeling efficient design tools. These tools can help the body engineers quickly and efficiently complete the body design, to shorten design time and improve design quality, and to enhance the competitiveness of enterprises in the automobile industry is of great significance.
At the bottom of the car in the conceptualization of appropriate design phase to simplify the development of this system is based on. But many parts of the car at the bottom are usually convex and concave grievances, so it uses zoning simplification. It can be divided into: nacelles, the Central Corridor and the exhaust pipe, spare cabin and four-wheel cover plate after suspension.
At the bottom of the engine compartment little effect on the flow of air, so it is simplified into a simple handling; The flat central channel and the exhaust pipe of a car are on the same floor location, and the two were in the process of simplifying a cuboids-shaped concave slot instead, the specific size under different development model in accordance with the requirements set; spare tire compartment is more complex, more prone to turbulence and eddy current, detailed its simplified compared to retain the basic module spare shape suspension after taking into account space, and it will spare module connected with the central channel processing, spare cabin on the various drawbar Thus, as shown in Figure 3.6; Four-wheel cover plate is the main consideration to increase the snow tires anti-skid chains enveloping face, body surface to simplify round hood line as baseline, with a tire width parameter values to the y / y-direction of a surface extrusion cover a round plate; the front and rear suspension are omitted, and the only reservation is the wheel; All of others at the bottom such as holes, small ribs are omitted.
Simplify the wheels in accordance with the results of previous studies of programmers. As the open area in the same circumstances, the appropriate number of openings will be increased to improve the aerodynamic characteristics. Generally speaking, as the number of openings increased, the total automobile aerodynamic resistance has decreased; with the increase in size of each hole the wheels of its own aerodynamic drag coefficient is increasing. Therefore wheel rims designed as a five-hole, the other dimensions are in accordance with the standard parameters calculated from the wheel.
This paper studies the second development process in the platform of UG NX5 by using UG/OPEN API language, using UG/UIStyler components function in accordance with the simplified model of the car at the bottom called for the establishment of an interactive interface, and the functional modeling is adopted use UG/OPEN API language and C, C + + integration achievable. The whole system is the development of commercial software development processes, and a high degree of practical value.
In this paper a three box car model as an example, the developed system is used to create the bottom CAD model which is a match with the automobile body model. Through its numerical simulation analysis, it access to several major aerodynamic parameters, and parameters of CFD analysis from the bottom of the plane simplified model to compare the data to prove that the simplified model created by the use of the system developed is more in the real value.
In recent years, with the continued progress of science and technology, automobile manufacturers increasingly fierce competition among themselves facing users of product performance and the increasingly demanding high quality, safety and environmental standards and regulations more stringent constraints, and so the pressure, forcing its competition must shorten product development cycles, improve product quality, reduce development costs. Currently cars constantly speeding up the pace of upgrading, automotive products in the market gradually shortened life expectancy, and automotive research and development cycle has been reduced to 1 to 2 years, almost every year a new style, excellent quality, good performance and attractive looks, the car ride comfort type available. In the brutal competition in the market, further reducing vehicle development cycle and improving the quality of products has become the key to victory manufacturers. The vehicle aerodynamics as a vehicle development are closely related disciplines, it is necessary to seek its own breakthrough in the development of the automobile industry to increase the power. Reduce air resistance coefficient, improve its aerodynamic stability, control exhaust emissions, etc. can be embodied in the development of the automobile industry. How to better aerodynamics will be used in automotive product design and development. First of all, automobile aerodynamics should have achieved remarkable progress in the three-dimensional separation of cars and wake vortex resistance research.
This paper studies the content of automobile in the conceptualization of the development of the design phase. In the conceptual design stage it should complete vehicle design, including the exterior appearance, interior design and color design. Design requirements must achieve both functional and aesthetic. Beautiful external design to give people the enjoyment of the beauty at the same time also affect market sales, is an important work. But the exterior appearance and the design must take into account the car should be good aerodynamic characteristics, which requires the desinger to make aerodynamics analysis in the conceptual design stage. Under normal circumstances, the CAS model is not directly used for CFD analysis by CFD engineers. At this point models of the apparent need CFD engineers do a large number of model geometry clean-up and re-building work in the CAD / CAS software. When these are completed, the CFD engineer need to make a floor model, so closed body model. Because of the complex shape at the bottom of the car, to complete body of work on the model of closed is particularly difficult, but also very time-consuming. To address these issues, this paper model body at the bottom of the closed model has been simplified, and the creation of this simplified model is made to be a modular, integrated into the UG software.
