汽油机紧耦合式排气歧管振动特性研究
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摘要
汽车尾气净化是控制发动机排放的重要手段之一。为达到欧Ⅳ排放法规的要求,通常将催化转换器安装在发动机排气歧管的出口位置,也就是开发并使用了紧耦合式排气歧管。与传统布置方式相比,这种布置可以使催化剂快速起燃,充分发挥某些配方催化剂的效能,因而被执行欧Ⅳ排放标准的车辆广泛采用。
本文建立了紧耦合式排气歧管及排气系统的三维模型,运用有限元法及大型商用软件ANSYS对其振动问题进行了分析。首先,将紧耦合式排气歧管作为单独零件进行研究,分析其固有振动特性。针对排气歧管燃气加热作用比较明显的特点,运用间接法计算了热应力在排气歧管上的分布情况及其对排气歧管模态的影响。其次,以安装有紧耦合式排气歧管的排气系统作为研究对象分析整个排气系统的振动情况,得到整个排气系统的振型及在单位位移作用下的响应。本文还针对气流在排气系统上所激发的振动进行了特别研究,主要研究对象为紧耦合式排气歧管及排气系统中振动比较大的管段。最后,对排气系统振动分析中所发现的问题,通过重新设计悬挂点、调整隔振器刚度及安装动力吸振器等方法对其进行了优化设计。
The exhaust purification of the vehicle is one of the important measures to control engine exhaust discharging. In order to meet the requirements of Euro IV emission standard, the catalytic converter is installed at the exit of exchaust manifold usually, that means the tight coupled manifolds are developed and used. Compared with the traditional arrangement, this structure could make the catalyst combust rapidly and full use of the catalyst efficiency, which is used widely in the Euro IV emission standard vehicle.
This paper has established the three-dimensional models of tight coupled manifold and exhaust system, and the Finite Element Method and software ANSYS are employed to analyze their vibration problems. Firstly, the tight coupled manifold is investigated as a single part to analyze its natural vibration characteristics. In view of the characteristics of heated manifold by exhaust gas, the indirect method is used to calculate the thermal stress of exhaust manifold and the influence on the modes of the manifold. Secondly, the vibration situation of the whole exhaust system with the tight coupled manifold as the research object is analyzed, and the entire exchaust system vibration modes and the response are obtained under unit displacement. The vibration excited by exhaust gas is investigated also, which includes mainly the tight coupled manifold and the part of exhaust system with strong vibration. At last, regarding the problems discovered from vibration analysis of exhaust system, the optimum designs are conducted by redesigning the hanging of exchaust system, adjusting vibration isolator stiffness and installing dynamic vibration absorber.
本文建立了紧耦合式排气歧管及排气系统的三维模型,运用有限元法及大型商用软件ANSYS对其振动问题进行了分析。首先,将紧耦合式排气歧管作为单独零件进行研究,分析其固有振动特性。针对排气歧管燃气加热作用比较明显的特点,运用间接法计算了热应力在排气歧管上的分布情况及其对排气歧管模态的影响。其次,以安装有紧耦合式排气歧管的排气系统作为研究对象分析整个排气系统的振动情况,得到整个排气系统的振型及在单位位移作用下的响应。本文还针对气流在排气系统上所激发的振动进行了特别研究,主要研究对象为紧耦合式排气歧管及排气系统中振动比较大的管段。最后,对排气系统振动分析中所发现的问题,通过重新设计悬挂点、调整隔振器刚度及安装动力吸振器等方法对其进行了优化设计。
The exhaust purification of the vehicle is one of the important measures to control engine exhaust discharging. In order to meet the requirements of Euro IV emission standard, the catalytic converter is installed at the exit of exchaust manifold usually, that means the tight coupled manifolds are developed and used. Compared with the traditional arrangement, this structure could make the catalyst combust rapidly and full use of the catalyst efficiency, which is used widely in the Euro IV emission standard vehicle.
