Grain Flow for Rough Surfaces Considering Grain/Grain Collision Elasticity

2005 ◽  
Vol 127 (4) ◽  
pp. 837-844 ◽  
Author(s):  
Yeau-Ren Jeng ◽  
Hung-Jung Tsai
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Energy Loss ◽  
Collision Energy ◽  
Surface Characteristics ◽  
Roughness Effects ◽  
Lubrication Equation ◽  
Grain Flow ◽  
Mathematical Formulas ◽  
Good Agreement

Previous work by this group on an average lubrication equation for grain flow with roughness effects is extended to include grain-grain collision elasticity ranging from perfectly elastic to perfectly inelastic. The average lubrication equation is based on Haff’s grain flow theory, with flow factors from Patir and Cheng and Tripp’s use of perturbation. The derived flow factors are obtained as functions of rough surface characteristics, grain size, and collision pattern. As collision energy loss approaches zero, the inelastic results approach those for perfectly elastic grain collision. The mathematical formulas for flow factors, grain/grain collision elasticity, grain size, and roughness are presented and discussed. Predicitons for the elastic and inelastic cases are graphically demonstrated and compared. The derived average lubrication equation for grain flow shows good agreement with the theoretical and experimental data of Yu, Craig, and Tichy [J. Rheol., 38(4), 921 (1994)].

Grain Flow for Rough Surfaces Considering Elastic/Inelastic Grain Collision

2004 ◽  
Author(s):  
Yeau-Ren Jeng ◽  
Hung-Jung Tsai
Keyword(s):  
Grain Size ◽  
Energy Loss ◽  
Rough Surface ◽  
Collision Energy ◽  
Rough Surfaces ◽  
Surface Characteristics ◽  
Flow Theory ◽  
Roughness Effects ◽  
Lubrication Equation ◽  
Grain Flow

Previous work by this group on an average lubrication equation for grain flow with roughness effects is extended to include grain-grain collision elasticity ranging from perfectly elastic to perfectly inelastic. The average lubrication equation is based on Haff’s grain flow theory, with flow factors from Patir and Cheng and Tripp’s use of perturbation. The derived flow factors are obtained as functions of rough surface characteristics, grain size and collision pattern. As collision energy loss approaches zero, the inelastic results approach those for perfectly elastic grain collision. The mathematical formulae for flow factors, grain/grain collision elasticity, grain size and roughness are presented, discussed. Predictions for the elastic and inelastic cases are graphically demonstrated and compared.

An Average Lubrication Equation for Thin Film Grain Flow With Surface Roughness Effects

2002 ◽  
Vol 124 (4) ◽  
pp. 736-742 ◽  
Author(s):  
Hung-Jung Tsai ◽  
Yeau-Ren Jeng
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Particle Size ◽  
Coordinate Transformation ◽  
Surface Characteristics ◽  
Perturbation Approach ◽  
Roughness Effects ◽  
Lubrication Equation ◽  
Grain Flow ◽  
Standard Derivation

A closed-form average lubrication equation for thin film grain flow with the effects of surface roughness is derived. This equation is based on Haff’s grain flow theory and also the flow factors proposed by Patir and Cheng. The flow factors, derived by the perturbation approach and coordinate transformation, are expressed in terms of surface characteristics (three characteristics for each surface: roughness orientation, Peklenik number and standard derivation) and particle size. Finally, the flow factors under different surface characteristics and particle size are discussed.

scholarly journals A Method of Predicting the Energy Losses in Vaneless Diffusers of Centrifugal Compressors

1989 ◽  
Author(s):  
Huashu Dou
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Total Energy ◽  
Wall Friction ◽  
Energy Losses ◽  
Flow Conditions ◽  
Centrifugal Compressors ◽  
Flow Losses ◽  
Vaneless Diffusers ◽  
Good Agreement

The flow losses in the veneless diffusers of centrifugal compressors is investigated. It is found that the total energy loss in vaneless diffusers is a function of Bsin2 α0 when inlet flow conditions and radius ratio between inlet and outlet are given. A wall friction coefficient equation is derived and a method of predicting the total energy loss excepting mixing loss is presented. A comparison is made between results obtained from this method and experimental data generated by the author as well as data from the literature. Good agreement is obtained.

Microstructure Evolution in Undercooled Ni-Si Melt

2013 ◽  
Vol 749 ◽  
pp. 349-355
Author(s):  
Kai Fan ◽  
Feng Liu ◽  
Bao Quan Fu ◽  
Wen Zhong Luo ◽  
Yao He Zhou
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Grain Refinement ◽  
Microstructure Evolution ◽  
Solid Solubility ◽  
Molten Glass ◽  
Dendrite Fragmentation ◽  
Equilibrium Solidification ◽  
Good Agreement ◽  
Non Equilibrium

Upon non-equilibrium solidification, the intrinsic parameters, such as moving velocity, temperature, solute partition coefficient, and liquid and solid concentrations at the interface, deviate from their equilibrium characteristics, and the morphology of the as-solidified structure and the grain size are influenced by the non-equilibrium liqulid/solid transformation, which further influences the subquent solidstate transformation. Adopting molten glass purification technology combined with cycle superheating method, the microstructure evolution of Ni-11at.%Si alloy in different undercooling was investigated. It was found that, with the increase of the initial undercooling, grain refinement occurred in microstructures of undercooled Ni-11at.%Si alloy. Meanwhile, the NL model was used to discuss the two different dendrite morphologies. According to Karmas model for dendrite fragmentation, the grain refinement of undercooled Ni-11at.%Si alloy was in good agreement with the experimental data, and the grain size was reduced with the increasing ΔT. The energy-dispersive spectroscopy (EDS) measurement was applied to analyze the solid solubility of Si atom in α-Ni matrix. It was found that the solid solubility of Si atom in α-Ni matrix increased with undercooling. At the undercooling of T>220K , a complete solute trapping occurred.