Knowledge-based engineering (KBE) is an important branch of artificial intelligence and knowledge engineering theory in practice, and its essence is to "re-use." It focused on industrial products in its project development life cycle at every stage, is to make full use of all kinds of practical experience and expertise as well as other relevant information. The core of knowledge engineering is how to use the knowledge to solve the problem. The differences between knowledge-based systems and the traditional procedure is that the knowledge-based system handle knowledge as an object and the object of traditional processing is data.
In this paper, the first time, knowledge engineering and aerodynamics of combining theory and method applied to the concept of car design stage, and it research the methods of the knowledge-driven body structure design in the face of computational fluid dynamics (CFD), and study on the structure of car Design parameters, automation and knowledgeable, and development the bottom (chassis and wheel) parametric modeling efficient design tools. These tools can help the body engineers quickly and efficiently complete the body design, to shorten design time and improve design quality, and to enhance the competitiveness of enterprises in the automobile industry is of great significance.
At the bottom of the car in the conceptualization of appropriate design phase to simplify the development of this system is based on. But many parts of the car at the bottom are usually convex and concave grievances, so it uses zoning simplification. It can be divided into: nacelles, the Central Corridor and the exhaust pipe, spare cabin and four-wheel cover plate after suspension.
At the bottom of the engine compartment little effect on the flow of air, so it is simplified into a simple handling; The flat central channel and the exhaust pipe of a car are on the same floor location, and the two were in the process of simplifying a cuboids-shaped concave slot instead, the specific size under different development model in accordance with the requirements set; spare tire compartment is more complex, more prone to turbulence and eddy current, detailed its simplified compared to retain the basic module spare shape suspension after taking into account space, and it will spare module connected with the central channel processing, spare cabin on the various drawbar Thus, as shown in Figure 3.6; Four-wheel cover plate is the main consideration to increase the snow tires anti-skid chains enveloping face, body surface to simplify round hood line as baseline, with a tire width parameter values to the y / y-direction of a surface extrusion cover a round plate; the front and rear suspension are omitted, and the only reservation is the wheel; All of others at the bottom such as holes, small ribs are omitted.
Simplify the wheels in accordance with the results of previous studies of programmers. As the open area in the same circumstances, the appropriate number of openings will be increased to improve the aerodynamic characteristics. Generally speaking, as the number of openings increased, the total automobile aerodynamic resistance has decreased; with the increase in size of each hole the wheels of its own aerodynamic drag coefficient is increasing. Therefore wheel rims designed as a five-hole, the other dimensions are in accordance with the standard parameters calculated from the wheel.
This paper studies the second development process in the platform of UG NX5 by using UG/OPEN API language, using UG/UIStyler components function in accordance with the simplified model of the car at the bottom called for the establishment of an interactive interface, and the functional modeling is adopted use UG/OPEN API language and C, C + + integration achievable. The whole system is the development of commercial software development processes, and a high degree of practical value.
In this paper a three box car model as an example, the developed system is used to create the bottom CAD model which is a match with the automobile body model. Through its numerical simulation analysis, it access to several major aerodynamic parameters, and parameters of CFD analysis from the bottom of the plane simplified model to compare the data to prove that the simplified model created by the use of the system developed is more in the real value.
