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.

Solute dispersion in non-Newtonian fluids flow through small blood vessels: A varying viscosity approach

Abstract: Present work concerns the combined effect of Jeffrey fluid parameter and varying nature of viscosity on the solute dispersion in non-Newtonian fluids flow through small blood vessels. The generalized dispersion model of Sankarasubramanian and Gill (1973) has been considered. The objective of the present work is to understand the solute dispersion in non-Newtonian fluids flow through microvessels with absorbing walls under varying viscosity assumption. For more realistic modeling of blood flow in microvessels, Jeffrey and Herschel–Bulkley fluids model have been considered for a comparative study due to its low shear rate flow in small blood vessels such as arterioles, venules and capillaries. The whole solute dispersion analysis has been done for two alternative non-Newtonian fluids (Herschel–Bulkley and Jeffrey fluids) owing to their physiological importance. The present model has been validated by reducing it to previously studied specific cases of Newtonian, Bingham-plastic and Power-law fluids with constant/varying viscosities. It is perceived that the mean concentration, convection and axial dispersion coefficients are significantly affected by varying viscosity and Jeffrey fluid parameters. A noteworthy observation is that an increase in ratio of relaxation to retardation times (Jeffrey fluid parameter) enhanced the values of the transport coefficients. The outcome of the present study shows the diffusion of drugs to the physiological system through small blood vessels is significantly affected by the varying nature of viscosity and Jeffrey fluid parameters.

Experimental study on the special shear thinning process of a kind of non-Newtonian fluid

Abstract: To study the effect of long chain molecule and surface active agent on non-Newtonian fluid properties, rheological experiments on two different fluids have been done. The first group of the fluid is the hydroxyethyl cellulose water solution, and the second is the water solution containing the mixture of dodecyltriethyl ammonium bromide and lauryl sodium sulfate. With the increasing shear rate, shear thinning phenomenon appears in the first group of solution, and a special shear thickening-shear thinning phenomenon appears in the second group. It is considered that the special rheological phenomenon is caused by the difference between the aggregating and the departing speed of the colloidal particles formed in the fluid. The difference between the two speeds relates with the shear rate. The experiment results indicate that the rheological properties can be designed by choosing proper additives at a certain shear rate, and such a fluid with special viscosity variation should be included in the classification of the non-Newtonian fluid.

Study of blood viscosity at low shear rate and its flow through viscoelastic tubes and ducts

Abstract: A nonlinear mathematical model is developed analytically to study the flow characteristics of visco-elastic fluid through a visco-elastic pipe when it is subjected to external body acceleration. The equations governing the motion of the system are solved analytically with the use of appropriate boundary conditions. For the present scope of study the flow of visco-elastic fluid (blood) in smaller artery which is visco-elastic in nature has been taken. The artery is assumed to be a flexible cylindrical tube containing a non-Newtonian fluid. The unsteady flow mechanism in the artery is subjected to a pulsatile pressure gradient arising from the normal functioning of the heart and also the external body acceleration. Numerical models have finally been developed for Newtonian and Non-Newtonian fluid in order to have a thorough quantitative measure of the effects of body acceleration on the flow velocity, volume flow rate and the wall shear stress of blood in normal human artery and when the artery gets stiffer, just to validate the applicability of the present mathematical model.

Conjugated heat transfer in the flow of a non-Newtonian fluid with variable properties in a flat duct

Abstract: We solve the problem of the flow of a nonlinearly viscoelastic fluid in the presence of large pressure drops and appreciable nonisothermicity.

Laminar Entry Flow of Herschel-Bulkley Fluids in a Circular Pipe

Abstract: Fargie and Martin used an elegant approach to obtain the entry region flow of Newtonian fluids in a circular pipe. They combined the differential and integral momentum equation in such a way that elimination of pressure gradient leads to a closed form solution. In this paper we extend this procedure to study the laminar entry region flow of Herschel-Bulkley fluids in a circular pipe. The solution procedure involves certain approximations. Applicability of these approximations to Herschel-Bulkley fluids has been discussed and the flow description has been obtained for various values of the flow behavior index and the Herschel-Bulkley number. Results have been illustrated graphically and compared with other available solutions: momentum integral and momentum energy integral solutions of the problem. Data displayed in the paper should be useful for design of any flow intake device involving Herschel-Bulkley fluids.