Effect of Pipe Wall Roughness On Porous Breakwater Structure On Wave Deformation

The default roughness parameter values used in industry to determine the pressure loss through small diameter pipeline systems are much higher than the values employed in typical large diameter gas transmission and lateral systems. It is uncertain whether these higher roughness values are due to higher topological roughness of the internal wall of the small diameter pipes or if they are a result of other factors. Measurements were taken on 17 small diameter pipe samples in order to evaluate the pipe-wall roughness parameter. A model to calculate the effective roughness parameter, which takes into account pressure losses due to the measured roughness as well as internal welds and scaling, has been developed. The effective roughness parameter of these samples is found to range from 20.4μm to 62.9μm, an increase of 11.0μm to 23.3μm over the measured pipe-wall roughness parameter. This range of effective roughness parameters agrees well with the default range of 35μm to 65μm used in industry, as well as the literature quoted range for clean pipe of 40μm to 100μm. The measured roughness parameter on average increases with increasing nominal pipe size, a result that may be a characteristic of the extrusion or hot-rolling processes used to manufacture small diameter pipes. Additionally, there is a large variation in the measured roughness parameters of pipe samples of the same nominal pipe size, indicating that surface roughness can vary depending on the manufacturing source of these pipes.

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Application of Error-in-Variable Model (EVM) for Estimating Gas Pipeline Internal Wall Roughness Before and After Pigging

Volume 3: Operations, Monitoring and Maintenance; Materials and Joining ◽

10.1115/ipc2016-64080 ◽

2016 ◽

Author(s):

Teresa Leung ◽

Joel Smith ◽

Trevor Glen ◽

Will Runciman

Keyword(s):

Surface Roughness ◽

Pipe Wall ◽

Surface Condition ◽

Internal Surface ◽

Measured Data ◽

Wall Roughness ◽

Wall Surface ◽

Internal Wall ◽

Variable Model ◽

Before And After

Gas pipeline internal surface typically undergoes degradation for a variety of reasons such as fouling of the pipe inner surface, erosion, corrosion and deposits of objectionable materials that occasionally enter the gas stream at receipt points. Accurate monitoring of the pipe internal surface condition can hugely benefit the planning of cleaning activities. Theoretically the pipe wall roughness for a given pipe segment can be extracted based on measured flow data and other system parameters. The challenge lies in the fact that measured data all contain varying degrees of uncertainty, and the system becomes more complex to analyze when it contains different segments connected in series or parallel like many typical gas gathering and lateral networks. This paper demonstrates the application of the Error-in-Variable Model (EVM) using the Markov Chain Monte Carlo (MCMC) solution method in analyzing a complex pipeline network on the TransCanada NGTL System. EVM, a well-established Bayesian parameter estimation technique, accounts for uncertainties in the measured variables, such as flow and pressure data, when determining the most probable estimates of unknown parameters such as pipe internal wall surface roughness. In this work, the EVM problem is solved using the MCMC Metropolis-Hastings algorithm. The MCMC approach is demonstrated to be robust, easy to implement and capable of handling large quantities of data. It has the potential to analyze complex networks and monitor the pipe wall surface condition on-line with SCADA data. Using this method, the internal wall surface roughness for the segments of interest in this network were extracted from measured data collected before and after the pigging operation. Results demonstrate the model’s capability in estimating the degradation of the pipe wall internal surface and the effectiveness of pigging. Details on implementation and challenges in applying such methodology to analyze complex gas networks are discussed.

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Effect of Wall Roughness and Flow Velocity on Water Hammer

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1014.185 ◽

2014 ◽

Vol 1014 ◽

pp. 185-191

Author(s):

Qing Zheng Meng ◽

Cheng Yang ◽

Li Sheng Liu ◽

Zhen Wang

Keyword(s):

Flow Velocity ◽

Pressure Wave ◽

Pipe Wall ◽

Influence Factors ◽

Normal Pressure ◽

Water Hammer ◽

Simulation Software ◽

Wall Roughness ◽

Great Loss ◽

Waveform Amplitude

Water hammer can occur in any fluid pipeline systems. The pressure caused by water hammer are far exceeding the pressure range of the pipe limit, and it can lead to the failure or fracture of the pipeline. Since a great loss has been caused by that, two influence factors (flow velocity and roughness of the pipe-wall) associated with water hammer have been performed by using the numerical simulation software CFX. Analysis of the results show that each factor effects differently in waveform, amplitude, period, attenuation of the water hammer wave. The different velocities only influences the peak of pressure wave but not the waveform and period. The pressure reduction as the increase of roughness can be neglected compared to the normal pressure.

