scholarly journals Correlation between Flow Accelerated Corrosion and Wall Shear Stress Downstream from an Orifice

2013 ◽  
Vol 7 (3) ◽  
pp. 138-147 ◽  
Author(s):  
Yoichi UTANOHARA ◽  
Yukinori NAGAYA ◽  
Akira NAKAMURA ◽  
Michio MURASE ◽  
Koichi KAMAHORI
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Accelerated Corrosion ◽  
Wall Shear ◽  
Flow Accelerated Corrosion

Prediction of Flow-Accelerated Corrosion/Erosion in High-Speed Ejectors Using a CFD Model

2019 ◽  
Author(s):  
Saurish Das ◽  
Suranjan Sarkar ◽  
Gary H. Lee ◽  
Ong Junxiong
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Droplet Size ◽  
Impact Angle ◽  
Multiphase Model ◽  
Liquid Droplets ◽  
Cfd Model ◽  
Accelerated Corrosion ◽  
Wall Shear ◽  
Flow Accelerated Corrosion

Abstract In high-velocity ejector systems containing liquid droplets, ejector walls are sometimes damaged by flow-accelerated corrosion/erosion. Velocity, droplet size, impact angle etc. are the most important parameters affecting flow-accelerated (FA) corrosion/erosion. In our plant operation, we had experienced FA corrosion/erosion and consequent failure even with very low impact angle. To understand the leak/ failure, we have adopted the Euler-Euler multiphase model-based CFD approach. In the Euler-Euler multiphase model, the liquid droplets are modelled as dispersed phase while the gas-steam is modelled as a continuous phase. To capture the droplet dynamics very accurately, appropriate correlations for drag, lift and wall lubrication force have been chosen. In CFD simulations we have observed liquid film formation at the ejector wall. The liquid film moves along the ejector wall creates a very high wall shear-stress. In the location of high wall shear-stress, one can expect high FA corrosion/erosion and consequent leak. Qualitative comparison of the X-ray image of the actual equipment with the CFD results for wall-shear stress shows very good agreement in terms of predicting leak location. Moreover, we have varied the droplet size and the liquid fraction in the upstream of the ejector. Qualitatively we have observed that with increase in droplet size the material removal rate increases, however, the affected area of the leak decreases. The more liquid in the system increases the wall-shear stress very rapidly. The present CFD model is useful for predicting the leak-prone location and taking predictive actions (e.g. cladding the wall with a high-grade material).

S053074 Relation between Flow Accelerated Corrosion and Wall Shear Stress Downstream from an Orifice in a Circular Pipe

2012 ◽  
Vol 2012 (0) ◽  
pp. _S053074-1-_S053074-4
Author(s):  
Yoichi UTANOHARA ◽  
Yukinori NAGAYA ◽  
Akira NAKAMURA ◽  
Michio MURASE ◽  
Takahiro KIWATA ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Circular Pipe ◽  
Accelerated Corrosion ◽  
Wall Shear ◽  
Flow Accelerated Corrosion

Disturbed Flow and Flow-Accelerated Corrosion in Oil and Gas Production

1998 ◽  
Vol 120 (1) ◽  
pp. 72-77 ◽  
Author(s):  
K. D. Efird
Keyword(s):  
Mass Transfer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Oil And Gas ◽  
Steel Corrosion ◽  
Flow Conditions ◽  
Accelerated Corrosion ◽  
Disturbed Flow ◽  
Wall Shear ◽  
Flow Accelerated Corrosion

The effect of fluid flow on corrosion of steel in oil and gas environments involves a complex interaction of physical and chemical parameters. The basic requirement for any corrosion to occur is the existence of liquid water contacting the pipe wall, which is primarily controlled by the flow regime. The effect of flow on corrosion, or flow-accelerated corrosion, is defined by the mass transfer and wall shear stress parameters existing in the water phase that contacts the pipe wall. While existing fluid flow equations for mass transfer and wall shear stress relate to equilibrium conditions, disturbed flow introduces nonequilibrium, steady-state conditions not addressed by these equations, and corrosion testing in equilibrium conditions cannot be effectively related to corrosion in disturbed flow. The problem in relating flow effects to corrosion is that steel corrosion failures in oil and gas environments are normally associated with disturbed flow conditions as a result of weld beads, pre-existing pits, bends, flanges, valves, tubing connections, etc. Steady-state mass transfer and wall shear stress relationships to steel corrosion and corrosion testing are required for their application to corrosion of steel under disturbed flow conditions. A procedure is described to relate the results of a corrosion test directly to corrosion in an operation system where disturbed flow conditions are expected, or must be considered.

Correction: Development of a Two-Dimensional Wall Shear Stress Sensor for Wind Tunnel Applications

2019 ◽  
Author(s):  
Brett Freidkes ◽  
David A. Mills ◽  
Casey Keane ◽  
Lawrence S. Ukeiley ◽  
Mark Sheplak
Keyword(s):  
Shear Stress ◽  
Wind Tunnel ◽  
Wall Shear Stress ◽  
Two Dimensional ◽  
Stress Sensor ◽  
Shear Stress Sensor ◽  
Wall Shear

Basic study on estimation method of wall shear stress in common carotid artery using blood flow imaging

2020 ◽  
Vol 59 (SK) ◽  
pp. SKKE16 ◽  
Author(s):  
Ryo Nagaoka ◽  
Kazuma Ishikawa ◽  
Michiya Mozumi ◽  
Magnus Cinthio ◽  
Hideyuki Hasegawa
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Carotid Artery ◽  
Wall Shear Stress ◽  
Common Carotid Artery ◽  
Estimation Method ◽  
Flow Imaging ◽  
Basic Study ◽  
Blood Flow Imaging ◽  
Wall Shear
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