### Abstract

The wave propagation approach is extended to the coupled frequency analysis of finite cylindrical pipes conveying dense fluid. The downstream, upstream and mixed frequencies of the pipe are defined and discussed. The effects of fluid and shell parameters on the coupled frequencies are investigated. The difference between the coupled and uncoupled frequencies decreases with the circumferential mode n, but increases with the mode n after the number n where the fundamental frequency is obtained. The fundamental frequency can change from one circumferential mode to another circumferential mode with the h/R ratios. However for a shorter shell the fundamental frequency may keep with the same mode n in the interested h/R ratios. For different boundary conditions the transition of fundamental frequency between circumferential modes occurs at different h/R ratios. The downstream frequency increases with increasing fluid velocity, whereas the upstream frequency decreases as the fluid velocity increases. However, the mixed frequency of the pipe decreases with the increase of the fluid velocity. For a given flow velocity all the three frequencies decrease with decreasing h/R ratios. However the mixed frequency drops more with increasing fluid velocity at small h/R ratios than at large h/R ratios. Therefore negative frequencies may occur for small h/R ratios if the fluid velocity is large enough, which means that instability occurs first for thinner pipes.

Original language | English (US) |
---|---|

Pages (from-to) | 287-295 |

Number of pages | 9 |

Journal | Computers and Structures |

Volume | 80 |

Issue number | 3-4 |

DOIs | |

State | Published - Feb 2002 |

### Fingerprint

### Keywords

- Coupled vibration
- Cylindrical pipes
- Fluid conveying
- Frequency analysis
- Parametric study
- Wave propagation

### ASJC Scopus subject areas

- Computer Science Applications
- Computational Mechanics

### Cite this

**Parametric studies of coupled vibration of cylindrical pipes conveying fluid with the wave propagation approach.** / Zhang, Xiaoming.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - Parametric studies of coupled vibration of cylindrical pipes conveying fluid with the wave propagation approach

AU - Zhang, Xiaoming

PY - 2002/2

Y1 - 2002/2

N2 - The wave propagation approach is extended to the coupled frequency analysis of finite cylindrical pipes conveying dense fluid. The downstream, upstream and mixed frequencies of the pipe are defined and discussed. The effects of fluid and shell parameters on the coupled frequencies are investigated. The difference between the coupled and uncoupled frequencies decreases with the circumferential mode n, but increases with the mode n after the number n where the fundamental frequency is obtained. The fundamental frequency can change from one circumferential mode to another circumferential mode with the h/R ratios. However for a shorter shell the fundamental frequency may keep with the same mode n in the interested h/R ratios. For different boundary conditions the transition of fundamental frequency between circumferential modes occurs at different h/R ratios. The downstream frequency increases with increasing fluid velocity, whereas the upstream frequency decreases as the fluid velocity increases. However, the mixed frequency of the pipe decreases with the increase of the fluid velocity. For a given flow velocity all the three frequencies decrease with decreasing h/R ratios. However the mixed frequency drops more with increasing fluid velocity at small h/R ratios than at large h/R ratios. Therefore negative frequencies may occur for small h/R ratios if the fluid velocity is large enough, which means that instability occurs first for thinner pipes.

AB - The wave propagation approach is extended to the coupled frequency analysis of finite cylindrical pipes conveying dense fluid. The downstream, upstream and mixed frequencies of the pipe are defined and discussed. The effects of fluid and shell parameters on the coupled frequencies are investigated. The difference between the coupled and uncoupled frequencies decreases with the circumferential mode n, but increases with the mode n after the number n where the fundamental frequency is obtained. The fundamental frequency can change from one circumferential mode to another circumferential mode with the h/R ratios. However for a shorter shell the fundamental frequency may keep with the same mode n in the interested h/R ratios. For different boundary conditions the transition of fundamental frequency between circumferential modes occurs at different h/R ratios. The downstream frequency increases with increasing fluid velocity, whereas the upstream frequency decreases as the fluid velocity increases. However, the mixed frequency of the pipe decreases with the increase of the fluid velocity. For a given flow velocity all the three frequencies decrease with decreasing h/R ratios. However the mixed frequency drops more with increasing fluid velocity at small h/R ratios than at large h/R ratios. Therefore negative frequencies may occur for small h/R ratios if the fluid velocity is large enough, which means that instability occurs first for thinner pipes.

KW - Coupled vibration

KW - Cylindrical pipes

KW - Fluid conveying

KW - Frequency analysis

KW - Parametric study

KW - Wave propagation

UR - http://www.scopus.com/inward/record.url?scp=0036465741&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036465741&partnerID=8YFLogxK

U2 - 10.1016/S0045-7949(02)00005-6

DO - 10.1016/S0045-7949(02)00005-6

M3 - Article

AN - SCOPUS:0036465741

VL - 80

SP - 287

EP - 295

JO - Computers and Structures

JF - Computers and Structures

SN - 0045-7949

IS - 3-4

ER -