New Model for Characterization of Dynamic Recrystallization and Prediction of Grain Size Applied to Two Wrought Magnesium Alloys

2008 ◽  
Vol 604-605 ◽  
pp. 87-96 ◽  
Author(s):  
Ignacio Rieiro ◽  
Jesus Castellanos ◽  
Manuel Carsí ◽  
Julio Muñoz ◽  
Oscar A. Ruano
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Dynamic Recrystallization ◽  
Magnesium Alloys ◽  
Linear Optimization ◽  
Optimization Methods ◽  
Size Refinement ◽  
Strain Dependent ◽  
Good Agreement

A model for describing the plastic flow has been developed. The model is based on a strain dependent Garofalo equation and predicts the variation with strain of grain size refinement by dynamic recrystallization using non-linear optimization methods. The predictions have been applied to two wrought magnesium alloys, AZ31 and AZ61 and are in good agreement with experimental data.

Study on Microstructure Evolution in GH4169 Alloy Blade during Finish Forging

2012 ◽  
Vol 217-219 ◽  
pp. 1671-1675 ◽  
Author(s):  
Guang Xia Qi ◽  
Rui Bin Mei ◽  
Na Cao
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Grain Size ◽  
Dynamic Recrystallization ◽  
Microstructure Evolution ◽  
Prediction Error ◽  
Compression Tests ◽  
Deform 3D ◽  
Gh4169 Alloy ◽  
Good Agreement

Constitutive equations and dynamic recrystallization (DRX) model of GH4169 alloy were investigated using compression tests with temperature 940(°C)-1060(°C) and strain rate 0.001(s-1)-0.1(s-1). A coupled numerical simulation between thermal-mechanical and microstructure evolution was realized through embedding the developed user subroutines into the FEM software DEFORM-3D system. The simulated results show that higher speed of upper die is useful to the DRX but much higher and lower speed of upper die go against improving the finer and uniform of grain size in the blade. Furthermore, the grains are finer and uniform in the blade body compared with those of blade rabbet and damper platform. The experimental results of microstructure under the same forging condition were studied and the average grain degrees in the blade are over 9. The calculated results of microstructure have a good agreement with the measured value from experimental data and the prediction error is less than 7.0%. Therefore, the DRX model and developed program is reliable to optimize and improve the parameters in the blade finish forging.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Predicting the Effect of Tire Tread Pattern Design on Thick Film Wet Traction

1977 ◽  
Vol 5 (1) ◽  
pp. 6-28 ◽  
Author(s):  
A. L. Browne
Keyword(s):  
Experimental Data ◽  
Network Design ◽  
Thick Film ◽  
Digital Computer ◽  
Analytical Tool ◽  
Design Practice ◽  
Pattern Design ◽  
Performance Results ◽  
Good Agreement

Abstract An analytical tool is presented for the prediction of the effects of changes in tread pattern design on thick film wet traction performance. Results are reported for studies in which the analysis, implemented on a digital computer, was used to determine the effect of different tread geometry features, among these being the number, width, and lateral spacing of longitudinal grooves and the angle of zigzags in longitudinal grooves, on thick film wet traction. These results are shown to be in good agreement with experimental data appearing in the literature and are used to formulate guidelines for tread groove network design practice.

A New Condition of Formation and Stablity of All Crystalline Systems in a Good Agreement with Experimental Data

2015 ◽  
Vol 11 (3) ◽  
pp. 3224-3228
Author(s):  
Tarek El-Ashram
Keyword(s):  
Experimental Data ◽  
Brillouin Zone ◽  
Electron Concentration ◽  
Free Electron ◽  
Lattice Point ◽  
Valence Electron ◽  
Fermi Gas ◽  
Valence Electron Concentration ◽  
Fermi Sphere ◽  
Good Agreement

In this paper we derived a new condition of formation and stability of all crystalline systems and we checked its validity andit is found to be in a good agreement with experimental data. This condition is derived directly from the quantum conditionson the free electron Fermi gas inside the crystal. The new condition relates both the volume of Fermi sphere VF andvolume of Brillouin zone VB by the valence electron concentration VEC as ;𝑽𝑭𝑽𝑩= 𝒏𝑽𝑬𝑪𝟐for all crystalline systems (wheren is the number of atoms per lattice point).

Virus Removal by Filtration

1982 ◽  
Vol 14 (4-5) ◽  
pp. 253-256
Author(s):  
N Sriramula ◽  
M Chaudhuri
Keyword(s):  
Experimental Data ◽  
Escherichia Coli ◽  
Cationic Polyelectrolyte ◽  
Electrokinetic Phenomena ◽  
Virus Removal ◽  
Bacterial Virus ◽  
Gravity Settling ◽  
And Diffusion ◽  
Model Virus ◽  
Good Agreement

An investigation was undertaken on the removal of a model virus, bacterial virus MS2 against Escherichia coli, by sand filtration using untreated, and alum or cationic polyelectrolyte treated media, and uncoagulated as well as alum coagulated influent. Data on discrete virus removal were satisfactorily accounted for by electrokinetic phenomena and diffusion. For virus in association with turbidity, filter coefficients computed from experimental data were in good agreement with those predicted by mechanical straining and gravity settling which were the dominant mechanisms for removal of the turbidity particles to which the viruses attached.

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