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Modeling and Simulation for PIG Flow Control in Natural Gas Pipeline
Nguyen, Tan-Tien,Kim, Sang-Bong,Yoo, Hui-Ryong,Park, Yong-Woo The Korean Society of Mechanical Engineers 2001 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.15 No.8
This paper deals with dynamic analysis of Pipeline Inspection Gauge (PIG) flow control in natural gas pipelines. The dynamic behaviour of PIG depends on the pressure differential generated by injected gas flow behind the tail of the PIG and expelled gas flow in front of its nose. To analyze dynamic behaviour characteristics (e.g. gas flow, the PIG position and velocity) mathematical models are derived. Tow types of nonlinear hyperbolic partial differential equations are developed for unsteady flow analysis of the PIG driving and expelled gas. Also, a non-homogeneous differential equation for dynamic analysis of the PIG is given. The nonlinear equations are solved by method of characteristics (MOC) with a regular rectangular grid under appropriate initial and boundary conditions. Runge-Kutta method is used for solving the steady flow equations to get the initial flow values and for solving the dynamic equation of the PIG. The upstream and downstream regions are divided into a number of elements of equal length. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. Simulation is performed with a pipeline segment in the Korea gas corporation (KOGAS) low pressure system. Ueijungboo-Sangye line. The simulation results show that the derived mathematical models and the proposed computational scheme are effective for estimating the position and velocity of the PIG with a given operational condition of pipeline.
Flexural-torsional vibration and buckling of thin-walled bi-directional functionally graded beams
Nguyen, Tan-Tien,Lee, Jaehong Elsevier 2018 Composites Part B, Engineering Vol.154 No.-
<P><B>Abstract</B></P> <P>The paper introduces an analysis of flexural-torsional vibration and buckling of thin-walled bi-directional FG beams. Several cross sections have been conducted such as mono-symmetric I-shaped and channel sections in which material properties are assumed to vary across blade thickness and along axial direction. Governing equations and finite element model are developed. The model is capable of capturing all complex eigenvalue problems, also provides a highly accurate prediction of vibrational shapes and buckling capacity. Since the material changes, the obtained results reflect the relative relation between the behaviors of the beam and the transformation of internal properties, for example, Young's modulus, density, etc. Effects of gradient parameters on the vibrational frequencies or limit loads of a thin-walled bi-directional FG beam under various configurations and boundary conditions have also been parametrically studied.</P>
Nguyen, Tan-Tien,Lee, Jaehong Elsevier 2018 Composite structures Vol.191 No.-
<P><B>Abstract</B></P> <P>The paper aims to present an analysis of static behaviors and interactive geometric interpretation for modeling of thin-walled bi-directional functionally graded beams regarding monosymmetric I- and channel-sections. Several material distributions based on a typical power law are provided. The model of thin-walled bi-directional FG beams was originally developed from Vlasov’s theory in which warping has been taken into account. Since the variation of constituent phases such as metal or ceramic in both longitudinal and through-the-thickness directions, properties of the thin-walled beam have considerably changed. It is shown that in each cross section, center of gravity and shear center are highly sensitive to geometries, materials and thus need to be reconsidered. For that reason the external load cannot be randomly applied. Effects of gradient parameters on the static behavior of a thin-walled bi-directional FG beam under various loadings and boundary conditions have also been parametrically studied.</P>
Modeling and Simulation for PIG with Bypass Flow Control in Natural Gas Pipeline
Nguyen, Tan-Tien,Kim, Sang-Bong,Yoo, Hui-Ryong,Park, Yong-Woo The Korean Society of Mechanical Engineers 2001 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.15 No.9
This paper introduces modeling and simulation results for pipeline inspection gauge (PIG) with bypass flow control in natural gas pipeline. The dynamic behaviour of the PIG depends on the different pressure across its body and the bypass flow through it. The system dynamics includes: dynamics of driving gas flow behind the PIG, dynamics of expelled gas in front of the PIG, dynamics of bypass flow, and dynamics of the PIG. The bypass flow across the PIG is treated as incompressible flow with the assumption of its Mach number smaller than 0.45. The governing nonlinear hyperbolic partial differential equations for unsteady gas flows are solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used for solving the steady flow equations to get initial flow values and the dynamic equation of the PIG. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. Simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of the PIG with bypass flow under given operational conditions of pipeline.
Screening and Production of Manganese Peroxidase from Fusarium sp. on Residue Materials
( Nguyen Duc Huy ),( Nguyen Thi Thanh Tien ),( Le Thi Huyen ),( Hoang Tan Quang ),( Truong Quy Tung ),( Nguyen Ngoc Luong ),( Seung-moon Park ) 한국균학회 2017 Mycobiology Vol.45 No.1
In this study, we report the manganese peroxidase production ability from a Fusarium sp. strain using an inexpensive medium of agriculture residues of either rice straw or wood chips as carbon source. The highest manganese peroxidase activity on rice straw medium and on wood chips was 1.76 U/mL by day 9 and 1.91 U/mL by day 12, respectively.