Evaluation and Analysis of Curvature-Corrected Filter-based Turbulent Model

2017 ◽  
Vol 34 (3) ◽  
Author(s):  
Rui Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Calculation ◽  
Correction Term ◽  
Two Dimensional ◽  
Turbulent Model ◽  
Engineering Applications ◽  
Streamline Curvature ◽  
Naca0012 Airfoil ◽  
Proposed Model ◽  
Good Agreement

AbstractPrediction of the characteristics of turbulent flow with streamline curvature is of great importance in engineering applications. In this paper, a curvature-corrected filter-based turbulent model is suggested by applying the Spalart-Shur correction term. This new version of the model (FBM-CC) has been tested and verified through two canonical benchmarks with strong streamline curvature: the flow in a two-dimensional U-duct and the free shear flow past NACA0012 airfoil with a round tip. Predictions of the FBM-CC model are compared with available experimental data and the corresponding results of the original FBM model. The numerical results show that the FBM-CC model significantly improves the sensitivity to the effect of streamline curvature and the numerical calculation accuracy, in relatively good agreement with the experimental data, which suggests that this proposed model may be employed to simulate the turbulent curved flow in engineering applications.

Correction for Streamline Curvature and Coriolis Force in a Boundary Layer Integral Method

1981 ◽  
Author(s):  
R. A. Van Den Braembussche ◽  
P. Zunino
Keyword(s):  
Experimental Data ◽  
Integral Method ◽  
Theoretical Calculations ◽  
Correction Term ◽  
Dissipation Factor ◽  
Coriolis Forces ◽  
Streamline Curvature ◽  
Rotation Numbers ◽  
Wide Range ◽  
Good Agreement

The influence of Coriolis forces and streamwise curvature on boundary layers has been introduced into an integral method by adding a correction term to the dissipation factor. This correction term is related to Coriolis forces and streamline curvature in terms of a parameter 13 which was determined using existing experimental data. Theoretical calculations using this value of show good agreement with experimental results for a wide range of curvature and rotation numbers representing realistic conditions for turbomachinery applications.

scholarly journals Modelling the Characteristics of Ring-Shaped Magnetoelastic Force Sensor in Mohri’s Configuration

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 266 ◽  
Author(s):  
Anna Ostaszewska-Liżewska ◽  
Roman Szewczyk ◽  
Peter Raback ◽  
Mika Malinen
Keyword(s):  
Experimental Data ◽  
High Sensitivity ◽  
Force Sensor ◽  
Inhomogeneous Distribution ◽  
The Finite Element Method ◽  
The Core ◽  
Magnetoelastic Effect ◽  
Proposed Model ◽  
Distribution Of Stresses ◽  
Good Agreement

Magnetoelastic force sensors exhibit high sensitivity and robustness. One commonly used configuration of force sensor with a ring-shaped core was presented by Mohri at al. In this configuration force is applied in the direction of a diameter of the core. However, due to inhomogeneous distribution of stresses, model of such sensor has not been presented yet. This paper is filling the gap presenting a new method of modelling the magnetoelastic effect, which is especially suitable for the finite element method. The presented implementation of proposed model is in good agreement with experimental data and creates new possibilities of modelling other devices utilizing magnetoelastic effect.

Analysis and Validation of Cutting Forces Prediction Models in Micromachining

2006 ◽  
Vol 526 ◽  
pp. 13-18 ◽  
Author(s):  
H. Perez ◽  
Antonio Vizan Idoipe ◽  
J. Perez ◽  
J. Labarga
Keyword(s):  
Experimental Data ◽  
Cutting Force ◽  
Cutting Forces ◽  
Prediction Models ◽  
Precision Machining ◽  
New Model ◽  
Proposed Model ◽  
On Line ◽  
Machine Control ◽  
Good Agreement

Many investigations have been developed related to precision machining with features in the millimetre scale. In this paper different cutting force models for micromilling are analyzed and compared. A new model based on specific cutting force that also considers run-out errors has been developed. The estimated cutting forces obtained with this model had good agreement with the experimental data. Also, the proposed model allows to be implemented within the machine control for the on-line optimization of the micromilling process.