This paper has established the three-dimensional models of tight coupled manifold and exhaust system, and the Finite Element Method and software ANSYS are employed to analyze their vibration problems. Firstly, the tight coupled manifold is investigated as a single part to analyze its natural vibration characteristics. In view of the characteristics of heated manifold by exhaust gas, the indirect method is used to calculate the thermal stress of exhaust manifold and the influence on the modes of the manifold. Secondly, the vibration situation of the whole exhaust system with the tight coupled manifold as the research object is analyzed, and the entire exchaust system vibration modes and the response are obtained under unit displacement. The vibration excited by exhaust gas is investigated also, which includes mainly the tight coupled manifold and the part of exhaust system with strong vibration. At last, regarding the problems discovered from vibration analysis of exhaust system, the optimum designs are conducted by redesigning the hanging of exchaust system, adjusting vibration isolator stiffness and installing dynamic vibration absorber.
引文
[1]陶丽芳.汽车发动机排气系统性能分析研究.重庆大学硕士学位论文.2005:35-47页.
[2]K.R.Norman,A.Selamet,J.M.Novak.Perforated muffler manifold catalyst.Journal of Sound & Vibration,1998,218(4):711-734P.
[3]张逸,凌振国,龚镇.欧Ⅳ标准的催化转化器结构耐久性验证.汽车技术,2006,35(3):44-47页.
[4]张少华.采用新一代催化转化器是达到欧Ⅳ标准的重要途径.环保与安全,2005(18):34-36页.
[5]G.Konstandopoulos.Flow resistance descriptors for diesel particulate filters definitions,Measurements and Testing.Aerosol & Particle Technology Laboratory,9003(846):700-712P.
[6]庞剑,谌刚,何华.汽车噪声与振动.北京:北京理工大学出版社,2006:256-283页.
[7]穆丰瑞,海德利,董锡强.汽车排气歧管计算机辅助设计研究.内燃机学报,1995,13(4):401-407页.
[8]邢素芳,王现荣,王超,郭占敏.发动机排气系统振动分析.河北工业大学学报,2005,34(5):109-110页.
[9]张逸,凌振国,龚镇.欧Ⅳ标准的催化转化器进气端管设计.汽车工程,2006,28(11):997-1000页.
[10]ANSYS理论手册.1998:1-5页.
[11]张翠平.495G型汽油机进排气歧管的设计.农业机械学报,2000,31(5):82-84页.
[12]巴特,威尔逊.有限元分析中的数值方法.北京:科学出版社,1985:505-520页.
[13]Thomson,William.Theory of vibrations with aplication prentice hall,1971:53-110P.
[14]钱学森.流体力学的有限元分析.北京:水利电力出版社,1986:105-201页.
[15]ANSYS计算流体动力学分析指南.1998:25-49页.
[16]ANSYS分析指南.1998:1-18页.
[17]苏丽杰.流体管道振动问题研究.东北大学硕士学位论文.2001:14-36页.
[18]高耀东,郭喜平.ANSYS机械工程应用25例.北京:电子工业出版社,2007:217-235页.
[19]刘芹.弹体结构热振动特性分析.西北工业大学硕士学位论文.2004:22-40页.
[20]关振群,宋超,顾元宪等.有限元网格生成方法研究新进展.计算机辅助设计图形学学报,2003,15(1):1-14页.
[21]杨万里,许敏,刘国庆.杨俊伟发动机排气歧管热负荷数值模拟.华中科技大学学报,2006,12:98-100页.
[22]杨世铭,陶文铨.传热学.第三版.北京:高等教育出版社,1998:130-190页.
[23]赵金斗,邓兆祥,褚志刚,胡玉梅.排气歧管罩动态特性分析与结构改进设计.重庆大学学报(自然科学版),2005,9:19-22页.
[24]徐兀.汽车振动和噪声控制.北京:人民交通出版社,1987年:120-138页.
[25]杨卫农,戴关林.汽车排气系统噪音与振动的控制.轻型汽车技术,2007,7/8(215/216):34-36页.
[26]赵海澜,顾彦.汽车排气系统悬挂点优化.计算机辅助工程,2006(15增刊):230-231页.
[27]韩松涛,沈洵灏,罗清.娇车地板振动问题的研究.上海汽车,2003,11:32-35页.
[28]Thomas Repp.Fluid dynamic waterhammer simulations with consideration of structure interacton.ASME J.Fluids Engineering,1987,109:201-225P.
