Turbulent structures of nonnewtonian solutions containing. The model predicts turbulent non newtonian flows, provided rheology data is available. Transitional and turbulent flow of nonnewtonian slurries in pipes paul thomas slatter department of civil engineering, university of cape town, private bag, rondebosch 7700, republic of south africa. To discuss the various aspects of research in the non newtonian fluid mechanics field. The results reported herein span the laminar, transition and turbulent flow. Further 2, the radial distribution of velocity averaged over regions large compared with the eddy dimensions departs markedly from the parabolic distribution which would be expected for a newtonian fluid. Hello, i use fluent and need to simulate polymer viscosity vs shear rate and the turbulence.
This fact further suggests that the turbulent newtonian liquid may, for certain purposes, be regarded as a nonnewtonian fluid. Cfd study of the turbulent forced convective heat transfer of nonnewtonian nanofluid 94 iranian journal of chemical engineering, vol. In order to maintain a constant speed, a shear stress. First select turbulence modelling select the model that you want to use in models. These equations are consistent with those used for newtonian fluids and previous work on the behavior of generalized nonnewtonian fluids. These models are compared with three previously published models for laminar flow and five previously published models for turbulent flow using a recently extended experimental database for non. Cfd study of the turbulent forced convective heat transfer of. The polymer concentration is varied from 75, 100, and 125 ppm to reach the point of maximum.
The turbulent flow of nonnewtonian fluids in the absence of. On the basis of the theory for the flow of non newtonian fluids described above, we can derive the existence of other phenomena. Pdf turbulent flow of nonnewtonian fluids in a partially blocked. A study of the nonnewtonian turbulent fluid flow through an. Problems involving nonnewtonian fluids, proceedings of the third international conference on numerical methods in laminar and turbulent flow, august 811, 1983, university of washington, seattle, pp. Turbulence and viscosity of nonnewtonian fluids cfd.
The exact mechanism still proves somewhat elusive, even for newtonian fluids. A general correlation for turbulent friction factors in non. Largeeddy simulation of turbulent pipe flow of powerlaw fluids. While some foods can be classified as ideal solids hookes law or ideal fluids newtonian, most behave as nonnewtonian fluids or even exhibit viscoelastic behavior, i. The turbulent structure of a channel flow of xanthan gum xg polymer solution is experimentally investigated and compared with water flow at a reynolds number of re 7200 based on channel height and properties of water and re. Pullum2 1department of mechanical and aerospace engineering monash university, clayton, vic 3800, australia.
Cfd study of the turbulent forced convective heat transfer of non newtonian nanofluid 94 iranian journal of chemical engineering, vol. Application of sonarbased, clampon flow meter in oilsand. On the basis of the theory for the flow of nonnewtonian fluids described above, we can derive the existence of other phenomena. This fact further suggests that the turbulent newtonian liquid may, for certain purposes, be regarded as a non newtonian fluid. In the general case, the flow curve, a plot of shear stress against shear rate, is not linear. Turbulent transport near the wall in newtonian and non. Thermal and hydrodynamic performances of turbulent flow in the annular tube were investigated for different concentrations of the nonnewtonian nanofluid. Determining the viscous behavior of nonnewtonian fluids in a. A general correlation for turbulent friction factors in. For nonnewtonian fluids some experimental work exists for the viscoelastic case but none is available for timeindependent nonnewtonian fluids.
Friction losses of newtonian and nonnewtonian fluids. Nonnewtonian flow in the process industries fundamentals and engineering applications r. Proceedings of the 4th international conference of fluid flow, heat and mass transfer ffhmt17 toronto, canada august 21 23, 2017 paper no. Nonnewtonian fluid mechanics is a field of study which is growing in prominence and importance as the years progress, not least because many of the fluids one encounters in everyday life are nonnewtonian in their behavior. Turbulence, simulation and dynamics book pdf by donald matos, cristian valerio fluid mechanics is the study of how fluids move and the forces that develop as a result. In the present study, laminar transient nonnewtonian pipe flow is simulated using the power and cross models. Laminarturbulent transition in pipe flow for newtonian. Rheology is the study of how fluids flow and solids deform when subjected to forces. Apr 04, 2015 new models for the prediction of laminar and turbulent flow of non newtonian fluids in open channels of different crosssectional shapes are proposed. Chhabra abstract the objective of this chapter is to introduce and to illustrate the frequent and wide occurrence of nonnewtonian. Cfd analysis of newtonian turbulent flows in annular spaces. Several formulae have been proposed for treating nonnewtonian pipe flow friction data, and with one exception they rely in some way on laminar data for predicting turbulent data. Comparison of methods for predicting head loss in turbulent pipe flow of non newtonian fluids article pdf available in transactions of the institute of measurement and control 61.
