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The study of blood flow through stenotic arteries is more important as the existence and progression of stenosis may lead to severe damage. The current study aims to analyze and understand the non-Newtonian nature of blood flow through the multi-stenosed artery of an elliptical cross-section. The Carreau fluid model accounts for the non-Newtonian nature of blood. The mathematical equations are transformed to dimensionless form, and assumptions of mild stenosis are employed to reduce the non-linearity of the mathematical model. The perturbation method via polynomial technique is utilized to solve the resulting equations by considering W e 2 as the perturbation parameter. The results of the velocity and wall shear stress are examined graphically. It is found that stenosis severity substantially impacts flow velocity in the narrower portion of the artery. The stenosis growth strongly affects the flow velocity and wall shear stress in the stenotic region. The non-Newtonian effects are found to dominate along the minor axis. This fact assures that the conduit's narrower cross-section strengthens the fluid's non-Newtonian behavior. It is observed that the non-Newtonian fluid has a smaller velocity than the Newtonian fluid. Moreover, non-Newtonian fluid has a different nature along the minor and major axes, but Newtonian fluid has the same behavior. [ABSTRACT FROM AUTHOR]

• MHD non-Newtonian fluid flow with CNTs and heat transfer across a linearly shrinking sheet. • An exact solutions are extracted for the governing equations of the aforesaid flow. • Two types of non-Newtonian fluids like second grade fluid and Walters' liquid B. • The existence of unique and dual solutions domains are traced by physical parameters. • Dual solutions exist for second grade fluid for both slip and no-slip restrictions. The present paper focuses on electrically driven magnetohydrodynamic non-Newtonian fluid flow (viscoelastic fluid)with CNTs and heat transmission across a linearly shrinking sheet. The flow is urged with the partial slip conditions, radiation and heat source/sink. Single walled and multi walled CNTs are considered in this analysis. An exact solution is extracted for the governing equations of the aforesaid flow of two types of non-Newtonian fluids like second grade fluid and Walters' liquid B with CNTs using similarity transformations. The flow velocity is pretentious due to many physical parameters like magnetic force, visco-elasticity, slip parameter, whereas the energy profile is pretentious due to Prandtl number, Biot number, heat sink/source parameter and radiation parameter. The existence of unique and dual solutions domains are traced by combining the above parameters and velocity, energy profiles and skin friction are explained using graphs. The results reveal that the dual solutions exist for both types of viscoelastic fluids under specific flow restrictions. In particular, dual solutions exist for second grade fluid for both slip and no-slip restrictions. And similar observations are found for Walters' liquid B fluid for unique slip flow when viscoelastic parameter value increases above a definite value. Inclusion of magnetic field terminates the ambiguity of existence of solution for different λ 1 values for both viscoelastic fluids. [ABSTRACT FROM AUTHOR]

The theory of rheology of non-Newtonian fluids is based on the generalized Newtonian hypothesis of viscosity. The viscometers for non-Newtonian fluids should implement fluid flows with the known stress and strain state parameters distributions. Ideally, the distributions should be homogeneous in the flow domain. The idea of the proposed method is based on a combination of a capillary and a rotational viscometers implemented in the torus-shaped capillary viscometer. Analysis of the mathematical model of the inertial non-Newtonian fluid flow in the torus allowed to determine the conditions of homogeneity of the mechanical and thermal parameters in the flow domain and to develop method of viscosity measurement. The measured values are the shear rate on the inner surface of the capillary and the flow rate. The measurements are implemented with the computer vision system that processes data obtained from the high speed CMOS camera that records inertial flow in the transparent capillary illuminated with laser. The computer vision system is based on the application of deep convolutional neural network for laser speckle contrast imaging processing. During the experiments, the proposed viscometer was compared with the Brookfield rotational viscometer. The relative error of the proposed viscometer and method is less than 2 %. The inertial viscometer is compact, it allows to study the wide range of shear rates per one test in automatic mode, and it has low fluid capacity of approximately 1.87 ml. That makes it possible to use the viscometer as a point on care testing device in medicine to study the rheology of physiological fluids, in particular blood. [Display omitted] • Inertial flow in a torus-shape capillary is perfectly symmetrical and homogeneous. • Laser speckle-contrast imaging allows one to see flow velocity on an image. • Artificial intelligence allows computer vision to see shear rate of the fluid flow. • Inertial viscometer could be a novel point on care testing device in medicine. [ABSTRACT FROM AUTHOR]

We study the pressure driven transport of a multilayer system consisting of alternate Newtonian and non-Newtonian fluids in the narrow fluidic configuration. We consider the power law model to describe the rheology of the non-Newtonian fluid in this study. The first part of the analysis, employing the assumptions routinely conferred in the literature, constitutes for an analytical solution of the transport equation resulting in the closed-form expressions of velocity field and net throughput. We demonstrate that the rheology driven modification in the flow velocity for a given strength of the applied forcing leads to the prolific amplification in micro-pumping phenomena. In the second part, the use of artificial neural network (ANN) is implemented to present an alternative solution for the problem undertaken in this study by using the analytical results from the first part. To make the prediction using ANN, various influential transport parameters are considered and their effects on the velocity and net throughput are analyzed. It is elucidated that an appropriately trained neural network can act as a good alternative for time-consuming calculations on the multi-layered fluid flow in micro channels. The flow configuration considered in this analysis alongside the findings of our work may provide a pathway of developing novel analytical platforms for precise loading and handling of chemical samples of biological fluids in a portable fluidic environment. [Display omitted] • Transport of Multilayer system comprising of alternate Newtonian and non-Newtonian fluids. • Closed-form expressions of velocity field and net throughput. • The use of artificial neural network (ANN) implemented to present an alternative solution. • Trained neural network as a good alternative on the multi-layered fluid flow analysis. [ABSTRACT FROM AUTHOR]

The fracture network in fractured reservoirs is the main channel for fracturing fluid intrusion and gas flow, and the presence of liquid has a great influence on the gas flow pattern, and the gas flow shows more diversity in fluids with different properties such as fracturing fluid or formation water. In order to study the characteristics of gas-liquid two-phase flow in the microfracture network of the fractured gas reservoir, the topology of the microfracture network is simplified to T-junction and Y-junction. Based on the volume of fluid model, the gas-liquid two-phase flow interface is tracked. The model is solved by computational fluid dynamics software OpenFOAM, and the correctness of the model is verified by comparing it with laboratory microscopic experiment results. The flow characteristics of the gas phase in different fluids at the microscale and the influence of fluid parameters on flow pattern are analyzed. The results show that the properties of the liquid phase have a strong influence on the gas flow pattern, and the two-phase flow velocity and the properties of fluid parameters affect the gas flow to reach the stable state. The findings of this study can be used for reference to analyze the flow characteristics of gas in fracturing fluid and the flowback technology of fracturing gas well. • Numerical simulation for visualizing gas-liquid two-phase flow in micro-fracture using OpenFOAM. • Large and non-uniform bubbles in Newtonian fluids, small and uniform bubbles in non-Newtonian fluids. • Smaller the angle of gas-liquid velocity, the easier the two-phase flow to reach a stable state. • Increasing the wetting angle has little effect on the gas flow morphology at high velocity ratios. • Reduce the interfacial tension, the bubble deformation index becomes smaller, and the bubble edge presents an irregular shape. [ABSTRACT FROM AUTHOR]