引文
[1] 孙永伶. 轿车外流场的数值模拟. 同济大学硕士论文. 2001.1
[2] 黄天泽,黄金陵,汽车车身结构与设计,机械工业出版社,2004.07 P1-7
[3] 丁袆, 基于 KBE 及 DFM 的概念车身设计方法的研究及专用软件的开发. 吉林大学博士论文. 2004.12
[4] 胡平, 王成国, 庄茁. 虚拟工程与科学. 气象出版社. 2001.05
[5] 史野. 基于知识的臂式车门玻璃升降器的 CAD 软件开发. 吉林大学硕士论文. 2007
[6] 傅立敏. 降低国产轿车阻力的风洞试验研究. 空气动力学学报. 1998.6
[7] T.Breiting, E.Jehle, H.Reister,V.Schwarz, Development and Evaluation of a Numerical Simulation Strategy Designed to Support the Eary Stages of the Aerodynamic Development Process,SAE Technical Paper . 2002.01.0571, pp.3-4
[8] 杨博. 车轮旋转条件下轿车外流场的数值计算研究. 吉林大学硕士论文. 2004
[9] 丁袆, 尹伟, 胡平. 应用虚拟技术加快汽车开发进程. 吉林大学学报(工学版). 2002.7. 1671-5497(2002)03-0091-05
[10] E.Calkins N.Egging C. Scholz Gomez-Levi. A System Level KBE Tool for Vehicle Product Definition
[11] 李春梅. KBE 技术在 UG 中的应用. 中国模具论坛. 2004.6
[12] Becker B et al.Knowledge-Based Bumper Design System.AS-ME. 1997
[13] Liou S Y. Dissertion of Ohio State University. 1991
[14] Lomangino Pet al.Pedal: A Knowledge-Based Design Assistance for Automotive Pedal Packaging. ASME. 1998
[15] 李炭. 汽车内部布置 CAD 方法的研究与应用. 吉林工业大学硕士论文. 1997
[16] 裘真. 基于知识的轿车车身内部布置 CAD 系统的开发与应用初探. 吉林工业大学硕士论文. 1998
[17] 王仁广. 车身内部布置的微机 CAD 研究. 吉林工业大学硕士论文. 1998
[18] 龚礼洲. 基于知识的汽车车身总布置系统的研究和开发. 吉林工业大学博士论文. 2000
[19] 嵇建波. 轿车驾驶位置尺寸优化系统研究与开发. 吉林大学硕士论文. 2001
[20] 李国富. 基于 CATIA 的轿车驾驶员位置优化系统. 吉林大学硕士论文. 2002
[21] 龚梦泽. 基于 CATIA 的轿车仪表板布置设计方法研究. 吉林大学硕士论文. 2002
[22] 占建云. 汽车车身内部布置方法研究与总结. 吉林大学硕士论文. 2003
[23] 任金东. 车身布置方法研究和布置系统开发. 吉林大学博士学位论文. 2003
[24] 刘震. 基于 CATIA 的车门附件布置数据库的开发 吉林大学硕士学位论文. 2001
[25] 陈建涛. 基于 CATIA 平台的车门附件布置设计系统的开发. 吉林大学硕士学位论文. 2001
[26] 唐建春. 基于知识的车门附件布置设计系统的开发. 吉林大学硕士学位论文. 2002
[27] 李余兵. 车门附件布置知识库管理系统的研究与开发. 吉林大学硕士学位论文. 2003
[28] 程莉. 基于知识的车门附件布置设计系统的集成与应用. 吉林大学硕士学位论文. 2004
[29] 丁良旭, 徐宗俊, 郭钢. 基于知识工程的客车造型参数化设计研究.汽车技术. 2002 年第 11 期. P14～17
[30] 董正卫, 田立中, 付宣利. UG/OPEN API 编程基础. 清华大学出版社. 2002.8. P1-3
[31] 谷正气. 轿车车身. 人民交通出版社. 2002.10. P292-293
[32] Axon L, Garry K, Howell J. The influence of ground condition on the flow around a wheel located within a wheelhouse cavity[J]. SAE Technical Paper 1999-01-0806, 1999
[33] 傅立敏. 汽车空气动力学. 北京: 机械工业出版社. 1998.9. P42-43
[34] W.H.Hucho. Aerodynamics of Road Vehicles. Btterworth Co.Ltd. 1987
[35] 傅立敏. 汽车空气动力学数值计算. 北京: 北京理工大学出版社. 2001.1
[36] 孟汉新. 知识工程——科技创新的动力. 机械管理开发. 第 1 期. 2001.2. P22-23
[37] 于德江, 杜平安, 岳萍. 基于 KBE 的智能 CAD 方法研究. 机械设计与制造. 第 9期. 2007.9. P178
[38] Qijun Xia, Ming Rao. Dynamic case-based reasoning for process operation support system.Engineering application of artificial intelligence. 1999(12): 343-36
[39] 周雄辉, 彭颖红. 现代模具设计制造理论与技术. 上海: 上海交通大学出版社, 2000
[40] 刘波. 知识驱动的车身结构设计方法研究及软件系统关键技术开发. 吉林大学博士学位论文. 2007. P16
[41] 候清富, 郭岗. 软件工程实战基本功. 人民邮电出版社. 2005.01
[42] Alexis Scotto d’Apollonia, Benoit Granier, Pascal Debaty. Design of Experiments Methods Applied to CFD Simulations in Vehicle Aerodynamics. SAE. 2004-01-0443
[43] 傅立敏, 胡兴军, 张世村. 车轮辐板开孔对汽车外流场影响的数值模拟. 农业机械学报. 2006.1. P8-11
[44] 傅立敏, 胡兴军, 张世村. 不同几何参数车轮的汽车流场数值模拟研究. 汽车工程. 2006 年(第 28 卷)第 5 期. P452-459
[45] 傅立敏, 胡兴军, 张世村. CFD 仿真在汽车轮辋辐板设计中的应用研究. 汽车技术. 2006 年第 5 期. P16-19
[46] Axon L, Garry K, Howell J. An evaluation of CFD for modeling the flow around stationary and rotating wheels[J]. SAE Technical Paper 980032, 1998.
