A novel method to determine flow-accelerated corrosion rate based on fluid structure interaction

2013 ◽  
Vol 65 (11) ◽  
pp. 1120-1127 ◽  
Author(s):  
X. L. Zhu ◽  
L. X. Zhu ◽  
X. F. Lu ◽  
X. Ling
Keyword(s):  
Corrosion Rate ◽  
Fluid Structure Interaction ◽  
Accelerated Corrosion ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Novel Method ◽  
Flow Accelerated Corrosion

Fluid Structure Interaction Analysis on Wall Thinned Pipes

2006 ◽  
Vol 321-323 ◽  
pp. 670-673 ◽  
Author(s):  
Yoon Suk Chang ◽  
Ki Hun Song ◽  
Sang Min Lee ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Nuclear Industry ◽  
Accelerated Corrosion ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Pressure Distributions ◽  
Critical Issues ◽  
Asme Code ◽  
Flow Accelerated Corrosion

The wall thinning due to erosion, corrosion and flow accelerated corrosion is one of critical issues in nuclear industry. To secure against loss of integrity of pipes with a flaw, ASME Code Section III and Code Case N-597 etc have been used in design and operating stages, respectively. However, despite of their inherent conservatisms, it may reach unanticipated accidents due to degradation at local region. In this paper, a new evaluation scheme is suggested to estimate load-carrying capacities of wall thinned pipes. At first, computational fluid dynamics analyses employing steady-state and incompressible flow are carried out to determine pressure distributions in accordance with conveying fluid. Then, the discriminate pressures are applied as input condition of structural finite element analyses to calculate local stresses at the deepest point. A series of combined analyses were performed for different fluid flow velocities as well as d/t, Rm/t and l/t ratios. The efficiency of proposed scheme was proven from comparison with conventional analyses results and it is recommended to consider the fluid structure interaction effect for exact integrity evaluation.

Instability of a Cantilevered Flexible Plate in Inviscid Channel Flow

2006 ◽  
Author(s):  
Richard M. Howell ◽  
Anthony D. Lucey ◽  
Peter W. Carpenter
Keyword(s):  
Channel Flow ◽  
Fluid Structure Interaction ◽  
Flexible Plate ◽  
Mean Flow ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Central Surface ◽  
New Type ◽  
Novel Method ◽  
Stiffness And Damping

A novel method for calculating the linear fluid-structure interaction of a cantilevered flexible plate centrally positioned in ideal channel flow, incorporating the effects of vorticity shed downstream, is described. When the channel walls are moved far apart, predictions of the critical velocity show good correlation with other published work. For the first time, detailed numerical investigation of the effect on this fluid-structure interaction of channel walls, a rigid central surface (upstream and adjacent to the flexible plate), unsteady mean flow and the variation of stiffness and damping properties along the flexible plate have been quantified. Of central importance is the application of the unsteady model to the investigation of the human snoring phenomenon. Further insight into the operation of two types of snore is made and a new type of snore is discovered that originates from the time-dependent effects of inhalation.

scholarly journals FLUID–STRUCTURE-INTERACTION ANALYSIS FOR WELDED PIPES WITH FLOW-ACCELERATED CORROSION WALL THINNING

2016 ◽  
Vol 5 (1) ◽  
pp. 49-65 ◽  
Author(s):  
Lan Sun ◽  
Yuqing Ding
Keyword(s):  
Residual Stresses ◽  
Fluid Structure Interaction ◽  
Combined Effects ◽  
Resistant Material ◽  
Accelerated Corrosion ◽  
Welded Structures ◽  
Entrance Effect ◽  
Structure Interaction ◽  
Wall Thinning ◽  
Flow Accelerated Corrosion

The flow-accelerated corrosion (FAC) entrance effect results in enhanced wall thinning immediately downstream of a weld if the weld connects an upstream FAC-resistant material with a downstream less resistant material. The weld regions, especially those with local repairs, are susceptible to cracking due to the high residual stresses induced by fabrication. The combined effects of the FAC entrance effect and high stresses at a weld might compromise the structural integrity of the piping and lead to a failure. Weld degradation by FAC entrance effect has been observed at nuclear and fossil power plants. This paper describes an application using fluid–structure-interaction (FSI) modelling to study the combined effects of FAC wall thinning, weld residual stresses, and in-service loads on welded structures. Simplified cases analyzed were based on CANDU outlet feeder conditions. The analysis includes the flow and mass transfer modelling of the FAC entrance effect using computational fluid dynamics (CFD) and nonlinear structural analyses of the welded structures with wall thinning and an assumed weld residual stress and strain distribution. The FSI analyses were performed using ANSYS Workbench, an integrated platform that enables the coupling of CFD and structural analysis solutions. The obtained results show that the combination of FAC, weld residual stresses, in-service loads (including the internal pressure) and (or) extreme loads could cause high stresses and affect the integrity of the welded pipes. The present work demonstrated that the FSI modelling can be used as an effective approach to assess the integrity of welded structures.

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