scholarly journals 443 Nonplanar Vibration of a Cantilevered Pipe due to an Internal Flow : The Effects of Horizontal Excitation at the Upper End

2003 ◽  
Vol 2003 (0) ◽  
pp. _443-1_-_443-6_
Author(s):  
Kiyotaka YAMASHITA ◽  
Jun AGATA ◽  
Masatsugu YOSHIZAWA
Keyword(s):  
Internal Flow ◽  
Nonplanar Vibration ◽  
Cantilevered Pipe

A Coupled Two-Way Fluid-Structure Interaction Analysis for the Dynamics of a Partially Confined Cantilevered Pipe Under Simultaneous Internal and External Axial Flow in Opposite Directions

2021 ◽  
Author(s):  
Farhang Daneshmand ◽  
Tahereh Liaghat ◽  
Michael Paidoussis
Keyword(s):  
Interaction Analysis ◽  
Velocity Ratio ◽  
Fluid Structure Interaction ◽  
Axial Flow ◽  
Internal Flow ◽  
Structural Domain ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Cantilevered Pipe ◽  
Central Pipe

Abstract This paper presents the results of a coupled two-way fluid-structure interaction analysis of a slender flexible vertical cantilevered pipe hanging concentrically within a shorter rigid tube forming an annulus. The pipe is subjected to internal and annular flows simultaneously. This system has applications in brine production and salt-cavern hydrocarbon storage. In the present study, the fluid-structure problem is solved with a finite-volume-based CFD code for the fluid domain coupled to a finite-element-based CSM code for the structural domain. The numerical results obtained for the free-end displacement of the central pipe versus the annular/internal flow velocity ratio U_o/U_i are presented and compared with those obtained from experiment. The capability of the numerical model to predict the onset of the experimentally observed flutter instability in the system is also examined. This provides a better insight into the dynamics of the system.

Internal flow effect on the cross-flow vortex-induced vibration of a cantilevered pipe discharging fluid

2017 ◽  
Vol 137 ◽  
pp. 120-128 ◽  
Author(s):  
Shuai Meng ◽  
Hiroyuki Kajiwara ◽  
Weijing Zhang
Keyword(s):  
Cross Flow ◽  
Internal Flow ◽  
Vortex Induced Vibration ◽  
Flow Effect ◽  
Cantilevered Pipe ◽  
The Cross ◽  
Flow Vortex

Dynamics of a Pipe Aspirating Fluid Such as Might be Used in Ocean Mining

1985 ◽  
Vol 107 (2) ◽  
pp. 250-255 ◽  
Author(s):  
M. P. Paidoussis ◽  
T. P. Luu
Keyword(s):  
Internal Flow ◽  
Large Mass ◽  
Wave Action ◽  
Mining System ◽  
Fluid Medium ◽  
Small Flow ◽  
Marine Currents ◽  
Cantilevered Pipe ◽  
Ocean Mining ◽  
Passive Stabilization

This paper presents an investigation into the dynamics and stability of a long, vertically disposed, cantilevered pipe, submerged in and aspirating fluid from the free lower end, and conveying it upwards to the supported upper end; the pipe has a large mass attached to its free end. The arrangement represents an idealization of an ocean mining system. This paper reports on the first phase of this work, in which the following simplifications have been made: (i) the pipe is straight at equilibrium; (ii) the effects of marine currents and wave action are not considered. It is shown that under the action of the internal flow, the system is inherently unstable, by flutter, and that it does not lose stability at vanishingly small flow velocities, only because of dissipation, through friction with the external fluid medium. Effective passive stabilization of the system may be achieved through artificial augmentation of this form of dissipation.

scholarly journals FREE VIBRATION INDUCED BY INTERNAL FLOW IN CANTILEVERED PIPE UNDER DIFFERENT PARAMETERS

2020 ◽  
Vol 5 (10) ◽  
Author(s):  
DAHMANE MOULOUDA ◽  
SAMIR ZAHAF,MAWHOUB SOUBIHC ◽  
BENKHETAB MOHAMEDD ◽  
DJILALI BOUTCHICHAE
Keyword(s):  
Free Vibration ◽  
Internal Flow ◽  
Cantilevered Pipe

Nonlinear Stability of a Fluid-Conveying Cantilevered Pipe With End Mass in Case of Horizontal Excitation at the Upper End

2010 ◽  
Author(s):  
Hiroaki Furuya ◽  
Kiyotaka Yamashita ◽  
Hiroshi Yabuno
Keyword(s):  
Limit Cycle ◽  
Excitation Frequency ◽  
Internal Flow ◽  
Frequency Component ◽  
Single Frequency ◽  
Dynamic Features ◽  
Cycle Frequency ◽  
Excited Vibration ◽  
Cantilevered Pipe ◽  
The Stability