Laminar and turbulent flow of nonnewtonian fluids in open. Many salt solutions and molten polymers are nonnewtonian fluids, as are many. Transitional and turbulent flow of nonnewtonian slurries in. A nonnewtonian fluid is a fluid that does not follow newtons law of viscosity, i. For infrastructure master program engineering facultyiug. Curvature effects of fluid flow through 180 degree channel proceedings of fifth. There can be two types of friction assumptions in nonnewtonian fluids.
The flow is characterized by using the continuum approach. Applications are involved with highly nonnewtonian wood fiber and paper pulp suspensions in laminar and turbulent flows. Dietmann, rheooptical investigations and nearwall turbulence structure of polymer solutions in turbulent channel flow, j. New models for the prediction of laminar and turbulent flow of nonnewtonian fluids in open channels of different crosssectional shapes are proposed. It collapses adequately the data measured in laminar flow and turbulent flow into a single flow curve and gives the basis for the design of turbulent flow viscometers. All correlations presented are expressed in a simple and convenient form by separating the contribution of curvature effects of the reel and friction pressure losses in. The instantaneous wall viscosity in pipe flow of power law fluids. Interaction of nonnewtonian fluid dynamics and turbulence. The turbulent flows of non newtonian fluids are of importance in mechanical and. Investigation of nonnewtonian fluid effects during transient. A model of averaged molecular viscosity for turbulent flow of non. Laminar flows occur at low values of the reynolds number, which is defined as the product of representative scales of velocity and length divided by the kinematic viscosity. Perhaps the most widely accepted and quoted of these formulae is that due tododge andmetzner 2 which is also stated to be rigorous. The only reliable approach open to designers of pipeline systems conveyin,g nonnewtonian slurries in.
Pdf new models for the prediction of laminar and turbulent flow of nonnewtonian fluids in open channels of different crosssectional shapes. One of the first studies that were made of nonnewtonian flow was conducted by chhabra and richardson 3 in which they develop a flow pattern based in a newtonian one. Pdf comparison of methods for predicting head loss in. Experimental assessment of turbulence convective heat. For this type of flow, you can use the carreau viscosity model. They are based on an empirical estimate of the shift in the wall layer edge and the kolmogorov point. The problem under consideration here is the axial turbulent flow of nonnew. For newtonian fluids, such as water and oil, the location of the transition is well established and the calculation is trivial. To this aim, the quasi2d equations of water hammer for nonnewtonian fluids are. This thesis addresses this design problem, with particular emphasis on the theoretical modelling of the laminar turbulent transition and turbulent flow behaviour of these slurries in pipes. Friction factors for turbulent flow of nonnewtonian. Some consideration is given to thedodgemetzner equation which seems to. For newtonian fluids, the engineering predictions for pressure drop in turbulent pipe flow are well established.
Plane flow model of nonnewtonian turbulent stratified flow. Some consideration is given to thedodgemetzner equation which seems to show that. This is an attractive feature of the model as no general nonnewtonian flow correlations are available in the literature. Nonnewtonian flow and convective heat transfer characteristics were experimentally investigated through an annular tube. Direct numerical simulation of the weakly turbulent flow of nonnewtonian fluids with shearthinning rheology are undertaken. Reviewing these works, it is straightforward that there is a limited knowledge concerning the friction factor for nonnewtonian. Turbulence, timeindependent nonnewtonian, power law, pipe flow, wall layer 1. Smooth velocity profiles ensured at the corners to avoid. Logarithmic correlations for turbulent pipe flow of power law fluids. Pressure loss equations for laminar and turbulent non. Non newtonian fluid mechanics is a field of study which is growing in prominence and importance as the years progress, not least because many of the fluids one encounters in everyday life are non newtonian in their behavior. Ketchup, for example, becomes runnier when shaken and is thus a nonnewtonian fluid.
