Numerical Simulation and Experimental Study of Particle Dynamics in a Rotating Drum with Flights

2017 ◽  
Vol 899 ◽  
pp. 65-70 ◽  
Author(s):  
Suellen Mendonça Nascimento ◽  
F.P. de Lima ◽  
Claudio Roberto Duarte ◽  
Marcos Antonio de Souza Barrozo
Keyword(s):  
Experimental Data ◽  
Granular Flow ◽  
Numerical Study ◽  
Operating Conditions ◽  
Particle Dynamic ◽  
Multiphase Model ◽  
Theoretical Studies ◽  
Rotating Drum ◽  
Dynamics Of Particles ◽  
Good Agreement

Rotary dryers are widely used in various industries. Although numerous research efforts have focused on characterizing the dynamics of these equipments, the design of rotating dryers is complex, and theoretical studies are necessary to gain an in-depth understanding of the dynamics of particles in these dryers. This paper aims to investigate the particle dynamic behavior in a rotating drum with flights, based on CFD and experimental results. In the numerical study it was used the Eulerian-Eulerian multiphase model along with the kinetic theory of granular flow. The holdups of solids in the flights were compared with experimental data, using a methodology created specifically for this purpose. The simulated results were in good agreement with the experimental data and the present work has shown that the Eulerian approach has been able to predict the fluid dynamics behavior in different operating conditions.

An Investigation of the Different Flow Regimes in a Rotating Drum through Experimental and Simulation

2014 ◽  
Vol 802 ◽  
pp. 215-219
Author(s):  
D.A. Santos ◽  
Irineu Petri Jr. ◽  
C.R. Duarte ◽  
M.A.S. Barrozo
Keyword(s):  
Experimental Data ◽  
Particle Velocity ◽  
High Speed ◽  
Video Camera ◽  
Particle Dynamic ◽  
Multiphase Model ◽  
Rotating Drum ◽  
High Speed Video Camera ◽  
Simulation Results ◽  
Good Agreement

This paper aims to investigate the particle dynamic behavior in a rotating drum operating in a rolling regime under different rotating velocity, based on experimental results and simulations. Simple superphosphate fertilizer (SSP) was used as particulate matter in the current study. The Eulerian–Eulerian multiphase model along with the kinetic theory of granular flow was used in the simulations. In order to evaluate the simulation results, velocity distributions of the particulate phase were compared with experimental data. The experimental particle velocity distribution was obtained by using a high speed video camera. The numerical simulation results showed significant insights towards understanding of the particle dynamic in a rotating drum. The simulated results of particle velocity were in good agreement with the experimental data.

Numerical Analysis of the Flow Inside a Centrifugal Compressor’s Vaneless Diffuser and Volute

2001 ◽  
Author(s):  
Hooman Rezaei ◽  
Abraham Engeda ◽  
Paul Haley
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Mass Flow ◽  
Operating Conditions ◽  
Vaneless Diffuser ◽  
Flow Angle ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Minimum Medium ◽  
Good Agreement

Abstract The objective of this work was to perform numerical analysis of the flow inside a modified single stage CVHF 1280 Trane centrifugal compressor’s vaneless diffuser and volute. Gambit was utilized to read the casing geometry and generating the vaneless diffuser. An unstructured mesh was generated for the path from vaneless diffuser inlet to conic diffuser outlet. At the same time a meanline analysis was performed corresponding to speeds and mass flow rates of the experimental data in order to obtain the absolute velocity and flow angle leaving the impeller for those operating conditions. These values and experimental data were used as inlet and outlet boundary conditions for the simulations. Simulations were performed in Fluent 5.0 for three speeds of 2000, 3000 and 3497 RPM and mass flow rates of minimum, medium and maximum. Results are in good agreement with the experimental ones and present the flow structures inside the vaneless diffuser and volute.