Nonplanar vibrations of a cantilevered pipe with an end mass is studied. We have already clarified the nonplanar vibrations with a single frequency component when the pipe conveys fluid whose velocity is slightly over the critical value, above which the lateral vibration of the pipe is self-excited due to the internal flow. Moreover, for the case that the upper end of the pipe is excited periodically in the horizontal direction, we have shown in the previous paper that the nonplanar limit cycle motions start complex spatial transients and settle down to stationary planar forced-excited vibration when the excitation frequency is near the nonplanar limit cycle frequency. The purpose of this paper is to examine the stability of the nonplanar pipe vibrations when the nonplanar self-excited pipe vibrations are subjected to the excitation at the upper end. A set of ordinary differential equations, which govern the amplitudes and phases of unstable mode vibration and contain the effect of excitation at the upper end are derived. Stability analysis of these equations clarifies the nonlinear interactions between nonplanar self-excited pipe vibrations and the forced excitation. Second, the experiments are conducted with a silicon rubber pipe conveying water, confirming the dynamic features of pipe vibrations for the horizontal excitation.

Investigation of the natural ventilation of wind catchers with different geometries in arid region houses

2020 ◽  
Vol 14 (3) ◽  
pp. 7109-7124
Author(s):  
Nasreddine Sakhri ◽  
Younes Menni ◽  
Houari Ameur ◽  
Ali J. Chamkha ◽  
Noureddine Kaid ◽  
...  
Keyword(s):  
Arid Region ◽  
Natural Ventilation ◽  
Reduction Rate ◽  
Internal Flow ◽  
Climatic Conditions ◽  
Maximum Pressure ◽  
Ventilation Technique ◽  
Window Position ◽  
The One ◽  
Flow Velocities

The wind catcher or wind tower is a natural ventilation technique that has been employed in the Middle East region and still until nowadays. The present paper aims to study the effect of the one-sided position of a wind catcher device against the ventilated space or building geometry and its natural ventilation performance. Four models based on the traditional design of a one-sided wind catcher are studied and compared. The study is achieved under the climatic conditions of the South-west of Algeria (arid region). The obtained results showed that the front and Takhtabush’s models were able to create the maximum pressure difference (ΔP) between the windward and leeward of the tower-house system. Internal airflow velocities increased with the increase of wind speed in all studied models. For example, at Vwind = 2 m/s, the internal flow velocities were 1.7, 1.8, 1.3, and 2.5 m/s for model 1, 2, 3, and 4, respectively. However, at Vwind = 6 m/s, the internal flow velocities were 5.6, 5.5, 2.5, and 7 m/s for model 1, 2, 3, and 4, respectively. The higher internal airflow velocities are given by Takhtabush, traditional, front and middle tower models, respectively, with a reduction rate between the tower outlet and occupied space by 72, 42, 36, and 33% for the middle tower, Takhtabush, traditional tower, and the front model tower, respectively. This reduction is due to the due to internal flow resistance. The third part of the study investigates the effect of window (exist opening) position on the opposite wall. The upper, middle and lower window positions are studied and compared. The air stagnation or recirculation zone inside the ventilated space reduced from 55% with the lower window to 46% for the middle window and reached 35% for the upper window position. The Front and Takhtabush models for the one-sided wind catcher with an upper window position are highly recommended for the wind-driven natural ventilation in residential houses that are located in arid regions.

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

Effects of the Internal Flow in a Nozzle Hole on the Breakup Processes of a Liquid Jet

1997 ◽  
Vol 24 (4-6) ◽  
pp. 461-470 ◽  
Author(s):  
N. Tamaki ◽  
Keiya Nishida ◽  
Hiroyuki Hiroyasu ◽  
M. Shimizu
Keyword(s):  
Internal Flow ◽  
Liquid Jet ◽  
Nozzle Hole

Characteristics of the Internal Flow in a Diesel Injection Nozzle

1997 ◽  
Vol 24 (1-3) ◽  
pp. 34-44 ◽  
Author(s):  
J. H. Kim ◽  
Keiya Nishida ◽  
Hiroyuki Hiroyasu
Keyword(s):  
Internal Flow ◽  
Injection Nozzle ◽  
Diesel Injection

TORQUE CONVERTER INTERNAL FLOW: VISUALIZATION AND IMAGE PROCESSING

2017 ◽  
Vol 24 (1-4) ◽  
pp. 209-222
Author(s):  
Fujio Yamamoto ◽  
Ari-isa Wada ◽  
Manabu Iguchi ◽  
Masa-aki Ishikawa
Keyword(s):  
Image Processing ◽  
Flow Visualization ◽  
Internal Flow ◽  
Torque Converter
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