Newtonian fluids on different parameters on spiral. Laminarturbulent transition flows of nonnewtonian slurries. The relation between the flow of nonnewtonian fluids and. In non newtonian fluids, viscosity can change when under force to either more liquid or more solid. The flow in pipe is uniform, which interfacial liquid level and waves causing vortex motion and energy dissipation are not concerned. The goal of the study is to examine the possibilities of using non. This paper presents a coherent set of equations for the laminar and turbulent flow of herschelbulkley fluids. To confirm the theoretical analysis, experimental data were taken on both polymeric gels and solid. Numerical analysis of a nonnewtonian fluid in agitated. For nonnewtonian fluids there are many different approaches but no guidelines as to. It is well known 1 that if a newtonian fluid such as water flows through a tube of circular crosssection under conditions for which the critical reynolds number is exceeded, the relation between pressure gradient and volume rate of flow is non linear.
Interaction of nonnewtonian fluid dynamics and turbulence on. Transitional and turbulent flow of nonnewtonian slurries. Richardson department of chemical and biological process engineering university of wales, swansea swansea sa2 8pp great britain. Flow simulation is capable of predicting both laminar and turbulent flows. Correlations of friction factors are presented for the general case of purely viscous non newtonian fluids without requiring a priori the adoption of a rheological model. Submissions in all areas of flowing complex fluids are welcomed, including polymer melts and solutions, suspensions, colloids, surfactant solutions, biological fluids, gels, liquid crystals and granular materials. A useful tool to study and evaluate the hydrodynamics of twophase air non newtonian fluid flow is computational fluid dynamics cfd. The flow of non newtonian fluids through an annulus is important in many industrial fields such as oil well drilling, extruding plas tics, parallel tube heat exchanger, etc. Turbulent flow of nonnewtonian fluids in a partially blocked pipe. The objective of this study, a parametric simulation, was performed to investigate the considerable influence of non.
This thesis addresses this design problem, with particular emphasis on the theoretical modelling of the laminarturbulent transition and turbulent flow behaviour of these slurries in pipes. Heat transfer with nonnewtonian fluids is a vast topic given the wide range of fluids and flows of interest, and it cannot be covered in its vastness in this chapter. Friction losses of newtonian and nonnewtonian fluids flowing. Introduction all turbulent non newtonian turbulent transport phenomena have been studied using rheological parameters determined separately with rheometers operating in laminar flow. The suggested approach is based on the similarity of nonnewtonian turbulent flow behaviour with that of newtonian one.
The wall shear rate in nonnewtonian turbulent pipe flow. Pdf fine particle suspensions often form nonnewtonian slurries. Governing equations in this study, the single phase model for numerical investigation of two dimensional symmetric steady, forced turbulence convection flow of nanofluid inside a. Pdf turbulent flow of nonnewtonian fluids in a partially. Newtonian fluids are considered to those types of fluids that do not follow newtons law of viscosity where viscosity would change in either more solid or liquid. As shown, the timeaveraged axial velocity for a turbulent pipe flow velocity profile is a function of radial position, from zero at the wall to a maximum at the centerline of the pipe. Pullum2 1department of mechanical and aerospace engineering monash university, clayton, vic.
Investigation of nonnewtonian fluid effects during. Velocity profiles, viscosity data, and laminar flow friction factor equations for flow in a circular duct imece2008 cfd and experimental studies of yield powerlaw fluids in turbulent pipe flow. In addition, the analysis has permitted the prediction of non. The flow near the wall is characterized by steep velocity gradients and. The correlation of nonnewtonian turbulent pipeflow data. Ii newtonian and non newtonian flow ibarz, albert, castellperez, elena, barbosa canovas, gustavo v. Ive try with some turbulent models but they want constant viscosity to calculate the turbulence.
Heat transfer with non newtonian fluids is a vast topic given the wide range of fluids. Velocity profiles, viscosity data, and laminar flow friction factor equations for flow in a circular duct conference paper pdf available january 2008 with. The hydraulics of sludge pumping is highly dependent on the concentration and properties of the solids in the sludge. When the reynolds number exceeds a certain critical value, the flow becomes turbulent, i. The sludge flow is classified into laminar flow or turbulent flow. These results suggest that some analogy may exist between the turbulent newtonian fluid and the laminar flow of a nonnewtonian fluid. Turbulence, timeindependent non newtonian, power law, pipe flow, wall layer 1. One of the first studies that were made of non newtonian flow was conducted by chhabra and richardson 3 in which they develop a flow pattern based in a newtonian one. To this aim, the quasi2d equations of water hammer for non newtonian fluids are. Fluid mechanics and pipe flow turbulence, simulation and. Nonnewtonian fluid flows in pipes and annular channels are. Turbulent flow of nonnewtonian fluids in a partially blocked.