[29]Eun Bo Shim,Roger.D Kamm.Computational study of three dimensional fluid-structure.Department of Mechanical Engineering.Kumoh National University of Technology Kumi,Kyungbuk,Republic of Rorea,2002,204:114-120P.
[30]D.C.Wiggert,F.J.Hatfield.Analysis of liquid and structure transients in piping by the method of characteristics.ASME J.Fluids Engineering,1987,109:161-165P.
[31]G.C.Everstine.Dynamic analysis of fluid-filled piping systems using finite element techniques.J.Pressure Vessel Technology,1986,108(2):57-61P.
[32]马爱梅,陈红艳.基于流固耦合的弯管应力有限元分析.机械设计,2005,2(22增刊):277-278页.
[33]焦宗夏,华清,于凯.传输管道流固耦合振动的模态分析.航空学报,1999,20(4):316-320页.
[34]ANSYS耦合场分析指南.1998:31-39页.
[35]杜功焕,朱哲民,龚秀芬.声学基础.南京.南京大学出版社,2001:154-186页.
[36]潘文全.工程流体力学.北京:清华大学出版社,1988年:25-35页.
[37]李湘华,张小姣.柴油机排气歧管流场分析与结构优化.柴油机,2006,4(28):25-27页.
[38]初飞雪.两端简支输液管道流固耦合振动分析.中国机械工程,2006,17(3):248-251页.
[39]曹亮.输流管道流固耦合振动分析.昆明理工大学硕士学位论文.2004:14-49页.
[40]陈贵清,邢宝泉.管道结构的流固耦合振动研究.唐山学院学报,2004,17(3):91-92页.
[41]熊禾根,李公法.输流管道系统非线性流固耦合振动研究.长江大学学报,2006,3(2):91-92页.
[42]孙玉东,王锁泉,刘忠族,吴有生.液固耦合空间管路系统振动噪声的有限元分析方法.振动工程学报,2005,18(2):149-154页.
[43]D.C.Wiggert,M.W.Lesmez,F.J.Hatfield.Model analysis of vibrations in liquid-filled piping systems,fluid transients in fluid-structure interaction.ASME-EFD Vol.56:107-113P.
[44]徐芝纶.弹性力学.北京:人民教育出版社,1982:65-85页.
[45]吴永桥,鄢奉林.汽车排气总管的静力分析和模态分析.汽车工程,2000,22(3):10-13页.
[46]赵秀明,蔡璐.发动机排气歧管垫片开裂分析.汽车工艺与材料,2002(7):36-38页.
[2]K.R.Norman,A.Selamet,J.M.Novak.Perforated muffler manifold catalyst.Journal of Sound & Vibration,1998,218(4):711-734P.
[3]张逸,凌振国,龚镇.欧Ⅳ标准的催化转化器结构耐久性验证.汽车技术,2006,35(3):44-47页.
[4]张少华.采用新一代催化转化器是达到欧Ⅳ标准的重要途径.环保与安全,2005(18):34-36页.
[5]G.Konstandopoulos.Flow resistance descriptors for diesel particulate filters definitions,Measurements and Testing.Aerosol & Particle Technology Laboratory,9003(846):700-712P.
[6]庞剑,谌刚,何华.汽车噪声与振动.北京:北京理工大学出版社,2006:256-283页.
[7]穆丰瑞,海德利,董锡强.汽车排气歧管计算机辅助设计研究.内燃机学报,1995,13(4):401-407页.
[8]邢素芳,王现荣,王超,郭占敏.发动机排气系统振动分析.河北工业大学学报,2005,34(5):109-110页.
[9]张逸,凌振国,龚镇.欧Ⅳ标准的催化转化器进气端管设计.汽车工程,2006,28(11):997-1000页.
[10]ANSYS理论手册.1998:1-5页.
[11]张翠平.495G型汽油机进排气歧管的设计.农业机械学报,2000,31(5):82-84页.
[12]巴特,威尔逊.有限元分析中的数值方法.北京:科学出版社,1985:505-520页.
[13]Thomson,William.Theory of vibrations with aplication prentice hall,1971:53-110P.
[14]钱学森.流体力学的有限元分析.北京:水利电力出版社,1986:105-201页.
[15]ANSYS计算流体动力学分析指南.1998:25-49页.