Statistical and Theoretical Models of Ingestion Through Turbine Rim Seals

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Kunyuan Zhou ◽  
Simon N. Wood ◽  
J. Michael Owen
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Flow Parameter ◽  
Likelihood Estimation ◽  
Theoretical Models ◽  
Operating Conditions ◽  
Data Points ◽  
Effects Of Rotation ◽  
Effectiveness Data ◽  
Good Agreement

In recent papers, orifice models have been developed to calculate the amount of ingestion, or ingress, that occurs through gas-turbine rim seals. These theoretical models can be used for externally induced (EI) ingress, where the pressure differences in the main gas path are dominant, and for rotationally induced (RI) ingress, where the effects of rotation in the wheel space are dominant. Explicit “effectiveness equations,” derived from the orifice models, are used to express the flow rate of sealing air in terms of the sealing effectiveness. These equations contain two unknown terms: Φmin, a sealing flow parameter, and Γc, the ratio of the discharge coefficients for ingress and egress. The two unknowns can be determined from concentration measurements in experimental rigs. In this paper, maximum likelihood estimation is used to fit the effectiveness equations to experimental data and to determine the optimum values of Φmin and Γc. The statistical model is validated numerically using noisy data generated from the effectiveness equations, and the simulated tests show the dangers of drawing conclusions from sparse data points. Using the statistical model, good agreement between the theoretical curves and several sets of previously published effectiveness data is achieved for both EI and RI ingress. The statistical and theoretical models have also been used to analyze previously unpublished experimental data, the results of which are included in separate papers. It is the ultimate aim of this research to apply the effectiveness data obtained at rig conditions to engine-operating conditions.

Numerical study of fluid flow and power consumption in a stirred vessel with a Scaba 6SRGT impeller

2011 ◽  
Vol 32 (4) ◽  
pp. 351-366 ◽  
Author(s):  
Houari Ameur ◽  
Mohamed Bouzit ◽  
Mustapha Helmaoui
Keyword(s):  
Experimental Data ◽  
Fluid Flow ◽  
Power Consumption ◽  
Yield Stress ◽  
Short Distance ◽  
Numerical Study ◽  
Stirred Vessel ◽  
Higher Power ◽  
Shear Thinning Fluid ◽  
Good Agreement

Numerical study of fluid flow and power consumption in a stirred vessel with a Scaba 6SRGT impeller The present work deals with agitation of non-Newtonian fluids in a stirred vessel by Scaba impellers. A commercial CFD package (CFX 12.0) was used to solve the 3D hydrodynamics and to characterise at every point flow patterns especially in the region swept by the impeller. A shear thinning fluid with yield stress was modelled. The influence of agitator speed, impeller location and blade size on the fluid flow and power consumption was investigated. The results obtained are compared with available experimental data and a good agreement is observed. It was found that an increase in blade size is beneficial to enlargement of the well stirred region, but that results in an increased power consumption. A short distance between the impeller and the tank walls limits the flow around the agitator and yields higher power consumption. Thus, the precise middle of the tank is the most appropriate position for this kind of impeller.

Theoretical studies of the anisotropic g factors for deoxygenated Y123

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542017
Author(s):  
L. J. Zhang ◽  
S. Y. Wu ◽  
C. C. Ding ◽  
Y. K. Cheng
Keyword(s):  
Experimental Data ◽  
Orbit Coupling ◽  
Theoretical Studies ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Ligand Orbital ◽  
Y123 System ◽  
Good Agreement ◽  
G Factors

The anisotropic [Formula: see text] factors of the deoxygenated YBaCuO (Y123) are theoretically studied using the perturbation formulas of the [Formula: see text] factors for a tetragonally elongated octahedral [Formula: see text] cluster. The ligand orbital and spin-orbit coupling contributions are included from the cluster approach in view of covalency. The calculated [Formula: see text] factors show good agreement with the experimental data. The anisotropy of the [Formula: see text] factors is analyzed by considering the local tetragonal elongation distortion around this five-fold coordinated [Formula: see text] site in the deoxygenated Y123 system.

A semianalytical and numerical study of penetration and perforation of an ogive-nose projectile into concrete targets under normal impact

2011 ◽  
Vol 225 (8) ◽  
pp. 1782-1797 ◽  
Author(s):  
S Seifoori ◽  
G H Liaghat
Keyword(s):  
Experimental Data ◽  
Numerical Study ◽  
Finite Element Code ◽  
Governing Equations ◽  
Normal Impact ◽  
Residual Velocity ◽  
Conservation Of Energy ◽  
Axial Forces ◽  
Shear Plugging ◽  
Good Agreement

In this article, a semianalytical model is proposed to predict the penetration depth of an ogive-nose projectile into a concrete target. In addition, the theory of shear plugging is used to calculate the residual velocity of the projectile following complete perforation of the target. In this analysis, which is based on the Forrestal model, conservation of energy was employed to determine the axial forces on the projectile and target during both the penetration and perforation stages and the governing equations were derived in each case. The tests were then simulated numerically with the finite element code LS-DYNA and good agreement was obtained with both experimental data and the predictions of the analytical model.

