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The numerical results of local scour for bridge piers are significantly affected by the inlet turbulent boundary conditions. A novel self-sustaining model (SSM) and corresponding the new inlet turbulent boundary conditions are proposed to quickly obtain a stable flow field of horizontal homogeneity. The Reynolds averaged Navier-Stokes (RANS) equations, and standard k-ԑ turbulence model are employed to solve the complex flow around the bridge piers. Based on the sediment transport model considering the effect of the arbitrary slope of riverbed and the collapse of sediment, the dynamic evolution process of local scouring around bridge piers is simulated. Then, the applicability of the numerical approach for local scour around bridge pier is validated by the flume test comparing with the flow pattern, the maximum scour depth and the morphology of scour pit. Finally, the influence factors of local scour for bridge piers including common pier shapes and different angle of attack are studied. The numerical results indicate that the proposed SSM can develop homogeneous isotropic turbulence to fine simulate local scour with prescribed inlet turbulent boundary conditions. The established sediment collapse model can reasonably reflect the collapse process in scouring. Importantly, the proposed numerical methods can provide a reasonable prediction of maximum scour depth. In addition, the performances of the local scouring are greatly sensitive to the pier shape and the angle of attack. The inflow parallelling to piers or choosing appropriate pier shape helpful to ease the scour.
Peng Yu; Lingke Zhu. Numerical simulation of local scour around bridge piers using novel inlet turbulent boundary conditions. Ocean Engineering 2020, 218, 108166 .
AMA StylePeng Yu, Lingke Zhu. Numerical simulation of local scour around bridge piers using novel inlet turbulent boundary conditions. Ocean Engineering. 2020; 218 ():108166.
Chicago/Turabian StylePeng Yu; Lingke Zhu. 2020. "Numerical simulation of local scour around bridge piers using novel inlet turbulent boundary conditions." Ocean Engineering 218, no. : 108166.
Previous studies have showed that rock asphalt (RA) or diatomite were used to modify the petroleum bitumen. This paper presents the findings from a study conducted to evaluate the potential impact of RA and diatomite on the rheological characteristics of bitumen composites. RA and diatomite with three different dosages were added into the petroleum bitumen: 18% RA, 13% RA+7% diatomite, and 16% RA+9% diatomite by weight. The rheological characteristics of the RA and diatomite modified bitumens were evaluated in this study. The tests conducted included temperature sweep and frequency sweep tests with a dynamic shear rheometer (DSR), a Brookfield rotation viscosity test, and a scanning electron microscope test. The research showed that the addition of RA and diatomite to petroleum bitumen considerably increased the apparent viscosity, dynamic shear modulus, and rutting resistance in bitumen specimens. However, the DSR test indicated a slight reduction in the fatigue performance of composites made of RA and diatomite modified bitumens. Overall, RA and diatomite are good modifiers for petroleum bitumen for a performance improvement.
Wentong Huang; Duanyi Wang; Peiyong He; Xiang Long; Bing Tong; Jun Tian; Peng Yu. Rheological Characteristics Evaluation of Bitumen Composites Containing Rock Asphalt and Diatomite. Applied Sciences 2019, 9, 1023 .
AMA StyleWentong Huang, Duanyi Wang, Peiyong He, Xiang Long, Bing Tong, Jun Tian, Peng Yu. Rheological Characteristics Evaluation of Bitumen Composites Containing Rock Asphalt and Diatomite. Applied Sciences. 2019; 9 (5):1023.
Chicago/Turabian StyleWentong Huang; Duanyi Wang; Peiyong He; Xiang Long; Bing Tong; Jun Tian; Peng Yu. 2019. "Rheological Characteristics Evaluation of Bitumen Composites Containing Rock Asphalt and Diatomite." Applied Sciences 9, no. 5: 1023.