The Experts below are selected from a list of 585 Experts worldwide ranked by ideXlab platform
Ezzeddine Hadj Taieb - One of the best experts on this subject based on the ideXlab platform.
-
impedance method for modeling and Locating Leak with cylindrical geometry
2012Co-Authors: Lazhar Ayed, Lamjed Hadj Taieb, Ezzeddine Hadj TaiebAbstract:This paper uses transient frequency methods to locate a Leak in a pipeline system when a Leak is modeled as a small cylindrical pipe element open to atmospheric pressure on one end. The impedance of the Leak as a small cylindrical pipe is included in the transfer function equation at the closed valve in a reservoir-pipe-valve system. The impedance diagram of this system with cylindrical Leak is plotted and analyzed; the influence of the pipe thickness on Leak locations is studied. The numerical study relying on impedance method shows that the cylindrical Leak geometry approach allows secondary peaks to be detected only for thick pipes. By imposing a periodic pattern on the resonant responses, the Leak with cylindrical geometry can be located and its location is based on an empirical relation. The computed results show satisfactory agreement with previous works when Leak is modeled by a circular orifice.
Nurul Fatiehah Adnan - One of the best experts on this subject based on the ideXlab platform.
-
Leak detection in gas pipeline based on time-frequency analysis
2016Co-Authors: Nurul Fatiehah AdnanAbstract:Pipelines are very important part of any engineering infrastructure. Gas Leak is a prominent problem associated with pipelines and it is inevitable in many systems. Prevention of Leak is important since gas Leak will lead to deficiency and also effects the environment. The safety is one of the main reasons why Leak detection is popular in research and development sector. Subsequently, many researchers studied various available methods for Leak detection in gas pipeline. One of them is acoustic method. Leak in gas pipelines can be detected and located precisely using certain sensor. However, high fast alarm rate is the main problem in detecting Leak. Non-stationary signal is produced by gas flowing in the pipeline, making the analysis of signal becomes more difficult. The scope of this research is detecting and Locating Leak in straight pipeline and L-bend. The experiments were conducted by injecting the sinusoidal wave into the pipeline and the reflection of the signal is collected by using a microphone. The data is acquired by DASYlab and analysed using Matlab software. The important element in this study is the signal echoes produced by the disturbance of gas flow with Leak (defect) or Lbend (feature). Analysing the signal echoes is very closely related to signal processing. In conjunction to that, Hilbert transform (HT) and Ensemble Empirical Mode Decomposition (EEMD) or simply called as Hilbert Huang Transform (HHT) is applied to produce robust results. EEMD is adopted to decompose the signal into IMFs and each IMF is analysed using HT to get instantaneous phase and instantaneous frequency. Besides, the study has shown that HT provides accurate Leak location with application of instantaneous phase and instantaneous frequency. Hilbert spectrum (HS) has successfully displayed the energy-time-frequency distribution in proper presentation. The percentage error for all experiment is below 5 percent. In conclusion, HHT is a promising signal processing method that can be used to analyse the echoes acquired from experiments, producing accurate Leak location with this method, it is possible to identify Leaks and also features in a pipeline network with acceptable errors for both Leak and L-bend
Lazhar Ayed - One of the best experts on this subject based on the ideXlab platform.
-
impedance method for modeling and Locating Leak with cylindrical geometry
2012Co-Authors: Lazhar Ayed, Lamjed Hadj Taieb, Ezzeddine Hadj TaiebAbstract:This paper uses transient frequency methods to locate a Leak in a pipeline system when a Leak is modeled as a small cylindrical pipe element open to atmospheric pressure on one end. The impedance of the Leak as a small cylindrical pipe is included in the transfer function equation at the closed valve in a reservoir-pipe-valve system. The impedance diagram of this system with cylindrical Leak is plotted and analyzed; the influence of the pipe thickness on Leak locations is studied. The numerical study relying on impedance method shows that the cylindrical Leak geometry approach allows secondary peaks to be detected only for thick pipes. By imposing a periodic pattern on the resonant responses, the Leak with cylindrical geometry can be located and its location is based on an empirical relation. The computed results show satisfactory agreement with previous works when Leak is modeled by a circular orifice.
Muhammad Sabih - One of the best experts on this subject based on the ideXlab platform.
-
measurement error sensitivity analysis for detecting and Locating Leak in pipeline using ann and svm
International Multi-Conference on Systems Signals and Devices, 2014Co-Authors: Mohammad Tariq Nasir, Muhammad F Mysorewala, Lahouari Cheded, Bilal A Siddiqui, Muhammad SabihAbstract:This paper presents an approach for detecting, Locating and estimating the size of Leak in a pipeline using pressure sensors, differential pressure sensors and flow-rate sensors. To overcome the problem with existing approaches we use differential pressure sensors that detect small change in pressure in order to detect small change in Leak size. The pipeline system is modeled and simulated in EPANET software, and the input-output data acquired from it (i.e. sensor measurements and the Leak locations and sizes) are used in MATLAB and DTREG software to develop Artificial Neural Network (ANN) and Support Vector Machines (SVM) models. Comparison of results shows that SVM is less sensitive and more stable to noise increment than ANN. However the performance of ANN is better with very small noises.
Lamjed Hadj Taieb - One of the best experts on this subject based on the ideXlab platform.
-
impedance method for modeling and Locating Leak with cylindrical geometry
2012Co-Authors: Lazhar Ayed, Lamjed Hadj Taieb, Ezzeddine Hadj TaiebAbstract:This paper uses transient frequency methods to locate a Leak in a pipeline system when a Leak is modeled as a small cylindrical pipe element open to atmospheric pressure on one end. The impedance of the Leak as a small cylindrical pipe is included in the transfer function equation at the closed valve in a reservoir-pipe-valve system. The impedance diagram of this system with cylindrical Leak is plotted and analyzed; the influence of the pipe thickness on Leak locations is studied. The numerical study relying on impedance method shows that the cylindrical Leak geometry approach allows secondary peaks to be detected only for thick pipes. By imposing a periodic pattern on the resonant responses, the Leak with cylindrical geometry can be located and its location is based on an empirical relation. The computed results show satisfactory agreement with previous works when Leak is modeled by a circular orifice.
