scholarly journals Excitation of piping systems from fully turbulent internal flow

1985 ◽  
Vol 78 (S1) ◽  
pp. S43-S43
Author(s):  
J. M. Cuschieri
Keyword(s):  
Internal Flow ◽  
Piping Systems

A Methodology for Assessment of Internal Flow-Induced Vibration (FIV) in Subsea Piping Systems

2011 ◽  
Author(s):  
Yetzirah Urthaler ◽  
Lyle E. Breaux ◽  
Scot I. McNeill ◽  
Eric M. Luther ◽  
Julian Austin ◽  
...  
Keyword(s):  
Vibration Spectrum ◽  
Internal Flow ◽  
Measured Data ◽  
Model Verification ◽  
Modal Parameters ◽  
Response Analysis ◽  
Fe Model ◽  
Vibration Data ◽  
Forcing Function ◽  
Piping Systems

A methodology is presented for assessing internal flow-induced vibrations (FIV) in subsea piping systems. Finite Element (FE) models are constructed for the subject piping systems, including insulation, internal hydrocarbon weight and added mass of the surrounding sea water. Operating vibration data are measured using ROV-deployable accelerometer loggers clamped directly to the piping systems. The measured data are processed, analyzed and used for two purposes: model verification and dynamic response correlation. Modal parameters are extracted from the measured data and compared to the modal parameters computed from the structural FE model. The model is refined until the frequencies and mode shape errors are within the desired tolerance. The measured data are then used to derive a representative forcing function for use with frequency-domain random response analysis. The forcing function is derived such that the properties of the predicted vibration spectrum match those of the measured vibration spectrum for all measurement locations. The method presented herein provides a novel semi-empirical technique for calibrating FE models to make fatigue life predictions for subsea piping systems using measured vibration data.

Fluidelastic Instability of Flexible Tubular Cylinders Subjected to Two-Phase Internal Flow

2003 ◽  
Author(s):  
Christine Monette ◽  
Michel J. Pettigrew
Keyword(s):  
Internal Flow ◽  
Gas Flows ◽  
Two Phase Flows ◽  
Two Phase ◽  
Void Fractions ◽  
Fluidelastic Instability ◽  
Piping Systems ◽  
Phase Liquid ◽  
Series Of Experiments ◽  
Different Diameters

The fluidelastic instability behaviour of flexible cylinders subjected to internal single-phase (liquid or gas) flows is now reasonably well understood. Although many piping systems operate in two-phase flows, so far very little work has been done to study their dynamic behaviour under such flows. This paper presents the results of a series of experiments to study the fluidelastic instability behaviour of flexible tubular cylinders subjected to two-phase internal flow. Several flexible cylinders of different diameters, lengths and flexural rigidities were tested over a broad range of flow velocities and void fractions in an air-water loop to simulate two-phase flows. Well-defined fluidelastic instabilities were observed in two-phase flows. The existing theory to formulate the fluidelastic behaviour under internal flow was developed further to take into account two-phase flow. The agreement between the experimental results and the modified theory is remarkably good. However, it depends on using an appropriate model to formulate the characteristics of the two-phase flows.

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

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

THE INTERNAL FLOW FIELD ASSOCIATED WITH YAWED THREE-DIMENSIONAL RECTANGULAR CAVITIES

2000 ◽  
Vol 7 (3) ◽  
pp. 14
Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Internal Flow

Finite element methods for internal flow calculations

1983 ◽  
Author(s):  
W. HABASHI ◽  
M. HAFEZ ◽  
P. KOTIUGA
Keyword(s):  
Finite Element ◽  
Finite Element Methods ◽  
Internal Flow
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