scholarly journals Experimental and numerical study of granular flow and fence interaction

2004 ◽  
Vol 38 ◽  
pp. 135-138 ◽  
Author(s):  
Thierry Faug ◽  
Mohamed Naaim ◽  
Florence Naaim-Bouvet
Keyword(s):  
Granular Flow ◽  
Numerical Study ◽  
Slope Angle ◽  
Granular Flows ◽  
Snow Avalanches ◽  
Shallow Water Theory ◽  
Gravity Driven ◽  
Deposition Processes ◽  
Set Up ◽  
Good Agreement

AbstractDense snow avalanches are regarded as dry granular flows. This paper presents experimental and numerical modelling of deposition processes occurring when a gravity-driven granular flow meets a fence. A specific experimental device was set up, and a numerical model based on shallow-water theory and including a deposition model was used. Both tools were used to quantify how the retained volume upstream of the fence is influenced by the channel inclination and the obstacle height. We identified two regimes depending on the slope angle. In the slope-angle range where a steady flow is possible, the retained volume has two contributions: deposition along the channel due to the roughness of the bed and deposition due to the fence. The retained volume results only from the fence effects for higher slopes. The effects of slope on the retained volume also showed these two regimes. For low slopes, the retained volume decreases strongly with increasing slope. For higher slopes, the retained volume decreases weakly with increasing slope. Comparison between the experiments and computed data showed good agreement concerning the effect of fence height on the retained volume.

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.

Perturbed Flow Structure in an Annular Seal Due to Synchronous Whirl

1994 ◽  
Vol 116 (3) ◽  
pp. 564-569
Author(s):  
E. A. Baskharone
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Flow Field ◽  
Operating Conditions ◽  
Clearance Ratio ◽  
Perturbation Model ◽  
Eccentric Rotor ◽  
Annular Seal ◽  
The Common ◽  
Good Agreement

This paper provides a thorough examination of the flow field resulting from synchronous whirl of an eccentric rotor in an annular seal under typical operating conditions. A new finite-element-based perturbation model is employed in the analysis, whereby perturbations in the flow thermophysical properties are attributed to virtual distortions in the rotor-to-housing finite element assembly. The numerical results are compared to a recent set of experimental data for a hydraulic seal with typical geometrical configurations and a synchronously whirling rotor. Despite the common perception that perturbation analyses are categorically confined to small rotor eccentricities, good agreement between the computed flow field and the experimental data is obtained for an eccentricity/clearance ratio of 50 percent. The agreement between the two sets of data is notably better at axial locations where the real-rig flow admission losses have diminished, and up to the seal discharge station. This attests to the accuracy of this untraditional and highly versatile perturbation model in predicting the rotordynamic characteristics of this and a wide variety of conceptually similar fluid/rotor interaction problems.

Formation of solitons in transitional boundary layers: theory and experiment

1993 ◽  
Vol 251 ◽  
pp. 273-297 ◽  
Author(s):  
Y. S. Kachanov ◽  
O. S. Ryzhov ◽  
F. T. Smith
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Asymptotic Theory ◽  
Subsequent Development ◽  
Boundary Layer Transition ◽  
Theoretical Studies ◽  
Layer Transition ◽  
Experimental And Theoretical Studies ◽  
Theory And Experiment ◽  
Good Agreement

This work brings together experimental and theoretical studies of nonlinear stages aimed at the K-regime in boundary-layer transition, and some combined theoretical and experimental results are discussed. It is shown that the initial stages in the formation of so-called spikes, observed in many experiments, may be described very well by the asymptotic theory. These flashes-spikes are shown to be (in certain regimes) possible solitons of the boundary layer and governed by the integral-differential Benjamin-Ono equation. Properties of the spike-solitons, obtained both theoretically and experimentally in the quasi-planar stages of their development, are presented. Features of the disturbance behaviour connected with the subsequent development of three-dimensionality are also discussed, as are the effects of viscosity and shorter lengthscales. The main conclusion of the work concerns the hypothesis of the possible soliton nature of the flashes-spikes (within limits), which seems reliably corroborated by the good agreement found between the theory and the experimental data.

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