Damping Characteristics of Microfluid on Perforated Disks with a Centre Hole
-
摘要: 由缝隙流和挤压流动控制方程得到了滑流边界条件下的粘性修正的流动解.分析了圆盘的运动阻尼与缝隙大小、中心孔径以及圆盘厚度的关系,给出了设计滑膜和压膜合成阻尼的解析表达式.微流体对圆盘的阻尼与圆盘面的表面特性相关.通过修正动量协调系数可得到合适的等效粘度,以计算微流体对运动物体的阻尼力.算例表明,用本文中提出的解析方法得到的结果与有限元方法的数值解吻合.Abstract: Based on the equations of gap flow and squeezed flow,the viscous-modified solution under the slip boundary condition was obtained to calculate the damping characteristic of microfluid acting on a perforated disk with a centre hole.The correlation between the kinetic damping and dimensions of the perforated disk,such as the gap and the radius of the centre hole and the thickness of the disk,was obtained.An analytical expression of damping composed of slide film damping and squeeze film damping was presented.It was found that the damping of microfluid acting on the disk is correlative with surface characteristics of the disk.Suitable equivalent viscosity can be obtained by introducing a momentum accommodation coefficient to calculate the damping forces of microfluid acting on moving objects.A calculation example shows that the analytical solutions accord well with the numerical results obtained with finite element method.
-
MEHNER J,KURTH S,BILLEP D,et al.Simulation of gas damping in microstructures with nontrivial geometries[C] //Proc.of 11th Annual Int.Workshop on Micro Electro Mechanical Systems.Heidelberg,Germany,1998,Piscataway,NJ,USA:IEEE,1998:172-177.[2] BAO Minhang,YANG Heng,SUN Yuancheng,et al.Modified Reynolds' equation and analytical analysis of squeeze-film air damping of perforated structures[J].J.Micromech.Microeng,2003,13(6):795-800.[3] 张梓雄,董曾南.粘性流体力学[M].北京:清华大学出版社,1999:64.[4] 沈青著.稀薄气体动力学[M].北京:国防工业出版社,2003:185.[5] TIMO V J,HEIKKI K S.Equivalent-circuit model of the squeezed gas film in a silicon accelerometer[J].Sensors and Actuators,A Physical,1995,48(3):239-248.[6] WHITEJ W,RAADPE.Effect of a rough translating surface on gas film lubrication:a numerical and analytical study[J].Journal of Tribology,Trans.ASME,1987,109(4):271-275.[7] KOO J M,Clement K.Liquid flow in microchannels:experimental observations and computational analyses of microfluidics effects[J].J.Micromech Microeng,2003,13(5):568-579. -
点击查看大图
计量
- 文章访问数: 1234
- HTML全文浏览量: 64
- PDF下载量: 357
- 被引次数: 0
下载: