Fabrication and numerical verification of two-dimensional random aggregate virtual specimens for asphalt mixture

2021 ◽  
Vol 279 ◽  
pp. 122455
Author(s):  
Sheng Liang ◽  
Rong Luo
Keyword(s):  
Asphalt Mixture ◽  
Numerical Verification ◽  
Two Dimensional ◽  
Random Aggregate

scholarly journals Two Dimensional Elastic Analysis for Asphalt Mixture on Steel Plate.

1999 ◽  
pp. 303-314
Author(s):  
Shoichi AKIBA ◽  
Yuzou KURIYAGAWA ◽  
Sumio G. NOMACHI ◽  
Narioki AKIYAMA
Keyword(s):  
Steel Plate ◽  
Asphalt Mixture ◽  
Elastic Analysis ◽  
Two Dimensional

Experimental and Numerical Verification of the Core-Flow in a New Low-Pressure Turbine

2016 ◽  
Author(s):  
Michael Henke ◽  
Lars Wein ◽  
Tim Kluge ◽  
Yavuz Guendogdu ◽  
Marc Heinz-Otto Biester ◽  
...  
Keyword(s):  
Flow Field ◽  
Low Pressure ◽  
Numerical Verification ◽  
Two Dimensional ◽  
Core Flow ◽  
Low Pressure Turbine ◽  
The Core ◽  
Blade Row ◽  
Unsteady Effects ◽  
Blade Row Interaction

The flow field in modern axial turbines is non-trivial and highly unsteady due to secondary flow and blade row interaction. In recent years, existing design-tools like two-dimensional flow solvers as well as fully three-dimensional CFD methods have been validated for the assumption of a quasi-steady flow field. Since the inevitable unsteadiness of the flow field has a direct impact on unsteady loss generation and work transfer, existing design methods stand in need of validation for local unsteady effects within the flow field. In order to clearly separate end-wall losses from those generated by blade row interaction within the blade passage, a two-dimensional core-flow is essential for the investigation. Hence, a new 1.5-stage high aspect ratio low pressure turbine has been designed to determine the intensity of core-flow blade row interaction for different axial gaps. First, inlet and outlet conditions of the test rig are evaluated with regard to homogeneity of the flow parameters in their radial and circumferential distributions. Secondly, the measurement data gained from rig tests have been applied as boundary conditions to time-averaged numerical computations. The flow field analysis for two different axial gaps focuses on the verification of the core flow. The authors show that the new turbine has been successfully verified using both test data and the numerical predictions, serving as a precondition for the validation of the numerical model for unsteady effects within the core-flow.

scholarly journals Excitation of surface plasmon waves with a nanoantenna: simple analytical solution and its numerical verification

2020 ◽  
Vol 44 (6) ◽  
pp. 893-900
Author(s):  
A.V. Dyshlyuk ◽  
A.A. Bogdanov ◽  
O.B. Vitirk
Keyword(s):  
Surface Plasmon ◽  
Time Domain ◽  
Dielectric Waveguide ◽  
Analytical Approach ◽  
Reciprocity Theorem ◽  
Numerical Verification ◽  
Two Dimensional ◽  
Waveguide Modes ◽  
Plasmon Polaritons ◽  
A Current

In this work, we demonstrate a simple analytical approach to the problem of surface plasmon polaritons excitation with a metallic nanoantenna placed above a metal surface. The method uses the reciprocity theorem and is similar to the calculation of amplitudes of dielectric waveguide modes excited by a current distribution. To maximize clarity of the demonstration, we formulate the problem in a simple two-dimensional geometry. The analytical results are shown to agree well with the numerical solution obtained by finite elements in frequency domain and finite difference in time domain methods.