The Formation of Molecules in Three Atom Collisions using the Eikonal Approximation

1976 ◽  
Vol 31 (12) ◽  
pp. 1489-1499
Author(s):  
E. Czuchaj
Keyword(s):  
Experimental Data ◽  
Numerical Calculation ◽  
Rate Constant ◽  
Recombination Rate ◽  
Eikonal Approximation ◽  
New Approach ◽  
Order Of Magnitude ◽  
Recombination Rate Constant ◽  
Good Agreement

Abstract A new approach to the calculation of a teratomic recombination rate constant k(T) has been dem-onstrated. An expression for k(T) has been obtained in the eikonal approximation. The numerical calculation has been carried out for the Rb*-Xe system. Good agreement in the order of magnitude between the present results and the experimental data of Carrington et al. has been obtained.

Novel Model for the Optical Function: Application to Hexagonal Gan

2001 ◽  
Vol 677 ◽  
Author(s):  
Y. Chan ◽  
Aleksandra B. Djurišić ◽  
E. Herbert Li
Keyword(s):  
Experimental Data ◽  
Closed Form ◽  
Dielectric Function ◽  
Absorption Edge ◽  
Low Energy ◽  
Optical Function ◽  
Complex Dielectric Function ◽  
Proposed Model ◽  
Novel Model ◽  
Good Agreement

ABSTRACTIn this work we propose an analytical expression for the complex dielectric function that includes both discrete and continuum exciton effects. The model is based on the work of Elliott and the proposed model has been applied to modeling the experimental data for the hexagonal GaN. We have obtained good agreement with the experimental data. The model assumes Lorentzian broadening in order to obtain dielectric function equations in analytically closed form. We show that Lorentzian broadened dielectric function decays more slowly than the experimental data for hexagonal GaN at the low energy side. This indicates that the broadening of the absorption edge in GaN is not purely Lorentzian. The agreement with the experimental data can be improved using adjustable broadening modification.

Design Methods of Volute Casings for Turbocharger Turbine Applications

1996 ◽  
Vol 210 (2) ◽  
pp. 149-156 ◽  
Author(s):  
H Chen
Keyword(s):  
Experimental Data ◽  
Potential Flow ◽  
Design Method ◽  
Three Dimensional ◽  
Design Methods ◽  
Two Dimensional ◽  
Aerodynamic Design ◽  
3D Design ◽  
Flow Equations ◽  
Good Agreement

This paper discusses aerodynamic design methods of volute casings used in turbocharger turbines. A quasi-three-dimensional (Q-3D) design method is proposed in which a group of extended two-dimensional potential flow equations and the streamline equation are numerically solved to obtain the geometry of spiral volutes. A tongue loss model, based on the turbulence wake theory, is also presented, and good agreement with experimental data is shown.

Calculation of the effect of polymer additive in a converging flow

1987 ◽  
Vol 178 ◽  
pp. 423-440 ◽  
Author(s):  
G. Ryskin
Keyword(s):  
Stress Field ◽  
Channel Flow ◽  
Molecular Model ◽  
Two Dimensional ◽  
Polymer Additive ◽  
Polymer Molecules ◽  
Conical Channel ◽  
Proposed Model ◽  
Converging Flow ◽  
Good Agreement

The conical-channel flow of a dilute polymer solution is investigated theoretically. The stress field due to polymer additive is calculated using a new molecular model, based on the physical picture of the polymer molecules unravelling in strong flows and Batchelor's theory for the stress in a suspension of elongated particles. Good agreement is obtained with the experimental results of James & Saringer (1980). The absence of a significant polymer effect in a two-dimensional case (the wedge-channel flow), observed by the same authors (James & Saringer 1982a), is also explained. The fundamental differences between the proposed model and the elastic-dumbbell models are discussed.

Study of viscosity on the fission dynamics of the excited nuclei 228U produced in 19F + 209Bi reactions

2015 ◽  
Vol 24 (07) ◽  
pp. 1550052 ◽  
Author(s):  
H. Eslamizadeh
Keyword(s):  
Experimental Data ◽  
Symmetry Axis ◽  
Measured Data ◽  
Total Spin ◽  
Langevin Equations ◽  
Two Dimensional ◽  
Excitation Energies ◽  
Fission Fragments ◽  
Excited Nuclei ◽  
Good Agreement

