Transport to a Rotating Disk in Turbulent Flow at High Prandtl or Schmidt Number

1973 ◽  
Vol 95 (4) ◽  
pp. 566-568 ◽  
Author(s):  
J. A. Paterson ◽  
R. Greif
Keyword(s):  
Experimental Data ◽  
Turbulent Flow ◽  
Mass Flux ◽  
Eddy Viscosity ◽  
Schmidt Number ◽  
Rotating Disk ◽  
Conservation Equations ◽  
High Schmidt Number ◽  
Number Problem ◽  
Good Agreement

The eddy viscosity distribution near the surface of a rotating disk is determined from an analysis of the basic conservation equations. The results are applied to the high Schmidt number problem and good agreement is obtained with experimental data for the mass flux.

scholarly journals Direct Numerical Simulation of separated turbulent flow in axisymmetric diffuser

2021 ◽  
Vol 2103 (1) ◽  
pp. 012214
Author(s):  
A S Stabnikov ◽  
D K Kolmogorov ◽  
A V Garbaruk ◽  
F R Menter
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Turbulent Flow ◽  
Turbulence Model ◽  
Eddy Viscosity ◽  
Separated Flow ◽  
Model Improvement ◽  
Good Agreement

Abstract Direct numerical simulation (DNS) of the separated flow in axisymmetric CS0 diffuser is conducted. The obtained results are in a good agreement with experimental data of Driver and substantially supplement them. Along with other data, eddy viscosity extracted from performed DNS could be used for RANS turbulence model improvement.

Prediction of Cavitation Inception Within Regions of Flow Separation

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Turbulent Flow ◽  
Flow Separation ◽  
Computational Method ◽  
Average Flow ◽  
Cavitation Inception ◽  
The Core ◽  
Good Agreement

Cavitation within regions of flow separation appears in drifting vortices. A two-part computational method is employed for prediction of cavitation inception number there. The first part is an analysis of the average flow in separation regions without consideration of an impact of vortices. The second part is an analysis of equilibrium of the bubble within the core of a vortex located in the turbulent flow of known average characteristics. Computed cavitation inception numbers for axisymmetric flows are in the good agreement with the known experimental data.

On the Friction Reducing Non-Newtonian Flow Around an Enclosed Disk

1974 ◽  
Vol 41 (1) ◽  
pp. 45-50 ◽  
Author(s):  
E. Bilgen ◽  
P. Vasseur
Keyword(s):  
Theoretical Analysis ◽  
Turbulent Flow ◽  
Boundary Layers ◽  
Flow Characteristics ◽  
Rotating Disk ◽  
Newtonian Flow ◽  
Dilute Polymer Solutions ◽  
Theoretical Predictions ◽  
Minimum Resistance ◽  
Good Agreement

The turbulent flow characteristics of non-Newtonian dilute polymer solutions around an enclosed rotating disk have been studied both theoretically and experimentally. In the theoretical analysis, the momentum equations of the boundary layers on both rotating disk and housing have been solved numerically using appropriate velocity profiles. It is shown that the theoretical predictions for minimum resistance conditions are in good agreement with the experimental results of this study and with those in the literature.

The Experimental Study and Numerical Simulation of Turbulent Flow in Pumping Forebay

2009 ◽  
Author(s):  
Chao Liu ◽  
Jiren Zhou ◽  
Li Cheng
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Turbulent Flow ◽  
Three Dimensional ◽  
Computational Results ◽  
Experiment Study ◽  
Study Results ◽  
Measurement Results ◽  
Good Agreement ◽  
Made In

The experiment study was made to optimize the design of a pumping forebay. The Combined-sills were made in the forebay to eliminate the circulation and vortices of the diffusing flow successfully. The Numerical simulation of three-dimensional turbulent flow is applied on the complicate fore-and-aft flow of sills. The computational results are compared with the measurement results of physical model. The calculated results are in good agreement with the experimental data. The flow pattern is obviously improved. The study results have been applied in the project which gives a uniform approach flow to the pumping sump.

scholarly journals Numerical Study of Turbulent Secondary Flows in Curved Ducts

1990 ◽  
Vol 112 (2) ◽  
pp. 205-211 ◽  
Author(s):  
N. Hur ◽  
S. Thangam ◽  
C. G. Speziale
Keyword(s):  
Experimental Data ◽  
Turbulent Flow ◽  
Secondary Flow ◽  
Cross Section ◽  
Numerical Study ◽  
Secondary Flows ◽  
Fully Developed Turbulent Flow ◽  
Volume Method ◽  
Curved Ducts ◽  
Good Agreement

