Modeling and Simulation
K. Jalalvandi; A. Parvareh
Abstract
In this study, the fluid flow together with solid particles has been studied using Computational Fluid Dynamics (CFD). The gas-solid flow (air and sand particles with the size of 150 µm) inside a 76.2 mm diameter pipe with various bend angles including 45, 60, 90, 120, 135, and 180° was modelled ...
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In this study, the fluid flow together with solid particles has been studied using Computational Fluid Dynamics (CFD). The gas-solid flow (air and sand particles with the size of 150 µm) inside a 76.2 mm diameter pipe with various bend angles including 45, 60, 90, 120, 135, and 180° was modelled at the fluid flow velocity of 11 m/s. The k-ω turbulence model was employed to model the flow turbulence and the E/CRC erosion model have been used to predict erosion rates. The hydrodynamics of the flow, the particles motion as well as the probable erosion regions were predicted. The CFD simulation results showed that increasing the curvature angle increases the erosion rate. While, increasing the pipe diameter, decreases the erosion rate. The maximum erosion rate was predicted at the end part of the curvature for 45 and 60 ° angles, while it was observed in the middle region for 120 and 135 ° curvatures. Finally, the maximum erosion rate for the 180 ° curvature was observed in two regions at the end of the first and second half. Using these results, precautionary considerations for the erosion, and the suitable plans for the repair and maintenance of the equipment can be offered.
Polymer Engineering and Technology,
Volume 5, Issue 2 , April 2008, , Pages 45-54
Abstract
Composites of polyaniline with calcium carbonate particles (PANI/CaCO3) with different CaCO3 content (0-40 %w/w) were prepared. Two different methods of in situ polymerization and solution mixing were used for PANI/CaCO3 composite preparation. The composite was characterized using FT-IR, SEM, electrical ...
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Composites of polyaniline with calcium carbonate particles (PANI/CaCO3) with different CaCO3 content (0-40 %w/w) were prepared. Two different methods of in situ polymerization and solution mixing were used for PANI/CaCO3 composite preparation. The composite was characterized using FT-IR, SEM, electrical conductivity measurement and cyclic voltammetry techniques. The incorporation of CaCO3 particles in polyaniline matrix in both methods of composite preparation was confirmed by FTIR results. Electrical conductivity measurements showed that the conductivity of the composite decreases by increasing the CaCO3 loading in polyaniline. Also, the anticorrosive property of the PANI/CaCO3 composite coating on iron samples was investigated in various corrosive environments. According to the results, the corrosion rate or corrosion current of PANI/CaCO3 composite coated iron coupons was much lower (96.75%) than polyaniline coated samples. Also, results showed that the corrosion current of composite coated samples varies with the variation of the CaCO3 content in composite coating, and the optimum CaCO3 content of composite coating to achieve the best anticorrosive performance on iron is 10 %w/w.