[47] Per Elofsson, Mark Bannister, Drag Reduction Mechanisms Due to Moving Ground and Wheel Rotation in Passenger Cars. SAE Technical Paper 2002-01-0531, pp.1-5
[48] Gerhard Wickern, Eckard Beese. Computational and Experimental Evaluation of a Pad Correction for a Wind Tunnel Balance Equipped for Rotating Wheels. SAE Technical Paper 2002-01-0532, pp.1-2
[49] 钱能. C++程序设计教程.清华大学出版社. 2003.06. P 451
[50] 谭浩张. C 程序设计(第二版).清华大学出版社.2003.1. P372
[51] 孔庆柱. 轿车外流场的数值模拟. 吉林大学硕士论文. 2003. P16-27
[2] 黄天泽,黄金陵,汽车车身结构与设计,机械工业出版社,2004.07 P1-7
[3] 丁袆, 基于 KBE 及 DFM 的概念车身设计方法的研究及专用软件的开发. 吉林大学博士论文. 2004.12
[4] 胡平, 王成国, 庄茁. 虚拟工程与科学. 气象出版社. 2001.05
[5] 史野. 基于知识的臂式车门玻璃升降器的 CAD 软件开发. 吉林大学硕士论文. 2007
[6] 傅立敏. 降低国产轿车阻力的风洞试验研究. 空气动力学学报. 1998.6
[7] T.Breiting, E.Jehle, H.Reister,V.Schwarz, Development and Evaluation of a Numerical Simulation Strategy Designed to Support the Eary Stages of the Aerodynamic Development Process,SAE Technical Paper . 2002.01.0571, pp.3-4
[8] 杨博. 车轮旋转条件下轿车外流场的数值计算研究. 吉林大学硕士论文. 2004
[9] 丁袆, 尹伟, 胡平. 应用虚拟技术加快汽车开发进程. 吉林大学学报(工学版). 2002.7. 1671-5497(2002)03-0091-05
[10] E.Calkins N.Egging C. Scholz Gomez-Levi. A System Level KBE Tool for Vehicle Product Definition
[11] 李春梅. KBE 技术在 UG 中的应用. 中国模具论坛. 2004.6
[12] Becker B et al.Knowledge-Based Bumper Design System.AS-ME. 1997
[13] Liou S Y. Dissertion of Ohio State University. 1991
[14] Lomangino Pet al.Pedal: A Knowledge-Based Design Assistance for Automotive Pedal Packaging. ASME. 1998
[15] 李炭. 汽车内部布置 CAD 方法的研究与应用. 吉林工业大学硕士论文. 1997
[16] 裘真. 基于知识的轿车车身内部布置 CAD 系统的开发与应用初探. 吉林工业大学硕士论文. 1998
[17] 王仁广. 车身内部布置的微机 CAD 研究. 吉林工业大学硕士论文. 1998
[18] 龚礼洲. 基于知识的汽车车身总布置系统的研究和开发. 吉林工业大学博士论文. 2000
[19] 嵇建波. 轿车驾驶位置尺寸优化系统研究与开发. 吉林大学硕士论文. 2001
[20] 李国富. 基于 CATIA 的轿车驾驶员位置优化系统. 吉林大学硕士论文. 2002
[21] 龚梦泽. 基于 CATIA 的轿车仪表板布置设计方法研究. 吉林大学硕士论文. 2002
[22] 占建云. 汽车车身内部布置方法研究与总结. 吉林大学硕士论文. 2003
[23] 任金东. 车身布置方法研究和布置系统开发. 吉林大学博士学位论文. 2003
[24] 刘震. 基于 CATIA 的车门附件布置数据库的开发 吉林大学硕士学位论文. 2001
[25] 陈建涛. 基于 CATIA 平台的车门附件布置设计系统的开发. 吉林大学硕士学位论文. 2001
[26] 唐建春. 基于知识的车门附件布置设计系统的开发. 吉林大学硕士学位论文. 2002
