讲座人:C W Lim教授
讲座时间:2014年7月3日下午3：00
讲座地点:address
讲座内容:题目：Thermo-acoustic theory and simulations for suspended carbon nanotube thin Film 报告内容: The research work develops an engineering model with analytical solutions and computational methods for the study of thermal-acoustic wave generated by a suspended carbon nanotube- (CNT) thin film. The system was developed by building a coupled thermal-mechanical model and the thermally induced acoustic response was solved. The governing equation was derived in a general sense to ensure that the solutions and responses are valid for both the near- and far-fields. Subsequently, a brief and concise analytical approximate solution for the acoustic pressure field within a specific frequency range was derived. To verify the model, formulation and solutions, some numerical examples using CNT-thin film in different surrounding gaseous media have been presented and compared with experimental measurement. Excellent agreement between numerical solutions and experiment is reported. One main significant conclusion drawn in this analysis is that the heat capacity per unit area significantly influences the acoustic pressure response and one that has a small heat capacity per unit area greatly improves the acoustic pressure performance. Furthermore, it is also concluded that a plane wave is generated in a near-field while it gradually transforms into a spherical wave in a far-field. Further simulation of the far-field directivity of the thermo-acoustic source shows that that the sound radiation area focuses in the vicinity of the thin film central-axis and high energy conversion efficiency could be obtained with respect to the mechanically driven acoustic transducers. 报告人简介：Prof Lim received a first degree from Univ. of Technology of Malaysia, a Master’s Degree and PhD from National University of Singapore and Nanyang Technological Univ., respectively. Prior to joining CityU, he was a post-doctoral research fellow at Department of Civil Engineering, The University of Queensland and Department of Mechanical Engineering, The University of Hong Kong. Prof. Lim is also a visiting professor at various universities including the University of Western Sydney, Dalian University of Technology, etc. He has expertise in vibration of plate and shell structures, dynamics of smart piezoelectric structures, nanomechanics and symplectic elasticity. He is the Associate Editor (Asia-Pacific Region) for Journal of Vibration Engineering & Technologies (SCI-listed journal), Guest Associate Editor for International Journal of Bifurcation and Chaos, and also on the editorial board of a few other international journals. He has published one of the best-selling titles in Engineering Mechanics entitled “Symplectic Elasticity” and co-authored with W.A. Yao and W.X. Zhong, as recorded in April 2010 by the publisher, World Scientific. He has published more than 200 international journal papers, accumulated more than 2000 independent citations, and one of the papers was granted the IJSS 2004-2008 most cited article award.
讲座时间:2014年7月3日下午3：00
讲座地点:address
讲座内容:题目：Thermo-acoustic theory and simulations for suspended carbon nanotube thin Film 报告内容: The research work develops an engineering model with analytical solutions and computational methods for the study of thermal-acoustic wave generated by a suspended carbon nanotube- (CNT) thin film. The system was developed by building a coupled thermal-mechanical model and the thermally induced acoustic response was solved. The governing equation was derived in a general sense to ensure that the solutions and responses are valid for both the near- and far-fields. Subsequently, a brief and concise analytical approximate solution for the acoustic pressure field within a specific frequency range was derived. To verify the model, formulation and solutions, some numerical examples using CNT-thin film in different surrounding gaseous media have been presented and compared with experimental measurement. Excellent agreement between numerical solutions and experiment is reported. One main significant conclusion drawn in this analysis is that the heat capacity per unit area significantly influences the acoustic pressure response and one that has a small heat capacity per unit area greatly improves the acoustic pressure performance. Furthermore, it is also concluded that a plane wave is generated in a near-field while it gradually transforms into a spherical wave in a far-field. Further simulation of the far-field directivity of the thermo-acoustic source shows that that the sound radiation area focuses in the vicinity of the thin film central-axis and high energy conversion efficiency could be obtained with respect to the mechanically driven acoustic transducers. 报告人简介：Prof Lim received a first degree from Univ. of Technology of Malaysia, a Master’s Degree and PhD from National University of Singapore and Nanyang Technological Univ., respectively. Prior to joining CityU, he was a post-doctoral research fellow at Department of Civil Engineering, The University of Queensland and Department of Mechanical Engineering, The University of Hong Kong. Prof. Lim is also a visiting professor at various universities including the University of Western Sydney, Dalian University of Technology, etc. He has expertise in vibration of plate and shell structures, dynamics of smart piezoelectric structures, nanomechanics and symplectic elasticity. He is the Associate Editor (Asia-Pacific Region) for Journal of Vibration Engineering & Technologies (SCI-listed journal), Guest Associate Editor for International Journal of Bifurcation and Chaos, and also on the editorial board of a few other international journals. He has published one of the best-selling titles in Engineering Mechanics entitled “Symplectic Elasticity” and co-authored with W.A. Yao and W.X. Zhong, as recorded in April 2010 by the publisher, World Scientific. He has published more than 200 international journal papers, accumulated more than 2000 independent citations, and one of the papers was granted the IJSS 2004-2008 most cited article award.