A two-dimensional (2D) dynamical model based on Langevin equations was applied to study the fission dynamics of the compound nuclei 228 U produced in 19 F + 209 Bi reactions at intermediate excitation energies. The distance between the centers of masses of the future fission fragments was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis, K, was considered as the second dimension in Langevin dynamical calculations. The magnitude of post-saddle friction strength was inferred by fitting measured data on the average pre-scission neutron multiplicity for 228 U . It was shown that the results of calculations are in good agreement with the experimental data by using values of the post-saddle friction equal to 6–8 × 1021 s -1.

scholarly journals Thermodynamic modelling of the binary indium-lithium system, a promising li-ion battery material

2021 ◽  
pp. 41-41
Author(s):  
Wojciech Gierlotka ◽  
Władysław Gąsior ◽  
Adam Dębski ◽  
Miłosz Zabrocki
Keyword(s):  
Experimental Data ◽  
Ternary Systems ◽  
Calphad Approach ◽  
Li Ion Battery ◽  
System A ◽  
Proposed Model ◽  
Component Systems ◽  
Li Ion ◽  
Battery Material ◽  
Good Agreement

The binary In - Li system is a promising Li-ion battery anode material as well as a part of the important ternary Ge - In - Li system. The thermodynamic descriptions of metallic systems are widely used to retrieve information necessary for alloy applications. In this work, a thermodynamic model of a binary indium - lithium system prepared by the Calphad approach is proposed. The liquid phase was described by an associate model, and the solid phases determined by the ab-initio calculation were included in thermodynamic modeling. The obtained set of self-consistent thermodynamic parameters well reproduces the available experimental data and enables further calculations of multi-component systems. A good agreement between the calculations and the available experimental data was found. The proposed model can be used for further descriptions of ternary systems.

scholarly journals MODELING OF ELASTIC-PLASTIC DEFORMATION OF ELEMENTS OF SPATIAL STRUCTURES DURING PULSE INTERACTION WITH FLUID BASED ON THE GODUNOV'S METHOD OF INCREASED ACCURACY

2019 ◽  
Vol 81 (4) ◽  
pp. 488-499
Author(s):  
Wang Cheng ◽  
Yang Tonghui ◽  
Li Wan ◽  
Tao Li ◽  
M.H. Abuziarov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shock Waves ◽  
Elastoplastic Deformation ◽  
Three Dimensional ◽  
Numerical Results ◽  
Two Dimensional ◽  
Wave Processes ◽  
Detonation Products ◽  
Comparison Of The Results ◽  
Good Agreement

The spatial problem of internal explosive loading of an elastoplastic cylindrical container filled with water in Eulerian - Lagrangian variables using multigrid algorithms is considered. A defining system of three-dimensional equations of the dynamics of gas, fluid, and elastoplastic medium is presented. For numerical modeling, a modification of S.K. Godunov scheme of the increased accuracy for both detonation products and liquids, and elastoplastic container is used. At the moving contact boundaries “detonation products - liquid”, “liquid - deformable body”, the exact solution of the Riemann's problem is used. A time dependent model is used to describe the propagation of steady-state detonation wave through an explosive from an initiation region. In both cases, the initiation of detonation occurs at the center of the charge. Two problems have been solved: the first task for the aisymmetric position of the charge, the second for the charge shifted relative to the axis of symmetry. In the first task, the processes are two-dimensional axisymmetric in nature, in the second task, the processes are essentially three-dimensional. A comparison is made of the results of calculations of the first problem using a three-dimensional method with a solution using a previously developed two-dimensional axisymmetric method and experimental data. Good agreement is observed between the numerical results for the maximum velocities and circumferential strains obtained by various methods and experimental data. There is good agreement between the numerical results obtained by various methods and the known experimental data. Comparison of the results of solving the first and second problems shows a significant effect of the position of the charge on the wave processes in the liquid, the processes of loading the container and its elastoplastic deformation. The dynamic behavior of a gas bubble with detonation products is analyzed. A significant deviation of the bubble shape from the spherical one, caused by the action of shock waves reflected from the structure, is shown. Comparison of the results of solving the first and second problems showed a significant effect of the charge position on wave processes in a liquid, the processes of loading a container and its elastoplastic deformation. In particular, in the second problem, shock waves of higher amplitude are observed in the liquid when reflected from the walls of the container.

Sign in / Sign up

Export Citation Format

Share Document