Influence of Finite Number of Chain Segments, Hydrodynamic Interaction, and Internal Viscosity on Intrinsic Birefringence and Viscosity of Polymer Solutions in an Oscillating Laminar Flow Field

1967 ◽  
Vol 46 (12) ◽  
pp. 4881-4885 ◽  
Author(s):  
G. B. Thurston ◽  
A. Peterlin
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Finite Number ◽  
Hydrodynamic Interaction ◽  
Polymer Solutions ◽  
Internal Viscosity ◽  
Intrinsic Birefringence

Heat Transfer in Internal Flows of Non-Linear Fluids: A Review

2006 ◽  
Author(s):  
Dennis A. Siginer ◽  
Mario F. Letelier
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Heat Transfer Enhancement ◽  
Polymer Solutions ◽  
Single Mode ◽  
Secondary Flows ◽  
Transfer Enhancement ◽  
Experimental Heat ◽  
Aqueous Polymer ◽  
Non Linear

A survey of the developments in heat transfer studies of non-linear inelastic as well as elastic fluids in tubes is given. Experimental findings concerning heat transfer enhancement characteristics of viscoelastic aqueous polymer solutions are very significant. Specifically, it is reported that heat transfer results for viscoelastic aqueous polymer solutions are drastically higher than those found for water in laminar flow in rectangular ducts. A number of investigators suggested that the high experimental heat transfer values were due to secondary flows resulting from the elasticity of the fluids. In this context recent results concerning the fully developed thermal field in constant pressure gradient driven laminar flow of a class of viscoelastic fluids characterized by single mode, non-affine constitutive equations in straight pipes of arbitrary contour ∂D is reviewed. Heat transfer enhancement due to shear-thinning is identified together with the enhancement due to the inherent elasticity of the fluid. The latter is the result of secondary flows in the cross-section. Increasingly large enhancements are computed with increasing elasticity of the fluid as compared to its Newtonian counterpart. Large enhancements are possible even with dilute fluids. Isotherms for the temperature field are presented and discussed for several non-circular contours such as the ellipse and the equilateral triangle together with heat transfer behavior in terms of the Nusselt number Nu.

Drag Reduction of Polymer Solutions in a Pipe With a Highly Water-Repellent Wall

1999 ◽  
Author(s):  
Keizo Watanabe ◽  
Hiroshi Udagawa
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Drag Reduction ◽  
Polymer Solutions ◽  
Tap Water ◽  
Acrylic Resin ◽  
Water Repellent ◽  
Number Range ◽  
Surfactant Solutions ◽  
Laminar And Turbulent Flow

Abstract By applying a highly water-repellent wall pipe in the drag reduction of polymer solutions, a flow system in which drag reduction is obtained in both laminar and turbulent flow ranges has been realized. Experiments were carried out to measure the pressure drop in pipes with a highly water-repellent wall and an acrylic resin wall by means of a pressure transducer. The diameter of the pipe was 6mm. The polymer solutions tested were PE015 aqueous solutions in the concentration range of 30ppm∼1000ppm. The drag reduction ratio for laminar flow was about 11∼15%. To understand this effect, the pressure drop was measured by using surfactant solutions and degassed water, and by pressurizing tap water in the pipeline. It was shown that the laminar drag reduction does not occur in the case of surfactant solutions although degassed water and pressurizing tap water in the pipeline have no effect on the reduction. In the laminar flow range, the friction factor of a power-law fluid with fluid slip was analyzed by applying the modified boundary condition on fluid slip at the pipe wall, and the analytical results agree with the experimental results in the low Reynolds number range.

Investigation on Laminar Flow Field Performances in a Dual-Impeller Stirred Tank

2012 ◽  
Vol 550-553 ◽  
pp. 2964-2967
Author(s):  
De Yu Luan ◽  
Shen Jie Zhou ◽  
Song Ying Chen
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Velocity Distribution ◽  
Radial Velocity ◽  
Velocity Vector ◽  
Equations Of Motion ◽  
Stirred Tank ◽  
Field Pattern ◽  
3D Flow ◽  
Multiple Reference

Abstract: The 3D flow field generated by a dual-impeller in the agitation of glycerin fluid was simulated using the commercial CFD package. The flow was modeled as laminar and a multiple reference frame (MRF) approach was used to solve the discretized equations of motion. The velocity profiles with a dual-impeller rotating at constant speed of 200r/min and at different layer clearances were obtained. By analysis to their axial and radial velocity vector plots and velocity distribution curves, it is found that the velocity distributions of the dual 6-bladed radial disc turbines (2-6DT) are better when the clearance is bigger or equal to the T/2, accompanied with the flow field pattern of parallel flow. Moreover，when the clearance is smaller or equal to the T/3, there are more advantages for 6-bladed radial disc turbines + pitch 4-bladed turbines (6DT+PTB) than other combinations，followed by the flow field pattern of connected flow.

Effects of System Rotation on Disturbances Injected Into Laminar Flow

2015 ◽  
Author(s):  
Oaki Iida ◽  
Yosuke Aono
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Turbulent Flow ◽  
Turbulent Diffusion ◽  
Body Force ◽  
The Body ◽  
Rotational Axis ◽  
System Rotation ◽  
Inhomogeneous Flow ◽  
Turbulent Flow Field

Effects of system rotation are investigated on inhomogeneous flow where disturbances are transported from turbulent to non-turbulent flow field through advection and turbulent diffusion. With the body force on the fringe region, spectral method is used for inhomogeneous flow which is stirred at the bottom of the cuboid computational box. As a result, it is found that inertial waves with a constant helicity are transmitted in the direction perpendicular to the stirred surface, and parallel to rotational axis. In this study, the effects of system rotation on generation and propagation of wave are discussed.

Sign in / Sign up

Export Citation Format

Share Document