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.

Drag Over A Fluid Sphere Filled With Couple Stress Due to Flow of A Couple Stress Fluid with Slip Condition

Abstract: In this article, the exact solution for a couple stress fluid flow past a fluid sphere filled with a couple stress fluid is considered using interfacial slip on the boundary. The velocity is expressed with regard to the stream function. The external velocity and internal velocity are alongside the drag coefficient. It was noticed that with the increases in slip parameter, the drag coefficient is decreasing and the inflow pattern has more circulations with more area appearing near the poles and internal flow disappears gradually. The special cases of viscous fluid, no-slip condition, and solid sphere are evaluated. A good understanding of the current and literature outcomes have been obtained, including the special case of a viscous fluid past a couple stress fluid sphere. HIGHLIGHTS The flow of couple stress fluid flow past a fluid sphere filled with couple stress fluid with slip over the surface is reported In case of no-slip condition, results are captured as s→∞. and also as μ→∞, fluid sphere can reduce to the case of a solid sphere For the case of viscous fluid can be recovered as a limiting case of the analysis by taking λ_e→∞, λ_i→∞, and χ_1→∞, χ_2→∞ GRAPHICAL ABSTRACT

The Existence and Dimension of the Attractor for a 3D Flow of a Non-Newtonian Fluid subject to Dynamic Boundary Conditions

Abstract: We consider non-Newtonian incompressible 3D fluid of Ladyzhenskaya type, in the setting of the dynamic boundary condition. Assuming sufficient growth rate of the stress tensor with respect to the velocity gradient, we establish explicit dimension estimate of the global attractor in terms of the physical parameters of the problem.

Slot Flow Approximation for Herschel-Bulkley Drilling Fluid through Eccentric Annuli

Abstract: The studies of fluid flow through eccentric annulus has been started since early 1940’s and numbers of solution in order to enhance the efficiency of the cutting transport to the surface have been developed. The solution developed so far by many investigators is either analytical or numerical and mostly involving parameters such as velocity distribution, shear stress, shear rates and pressure drop. The aim of this study is to develop and analyze the numerical solution of fluid flow through eccentric annuli which is represented by slot of variable height with the use of Herschel-Bulkley drilling fluid. Developed numerical solution is then used to estimate the Velocity distribution in the eccentric annuli as well as to determine flow rate for a given drilling condition. In addition, the rheology of non-Newtonian fluid (Bingham, Power and Herschel-Bulkley) will be discussed. By applying the correct assumption of eccentricity ratio (k=0.3) on the numerical solution developed earlier, velocity distribution were obtained. Apart from that, by representing the eccentric annuli as slot of variable height the accuracy of the solution obtained can be improved and no iterative computation needed.

Approximate Solutions of Differential Equations of Non-Newtonian Fluids Flow Arising in the Study of Helical Screw Rheometer

Abstract: The thesis presents the theoretical analyses of extrusion process inside Helical Screw Rheometer (HSR).Efforts to obtain better insight into the process must be mainly theoretical rather than experimental. But the hope, of course, is that better insight than experimental so gained will provide practical benefits such as better control of the processing, optimize the processing process and improve the quality of production. The main objective of the study is to develop mathematical models in order to evaluate the velocity profiles, shear stresses and volume flow rates for isothermal flow of incompressible non-Newtonian fluids in HSR.The calculations of these values are of great importance during the production process.In this thesis, two types of geometries are considered. ² In first geometry the Cartesian co-ordinates system is used to study the flow of third-grade fluid, co-rotational Maxwell fluid, Eyring fluid, Eyring-Powell fluid and Oldroyd 8-constant fluid models in HSR.The geometry of the HSR is simplified by unwrapping or flattening the channel, lands and the outside rotating barrel.A shallow infinite channel is considered by assuming the width of the channel large as compared to the depth.We also assumed that the screw surface, the lower plate, is stationary and the barrel surface, the upper plate, is moving across the top of the channel with a velocity at an angle to the direction of the channel.The phenomena is same as, the barrel held stationary and the screw rotates. Solutions for velocity profiles, volume flow rates, average velocity, shear and normal stresses, shear stresses at barrel surface and shear forces exerted on the fluid are obtained using analytical techniques.Adomian decomposition method is used to obtain the solutions for third-grade fluid, Eyring-Powell fluid and Oldroyd 8-constant fluid and perturbation method for co-rotational Maxwell fluid, where exact solution is obtained for Eyring fluid model.The effects of the rheological parameters, pressure gradients and flight angle on the velocity distributions are investigated and discussed.The behavior of the shear stresses is also discussed with the help of graphs for different values of non-Newtonian parameters. ² For better analysis cylindrical co-ordinates system is taken in second geometry, assuming that the outer barrel of radius r2 is stationary and the screw of radius r1 rotates with angular velocity W.Here we have used third-grade fluid model with and without flight angle and co-rotational Maxwell fluid model with nonzero flight angle in HSR.The analytical expressions for the velocities, shear and normal stresses and the shear stresses exerted by the fluid on the screw, volume flow rates and average velocity are derived using analytical techniques and the outcomes have been presented with the help of graphs.The effects of the rheological parameters and pressure gradients on the velocity distribution are investigated