Encyclopedia of life support systems eolss where x is displacement and t is time. Turbulent flow of nonnewtonian fluids in ansys fluent. Is it possible to copy the non newtonian model in a udf and then use a turbulent model. Several formulae have been proposed for treating non newtonian pipe flow friction data, and with one exception they rely in some way on laminar data for predicting turbulent data. These equations are consistent with those used for newtonian fluids and previous work on the behavior of generalized non newtonian fluids. Pdf laminar and turbulent flow of nonnewtonian fluids in. However, in the case of nonnewtonian liquids, only a few design techniques have been proposed and these do not share a common basis with the approach for newtonian systems. The twophase flow is made up of two kinds of non newtonian fluid. It has been noted see, for example, 1 that in turbulent flow of a newtonian fluid in a straight pipe with circular crosssection, under a constant pressure gradient, the rate of discharge is.
The only reliable approach open to designers of pipeline systems conveying nonnewtonian slurries in the turbulent flow regime has been large scalepipetests. The method greatly simplifies the analysis of turbulent transport phenomena in nonnewtonian fluids. Introduction all turbulent nonnewtonian turbulent transport phenomena have been studied using rheological parameters determined separately with rheometers operating in laminar flow. For non newtonian fluids some experimental work exists for the viscoelastic case but none is available for timeindependent non newtonian fluids. The twophase flow is made up of two kinds of nonnewtonian fluid. The main cause of classifying sludge as a nonnewtonian fluid is the presence of solids in the range of 1% and above. Fluids include liquids and gases and fluid flow can be either laminar or turbulent. Newtonian turbulent velocity profiles, a topic on which the published literature is entirely silent. This model example illustrates applications of this type that would nominally be built using. They proposed a new approach to estimate energy dissipation and pressure decay 22 and 23. This is an attractive feature of the model as no general non newtonian flow correlations are available in the literature. The applicability of newtonian friction factor correlations for predicting friction pressure losses in turbulent coiled tubing ct flow of nonnewtonian fluids is investigated. The same cannot be said for nonnewtonian flows, which have a higher degree of complexity. Nonnewtonian fluid from newtonian velocity profiles after y 15 has been reported due to the drag reducing effects associated with shear thinning properties of nonnewtonian fluid.
The turbulent flows of nonnewtonian fluids are of importance in mechanical and. The laminarturbulent transition is an extremely important piece of information for the pipe system designer because at this point the behaviour of the fluid changes fundamentally. In the present study, laminar transient non newtonian pipe flow is simulated using the power and cross models. Cfd simulations of twophase gasnonnewtonian fluid flows in. Applications are involved with highly non newtonian wood fiber and paper pulp suspensions in laminar and turbulent flows. The turbulent flow of nonnewtonian fluids in the absence. Onedimensional model of turbulent flow of nonnewtonian drilling. A generic model for calculation of frictional losses in pipe. Chhabra department of chemical engineering indian institute of technology kanpur 208 016 india and j. In nonnewtonian fluids, viscosity can change when under force to either more liquid or more solid.
Cfd study of the turbulent forced convective heat transfer. The same cannot be said for non newtonian flows, which have a higher degree of complexity. Pdf new models for the prediction of laminar and turbulent flow of non newtonian fluids in open channels of different crosssectional shapes. The method greatly simplifies the analysis of turbulent transport phenomena in non newtonian fluids. A non newtonian fluid is a fluid that does not follow newtons law of viscosity, i. Plane flow model of nonnewtonian turbulent stratified. A study of the nonnewtonian turbulent fluid flow through. Turbulent flow of nonnewtonian systems dodge 1959 aiche. Laminarturbulent transition in pipe flow for newtonian and. Turbulent flow of nonnewtonian fluids in a partially. A useful tool to study and evaluate the hydrodynamics of twophase airnonnewtonian fluid flow is computational fluid dynamics cfd. The model predicts turbulent nonnewtonian flows, provided rheology data is available. Turbulent pipe flow of nonnewtonian fluids springerlink.
The aim of study in this paper is to find a theoretical approach that could match the experimentally investigated turbulent flow behavior of nonnewtonian slurries flowing in pipes. And the flow patterns concerned in this paper are turbulent flow. This model shows the influence of shear rate dependent viscosity on the flow of a linear polystyrene solution. The only reliable approach open to designers of pipeline systems conveyin,g non newtonian slurries in. This paper presents a method for calculating the wall shear rate in pipe turbulent flow. The influence of sheardependent rheology on turbulent pipe flow. A generic model for calculation of frictional losses in. To discuss the various aspects of research in the nonnewtonian fluid mechanics field.
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