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Wave reflection and transmission test with pipe wall roughness and without roughness on the perforated breakwater

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/419/1/012141 ◽

2020 ◽

Vol 419 ◽

pp. 012141

Author(s):

A M Syamsuri ◽

D Suriamihardja ◽

M A Thaha ◽

T Rachman

Keyword(s):

Wave Reflection ◽

Pipe Wall ◽

Wall Roughness ◽

Reflection And Transmission ◽

Perforated Breakwater ◽

Transmission Test

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Experiment and fitting calculation of migration critical velocity of small-sized sedaiment particles erosion in rainwater pipeline

Water Science & Technology Water Supply ◽

10.2166/ws.2020.341 ◽

2020 ◽

Author(s):

Cuiyun Liu ◽

Yanzhi Chen ◽

Yuting Yang ◽

Jingqin Zhou ◽

Yiyang Wang ◽

...

Keyword(s):

Mathematical Models ◽

Critical Velocity ◽

Pipe Wall ◽

Wall Roughness ◽

Sediment Thickness ◽

Good Consistency ◽

Sediment Particles ◽

The Difference ◽

Large Flow ◽

Strong Erosion

Abstract The migration critical velocity of small-sized sediment particles was investigated through experiments under different particle sizes, pipe wall roughness, and sediment thickness. Such experiments were carried out to simulate the erosion process of small-sized sediment particles in rainwater pipeline during rainfall. The mathematical models were established via quadratic fitting to calculate the critical velocity of migration. Results showed that small particles had powerful cohesive force, and aggregates had strong erosion resistance. So, for the small-sized particles (in the range of 0.33–0.83 mm), the smaller the particle size was, the larger the critical velocity was. When the pipe wall roughness was large, the ‘starting’ particle resistance was high. A large flow dynamic was needed to overcome such resistance. Thus, the critical velocity was great. The critical velocity was also large when the sediment thickness was large. The difference rate between the critical velocity calculated by mathematical models and the measured value was within the range of −3.60% to 5.33% and had good consistency. Under the research conditions, the critical velocity ranges of the four commonly used pipes, namely, plexiglass, steel/PVC, galvanized/clay, and cast iron pipes, were calculated.

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The Effect of Internal Pipe Wall Roughness on the Accuracy of Clamp-On Ultrasonic Flowmeters

IEEE Transactions on Instrumentation and Measurement ◽

10.1109/tim.2018.2834118 ◽

2019 ◽

Vol 68 (1) ◽

pp. 65-72 ◽

Cited By ~ 10

Author(s):

Xiaotang Gu ◽

Frederic Cegla

Keyword(s):

Pipe Wall ◽

Wall Roughness

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The uncertainties induced by internal pipe wall roughness on the measurements of clamp-on ultrasonic flow meters

2019 IEEE International Ultrasonics Symposium (IUS) ◽

10.1109/ultsym.2019.8926062 ◽

2019 ◽

Author(s):

Xiaotang Gu ◽

Frederic Cegla

Keyword(s):

Pipe Wall ◽

Wall Roughness ◽

Flow Meters

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Investigation of the Effects of Pipe Wall Roughness and Pipe Diameter on the Decompression Wave Speed in Natural Gas Pipelines

Volume 3: Materials and Joining ◽

10.1115/ipc2012-90345 ◽

2012 ◽

Cited By ~ 5

Author(s):

C. Lu ◽

G. Michal ◽

A. Elshahomi ◽

A. Godbole ◽

P. Venton ◽

...

Keyword(s):

Wave Speed ◽

Pipe Wall ◽

Experimental Results ◽

Pipe Diameter ◽

Wall Roughness ◽

One Dimensional ◽

Natural Gas Pipelines ◽

Decompression Wave ◽

Dynamic Simulation Model ◽

Smooth Pipe

The shock tube experimental results have shown clearly that the decompression wave was slowed down in a pipe with a rough inner surface relative to that in a smooth pipe under comparable conditions. In the present paper a one-dimensional dynamic simulation model, named EPDECOM, was developed to investigate the effects of pipe wall roughness and pipe diameter on the decompression wave speed. Comparison with experimental results showed that the inclusion of frictional effects led to a better prediction than that of the widely used model implemented in GASDECOM. EPDECOM simulation results showed that the effect of roughness on the decompression wave speed is significant for pipe diameters less than 250 mm. However the decompression wave speed is nearly independent of the roughness for diameters above 250 mm as the frictional effect becomes negligible at such diameters.

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