Experimental and Numerical Verification of Effect of Using Curvilinear Element Blades for Low-Solidity Cascade Diffuser in Centrifugal Compressor

2017 ◽  
Author(s):  
Kazuhiro Tsukamoto ◽  
Kiyotaka Hiradate ◽  
Kiyohide Sakamoto ◽  
Yasushi Shinkawa
Keyword(s):  
Performance Improvement ◽  
Centrifugal Compressor ◽  
Recirculation Region ◽  
Numerical Verification ◽  
Two Dimensional ◽  
Suction Surface ◽  
Design Point ◽  
Operating Range ◽  
Setting Angle ◽  
Low Solidity Cascade Diffuser

The effect of using curvilinear element blades (CEBs) on a low-solidity cascade diffuser (LSD) in a centrifugal compressor was investigated both experimentally and numerically. Centrifugal compressors require a higher efficiency and wider operating range to reduce the lifecycle costs of plants in which they are used and the effects their users have on the environment. A LSD has a wider operating range than a common vaned diffuser that has high solidity, but worse efficiency at the design point. For this reason, this research aims to improve the efficiency of the LSD and keep its operating range wide without changing the blade setting angle or two-dimensional geometry. As a first step, LSDs with three different curvilinear element profiles were compared with a conventional LSD, and the mechanism of the performance improvement was investigated by using a numerical simulation. These diffusers have the same two-dimensional geometry, blade setting angle, and number of blades but different blade stacking geometry in the span-wise direction. Unsteady Reynolds Averaged Navier-Stokes (RANS) simulations were conducted using a one-blade path model with an inlet, impeller, and LSD diffuser passages. The LSD using the CEBs improved the efficiency by 1.9% over that of the conventional LSD at the design point while maintaining the same operating range. The calculation results reveal that the recirculation region decreased at the suction surface of the diffuser vane in the CEB case and the diffuser efficiency improved. The concaved suction surface increased the blade loading and induced higher velocity on the suction surface. The higher velocity prevented reverse flow on the suction surface at the hub side, and the secondary flow removed the thick boundary layer at the trailing edge to the downstream of the diffuser. Experimental verification was also conducted using a single-stage compressor with an impeller, diffuser, and scroll casing to verify the prediction. The experimental results showed the LSD using the CEB has a higher pressure rise at the stator region than the conventional LSD and verified the performance improvement due to using the CEBs.

Application of Random Aggregate Model to the Problem of Concrete Penetration

2012 ◽  
Vol 446-449 ◽  
pp. 546-549
Author(s):  
Yi Zeng ◽  
Jun Lin Tao ◽  
Yong Yao ◽  
Xiao Ling Liu ◽  
Qian Hui Ren
Keyword(s):  
High Strain ◽  
Constitutive Relations ◽  
Large Strains ◽  
Two Dimensional ◽  
Penetration Test ◽  
Convex Polygons ◽  
Aggregate Model ◽  
Random Aggregate ◽  
Random Aggregate Model ◽  
Random Convex

Penetration of concrete targets was simulated based on self-compiled program generating two-dimensional random aggregate model. Random convex polygons were used to simulate the aggregate particles of concrete, HJC model to describe constitutive relations of the aggregates and mortar while concrete targets are subjected to large strains, high pressure and high strain rate. With this model, the Forrestal's penetration test was simulated by ls-dyna software. By comparing the calculated results with the test data, It is shown that random aggregate model can be applied to simulate the dynamic destruction problems of concrete-like materials.

Ergodic properties of inviscid truncated models of two-dimensional incompressible flows

1975 ◽  
Vol 69 (4) ◽  
pp. 673-688 ◽  
Author(s):  
C. Basdevant ◽  
R. Sadourny
Keyword(s):  
Numerical Model ◽  
Finite Number ◽  
Degrees Of Freedom ◽  
Incompressible Flows ◽  
Microcanonical Ensemble ◽  
Numerical Verification ◽  
Two Dimensional ◽  
Ergodic Properties

The equilibrium spectra of two-dimensional numerical model flows are studied from the viewpoint of microcanonical ensemble averages. The method leads to accurate numerical verification of the ergodic, or mixing, hypothesis in the case of systems constrained to a finite number of degrees of freedom.

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