[16]ANSYS分析指南.1998:1-18页.
[17]苏丽杰.流体管道振动问题研究.东北大学硕士学位论文.2001:14-36页.
[18]高耀东,郭喜平.ANSYS机械工程应用25例.北京:电子工业出版社,2007:217-235页.
[19]刘芹.弹体结构热振动特性分析.西北工业大学硕士学位论文.2004:22-40页.
[20]关振群,宋超,顾元宪等.有限元网格生成方法研究新进展.计算机辅助设计图形学学报,2003,15(1):1-14页.
[21]杨万里,许敏,刘国庆.杨俊伟发动机排气歧管热负荷数值模拟.华中科技大学学报,2006,12:98-100页.
[22]杨世铭,陶文铨.传热学.第三版.北京:高等教育出版社,1998:130-190页.
[23]赵金斗,邓兆祥,褚志刚,胡玉梅.排气歧管罩动态特性分析与结构改进设计.重庆大学学报(自然科学版),2005,9:19-22页.
[24]徐兀.汽车振动和噪声控制.北京:人民交通出版社,1987年:120-138页.
[25]杨卫农,戴关林.汽车排气系统噪音与振动的控制.轻型汽车技术,2007,7/8(215/216):34-36页.
[26]赵海澜,顾彦.汽车排气系统悬挂点优化.计算机辅助工程,2006(15增刊):230-231页.
[27]韩松涛,沈洵灏,罗清.娇车地板振动问题的研究.上海汽车,2003,11:32-35页.
[28]Thomas Repp.Fluid dynamic waterhammer simulations with consideration of structure interacton.ASME J.Fluids Engineering,1987,109:201-225P.
[29]Eun Bo Shim,Roger.D Kamm.Computational study of three dimensional fluid-structure.Department of Mechanical Engineering.Kumoh National University of Technology Kumi,Kyungbuk,Republic of Rorea,2002,204:114-120P.
[30]D.C.Wiggert,F.J.Hatfield.Analysis of liquid and structure transients in piping by the method of characteristics.ASME J.Fluids Engineering,1987,109:161-165P.
[31]G.C.Everstine.Dynamic analysis of fluid-filled piping systems using finite element techniques.J.Pressure Vessel Technology,1986,108(2):57-61P.
[32]马爱梅,陈红艳.基于流固耦合的弯管应力有限元分析.机械设计,2005,2(22增刊):277-278页.
[33]焦宗夏,华清,于凯.传输管道流固耦合振动的模态分析.航空学报,1999,20(4):316-320页.
[34]ANSYS耦合场分析指南.1998:31-39页.
[35]杜功焕,朱哲民,龚秀芬.声学基础.南京.南京大学出版社,2001:154-186页.
[36]潘文全.工程流体力学.北京:清华大学出版社,1988年:25-35页.
[37]李湘华,张小姣.柴油机排气歧管流场分析与结构优化.柴油机,2006,4(28):25-27页.
[38]初飞雪.两端简支输液管道流固耦合振动分析.中国机械工程,2006,17(3):248-251页.
[39]曹亮.输流管道流固耦合振动分析.昆明理工大学硕士学位论文.2004:14-49页.
[40]陈贵清,邢宝泉.管道结构的流固耦合振动研究.唐山学院学报,2004,17(3):91-92页.
[41]熊禾根,李公法.输流管道系统非线性流固耦合振动研究.长江大学学报,2006,3(2):91-92页.
[42]孙玉东,王锁泉,刘忠族,吴有生.液固耦合空间管路系统振动噪声的有限元分析方法.振动工程学报,2005,18(2):149-154页.
[43]D.C.Wiggert,M.W.Lesmez,F.J.Hatfield.Model analysis of vibrations in liquid-filled piping systems,fluid transients in fluid-structure interaction.ASME-EFD Vol.56:107-113P.
[44]徐芝纶.弹性力学.北京:人民教育出版社,1982:65-85页.
[45]吴永桥,鄢奉林.汽车排气总管的静力分析和模态分析.汽车工程,2000,22(3):10-13页.
[46]赵秀明,蔡璐.发动机排气歧管垫片开裂分析.汽车工艺与材料,2002(7):36-38页.