The pressure driven, fully developed turbulent flow of an incompressible viscous fluid in curved ducts of square cross-section is studied numerically by making use of a finite volume method. A nonlinear K -1 model is used to represent the turbulence. The results for both straight and curved ducts are presented. For the case of fully developed turbulent flow in straight ducts, the secondary flow is characterized by an eight-vortex structure for which the computed flowfield is shown to be in good agreement with available experimental data. The introduction of moderate curvature is shown to cause a substantial increase in the strength of the secondary flow and to change the secondary flow pattern to either a double-vortex or a four-vortex configuration.

scholarly journals A Momentum Integral Method to Predict the Frictional Torque of a Rotating Disk With Protruding Bolts

1998 ◽  
Author(s):  
W. Gärtner
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Integral Equations ◽  
Critical Review ◽  
Integral Method ◽  
Rotating Disk ◽  
Frictional Torque ◽  
Momentum Integral ◽  
Good Agreement

A momentum integral method was developed to predict the frictional torque of a disk rotating in quiescent air with cylindrical protrusions mounted on its surface. The predicted torque is compared to experimental data taken for the protrusions placed on two different radii on the disk with two different numbers of protrusions on each radius. A critical review of the calculated results reveals that caused by the protrusions the predicted thickness of the boundary layer on the disk is of the same magnitude as the radius of the disk. Since in this case Prandtl’s simplifications for the boundary layer on which the momentum integral equations are based upon are not valid their use appears to be doubtful. However, the predicted frictional torque is in good agreement with the measurements for all configurations tested except for that with the smallest circumferential distance between the protrusions where the torque is overpredicted by the method. The application of the method for a disk rotating in a stationary housing is briefly discussed.

Mach Number Scaling of Single-Component, Two-Phase Flow

1993 ◽  
Vol 115 (4) ◽  
pp. 772-777
Author(s):  
D. E. Nikitopoulos
Keyword(s):  
Experimental Data ◽  
Mach Number ◽  
Mass Flux ◽  
Two Phase Flow ◽  
Critical Mass ◽  
Critical Flow ◽  
Phase Flow ◽  
Homogeneous State ◽  
Two Phase ◽  
Good Agreement

A simple two-fluid formulation is used to investigate compressibility effects and Mach number scaling for equilibrium, evaporating two-phase flow. The definition of the local two-phase Mach number emerges from a critical flow analysis. Comparisons of the theoretical critical mass flux with existing experimental data obtained in steam-water flows show very good agreement for moderate and high qualities over a wide critical pressure range. Within this quality range the predicted critical mass flux is quite insensitive to the velocity ratio. The analysis confirms previous observations, based on homogeneous flow models, indicating that in variable area ducts the critical state does not occur at a geometrical throat. Results of existing critical flow experiments in slowly diverging ducts are discussed in the light of this conclusion. A way from the neighborhood of the flash horizon, pressure-drop and kinetic energy changes are shown to scale with similar local Mach functions as those of single-phase compressible flow. Existing experimental data from vertical-upwards and horizontal two-phase flows in pipes indicate that the Mach number calculated on the basis of the local homogeneous state provides the optimum scaling performance. Scaling of the same experimental data using a Mach number based on the local nonhomogeneous state provides results that are in reasonably good agreement with the theoretical scaling guidelines and predictions, but is handicapped by considerable scatter in the scaled experimental variables.

Single-Phase Heat Transfer and Fluid Flow in Micropipes

2003 ◽  
Author(s):  
Gian Piero Celata
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Reynolds Number ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Transfer Rate ◽  
Single Phase ◽  
Flow Transition ◽  
Laminar And Turbulent Regimes ◽  
Good Agreement

The objective of the present paper is to provide a general overview of the research carried out so far in single-phase heat transfer and flow in capillary (micro) pipes. Laminar flow and laminar-to-turbulent flow transition are analyzed in detail in order to clarify the discrepancies among the results obtained by different researchers. Experiments performed in the ENEA laboratory indicate that in laminar flow regime the friction factor is in good agreement with the Hagen-Poiseuille theory for Reynolds number below 600–800. For higher values of Reynolds number, experimental data depart from the Hagen-Poiseuille law to the side of higher f values. The transition from laminar-to-turbulent flow occurs for Reynolds number in the range 1800–2500. Heat transfer experiments show that heat transfer correlations in laminar and turbulent regimes, developed for conventional (macro) tubes, are not properly adequate for heat transfer rate prediction in microtubes.

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