[27] 李余兵. 车门附件布置知识库管理系统的研究与开发. 吉林大学硕士学位论文. 2003
[28] 程莉. 基于知识的车门附件布置设计系统的集成与应用. 吉林大学硕士学位论文. 2004
[29] 丁良旭, 徐宗俊, 郭钢. 基于知识工程的客车造型参数化设计研究.汽车技术. 2002 年第 11 期. P14～17
[30] 董正卫, 田立中, 付宣利. UG/OPEN API 编程基础. 清华大学出版社. 2002.8. P1-3
[31] 谷正气. 轿车车身. 人民交通出版社. 2002.10. P292-293
[32] Axon L, Garry K, Howell J. The influence of ground condition on the flow around a wheel located within a wheelhouse cavity[J]. SAE Technical Paper 1999-01-0806, 1999
[33] 傅立敏. 汽车空气动力学. 北京: 机械工业出版社. 1998.9. P42-43
[34] W.H.Hucho. Aerodynamics of Road Vehicles. Btterworth Co.Ltd. 1987
[35] 傅立敏. 汽车空气动力学数值计算. 北京: 北京理工大学出版社. 2001.1
[36] 孟汉新. 知识工程——科技创新的动力. 机械管理开发. 第 1 期. 2001.2. P22-23
[37] 于德江, 杜平安, 岳萍. 基于 KBE 的智能 CAD 方法研究. 机械设计与制造. 第 9期. 2007.9. P178
[38] Qijun Xia, Ming Rao. Dynamic case-based reasoning for process operation support system.Engineering application of artificial intelligence. 1999(12): 343-36
[39] 周雄辉, 彭颖红. 现代模具设计制造理论与技术. 上海: 上海交通大学出版社, 2000
[40] 刘波. 知识驱动的车身结构设计方法研究及软件系统关键技术开发. 吉林大学博士学位论文. 2007. P16
[41] 候清富, 郭岗. 软件工程实战基本功. 人民邮电出版社. 2005.01
[42] Alexis Scotto d’Apollonia, Benoit Granier, Pascal Debaty. Design of Experiments Methods Applied to CFD Simulations in Vehicle Aerodynamics. SAE. 2004-01-0443
[43] 傅立敏, 胡兴军, 张世村. 车轮辐板开孔对汽车外流场影响的数值模拟. 农业机械学报. 2006.1. P8-11
[44] 傅立敏, 胡兴军, 张世村. 不同几何参数车轮的汽车流场数值模拟研究. 汽车工程. 2006 年(第 28 卷)第 5 期. P452-459
[45] 傅立敏, 胡兴军, 张世村. CFD 仿真在汽车轮辋辐板设计中的应用研究. 汽车技术. 2006 年第 5 期. P16-19
[46] Axon L, Garry K, Howell J. An evaluation of CFD for modeling the flow around stationary and rotating wheels[J]. SAE Technical Paper 980032, 1998.
[47] Per Elofsson, Mark Bannister, Drag Reduction Mechanisms Due to Moving Ground and Wheel Rotation in Passenger Cars. SAE Technical Paper 2002-01-0531, pp.1-5
[48] Gerhard Wickern, Eckard Beese. Computational and Experimental Evaluation of a Pad Correction for a Wind Tunnel Balance Equipped for Rotating Wheels. SAE Technical Paper 2002-01-0532, pp.1-2
[49] 钱能. C++程序设计教程.清华大学出版社. 2003.06. P 451
[50] 谭浩张. C 程序设计(第二版).清华大学出版社.2003.1. P372
[51] 孔庆柱. 轿车外流场的数值模拟. 吉林大学硕士论文. 2003. P16-27