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Herschel–Bulkley fluid
About: Herschel–Bulkley fluid is a research topic. Over the lifetime, 1946 publications have been published within this topic receiving 49318 citations.
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TL;DR: In this article , the authors explore the accuracy and robustness of the CFD code in simulating the flow of Herschel-Bulkley fluids, including power-law, Bingham and Newtonian fluids as particular cases.
Abstract: The ship’s resistance and manoeuvrability in shallow waters can be adversely influenced by the presence of fluid mud layers on the seabed of ports and waterways. Fluid mud exhibits a complex non-Newtonian rheology that is often described using the Herschel–Bulkley model. The latter has been recently implemented in a maritime finite-volume CFD code to study the manoeuvrability of ships in the presence of muddy seabeds. In this paper, we explore the accuracy and robustness of the CFD code in simulating the flow of Herschel–Bulkley fluids, including power-law, Bingham and Newtonian fluids as particular cases. As a stepping stone towards the final maritime applications, the study is carried out on a classic benchmark problem in non-Newtonian fluid mechanics: the laminar flow around a sphere. The aim is to test the performance of the non-Newtonian solver before applying it to the more complex scenarios. Present results could also be used as reference data for future testing. Flow simulations are carried out at low Reynolds numbers in order to compare our results with an extensive collection of data from the literature. Results agree both qualitatively and quantitatively with literature. Difficulties in the convergence of the iterative solver emerged when simulating Bingham and Herschel–Bulkley flows. A simple change in the interpolation of the apparent viscosity has mitigated such difficulties. The results of this work, combined with our previous code verification exercises, suggest that the non-Newtonian solver works as intended and it can be thus employed on more complex applications.
TL;DR: In this article , the friction factor with non-Newtonian fluids, especially in rough pipes, was calculated using validated three-dimensional Computational Fluid Dynamics models in Ansys CFX.
Abstract: The appropriate estimation of frictional losses in a pipeline system is essential. So far, little attention has been paid to determining the friction factors with non-Newtonian fluids, especially in rough pipes. This study aims at calculating the friction factor using validated three-dimensional Computational Fluid Dynamics models in Ansys CFX. Steady-state computations are performed with three different incompressible Herschel-Bulkley fluids in rough pipes with relative roughness of the inner pipe surface ε = 0.0005 – 0.01. A power-law type bath gel as a test fluid is used for experiments to validate our numerical model. The numerical results are compared with the measured values and also with numerous existing friction factor estimation models with the help of generalization of the Reynolds number in the relevant engineering range of Regen = 100 – 40,000. This paper shows that the existing approximations can not accurately describe the friction factor with pseudoplastic fluids in rough pipes. On the contrary, in the case of Bingham plastic fluid, a new, explicit calculation relation is found in a unified form accepted by the literature.
TL;DR: In this paper , the authors investigated the blood flow mechanism in an inclined artery with the unwanted growth inside the arterial wall by modeling blood as a non-Newtonian Casson fluid and found that slip velocity, inclination, yield stress, stenosis height and Reynolds number all have a considerable impact on flow characteristics during blood flow in the core region.
Abstract: In this study, the blood flow mechanism in an inclined artery with the unwanted growth inside the arterial wall has been investigated by modelling blood as a non-Newtonian Casson fluid. A significant quantitative investigation on various flow physical parameters, including axial velocity, volumetric flow rate, plug core radius, plug core velocity, wall shear stress, and effective viscosity, has been analyzed through numerical calculations under the assumption that blood flow is unsteady. According to this study, slip velocity, inclination, yield stress, stenosis height and Reynolds number all have made a considerable impact on flow characteristics during blood flow in the core region.
TL;DR: In this article , the authors analyzed the rheology of synovial fluid under the periodic filtration rate within the membrane and found that the pressure difference and transverse velocity are high when the periodic filter is cosine type whereas the shear stress on the wall is high for sine type of filter.
Abstract: This research measures the flow of synovial fluid through permeable membrane. It is assumed in this study that the ultrafiltration of blood plasma is a continuous function and repeatedly forms the action to keep synovial fluid normal in the joints. The novelty of this research is to analyze the rheology of synovial fluid under the periodic filtration rate within the membrane. To estimate the pressure and shear stress which are essential for the flow of synovial fluid between the synovial joints, mathematical modeling has been made for the synovial fluid flow through permeable membrane by the laws of mass and momentum and viscoelastic LPTT fluid model. The LPTT fluid has the viscoelastic effects in the presence of relaxation time, therefore for synovial fluid the present fluid model represents the best rheological properties. To find the analytical results for the rheology of the synovial fluid, a method proposed by Langlois is used. This research concludes that the pressure difference and transverse velocity are high when the periodic filtration is cosine type whereas the shear stress on the wall is high for sine type of filtration.