LOCAL AND GLOBAL INSTABILITY OF FLUID-CONVEYING PIPES ON ELASTIC FOUNDATIONS |
| |
| Affiliation: | 1. School of Physics, University of the Witwatersrand, PO WITS 2050, South Africa;2. Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;1. Department of Physics, Shanghai Normal University, Shanghai 200234, China;2. MOE Key Laboratory of Advanced Micro-Structured Materials, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China;3. Department of Materials Science and Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China;1. Department of Aerospace Engineering, Texas A&M University, College Station, TX 77843, USA;2. Department of Civil Engineering, Sharif University of Technology, postal code: 111558639 Tehran, Islamic Republic of Iran;3. Department of Aerospace Engineering, Sharif University of Technology, postal code: 111558639 Tehran, Islamic Republic of Iran;4. Department of Aero-Space Engineering, Sharif University of Technology, postal code: 111558639 Tehran, Islamic Republic of Iran;1. Department of Cardiothoracic Surgery, St Vincent''s Hospital Melbourne, Fitzroy, Victoria, Australia;2. Department of Surgery, Austin Hospital, Heidelberg, Victoria, Australia;3. Department of Epidemiology and Preventative Medicine, Monash University, Prahran, Victoria, Australia;4. Department of Surgery (MMC), Monash University, Clayton, Victoria, Australia;5. Department of Cardiothoracic Surgery, Monash Medical Centre, Clayton, Victoria, Australia;6. Cabrini Medical Centre, Malvern, Victoria, Australia;7. University of Melbourne, Department of Surgery, St Vincent''s Hospital Melbourne, Fitzroy, Victoria, Australia |
| |
| Abstract: | We investigate the relationship between the local and global bending motions of fluid-conveying pipes on an elastic foundation. The local approach refers to an infinite pipe without taking into account its finite ends, while in the global approach we consider a pipe of finite length with a given set of boundary conditions. Several kinds of propagating disturbances are identified from the dispersion relation, namely evanescent, neutral and unstable waves. As the length of the pipe is increased, the global criterion for instability is found to coincide with local neutrality, whereby a local harmonic forcing only generates neutral waves. For sets of boundary conditions that give rise only to static instabilities, the criterion for global instability of the long pipe is that static neutral waves exist. Conversely, for sets of boundary conditions that allow dynamic instabilities, the criterion for global instability of the long pipe corresponds to that for the existence of neutral waves of finite nonzero frequency. These results are discussed in relation with the work of Kulikovskii and other similar approaches in hydrodynamic stability theory. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
