Numerical simulation of the equilibrium of an elastic two-layer structure with a crack

Purpose The centrifugal instability mechanism of boundary layers over concave surfaces is responsible for the development of quasi-periodic, counter-rotating vortices aligned in a streamwise direction known as Görtler vortices. By distorting the boundary layer structure in both the spanwise and the wall-normal directions, Görtler vortices may modify heat transfer rates. The purpose of this study is to conduct spatial numerical simulation experiments based on a vorticity–velocity formulation of the incompressible Navier–Stokes system of equations to quantify the role of the transition in the heat transfer process. Design/methodology/approach Experiments are conducted using an in-house, parallel, message-passing code. Compact finite difference approximations and a spectral method are used to approximate spatial derivatives. A fourth-order Runge–Kutta method is adopted for time integration. The Poisson equation is solved using a geometric multigrid method. Findings Results show that the numerical method can capture the physics of transitional flows over concave geometries. They also show that the heat transfer rates in the late stages of the transition may be greater than those for either laminar or turbulent ones. Originality/value The numerical method can be considered as a robust alternative to investigate heat transfer properties in transitional boundary layer flows over concave surfaces.

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Numerical simulation of equilibrium of an elastic two-layer structure with a through crack

Numerical Analysis and Applications ◽

10.1134/s1995423917010074 ◽

2017 ◽

Vol 10 (1) ◽

pp. 63-73 ◽

Cited By ~ 4

Author(s):

E. M. Rudoy ◽

N. A. Kazarinov ◽

V. Yu. Slesarenko

Keyword(s):

Numerical Simulation ◽

Layer Structure

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Study on Explosion-Resistance of Biomimetic Layered Honeycomb Structure

Advances in Civil Engineering ◽

10.1155/2020/5356145 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Ji Li ◽

Shaoqing Shi ◽

Weiming Luo ◽

Qifan Wang

Keyword(s):

Numerical Simulation ◽

Layer Structure ◽

Sacrificial Layer ◽

Time History ◽

Single Layer ◽

Honeycomb Structure ◽

Homogenization Theory ◽

Maximum Deformation ◽

Explosion Load ◽

Bearing Layer

A new type of explosion-resistant biomimetic layered honeycomb structure was designed based on the natural mechanism and biological inspiration, which was mainly composed of a sacrificial layer and a bearing layer. The shock tube device was adopted to analyze the dynamic response of the biomimetic layered honeycomb structure under the action of explosion load in order to obtain the deformation modality, deflection data, and strain time-history curve of the structure. It turns out that the maximum deformation deflection of the back panel of the structure is only 28 mm. Compared with the structure of single-layer honeycomb, the independent sacrificial layer, and bearing layer, the biomimetic layered honeycomb structure has good explosion-resistant performance and can repeatedly bear multiple explosion loads. Besides, equivalent homogenization theory was employed to carry out numerical simulation. The results show that the numerical simulation results are perfectly in line with the results of experiments, and the numerical simulation method is proven to be feasible and effective. Under the action of explosion load, the biomimetic layered honeycomb structure absorbs energy mainly by sacrificial layers that are in layered and staggered arrangement. In addition, the sharp rangeability of the kinetic energy of bearing layer structure indicates that it has the feature of large mass, which can be used as the bearing part of the biomimetic layered honeycomb structure.

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Numerical Simulation Modelling of Building-Integrated Photovoltaic Double-Skin Facades

10.5772/intechopen.97171 ◽

2021 ◽

Author(s):

Siliang Yang ◽

Francesco Fiorito ◽

Deo Prasad ◽

Alistair Sproul

Keyword(s):

Numerical Simulation ◽

Energy Consumption ◽

Thermal Comfort ◽

Layer Structure ◽

Building Design ◽

Simulation Modelling ◽

Building Envelope ◽

Design Tool ◽

Building Integrated Photovoltaic ◽

Double Skin

Building-integrated photovoltaic (BIPV) replaces building envelope materials and provides electric power generator, which has aroused great interest for those in the fields of energy conservation and building design. Double-skin façade (DSF) has attracted significant attention over the last three decades due to its bi-layer structure, which improves thermal and acoustic insulation and therefore increases the energy efficiency and thermal comfort of buildings. It is hypothesised that the integration of BIPV and DSF (BIPV-DSF) would help buildings in reducing energy consumption and improving indoor thermal comfort concurrently. However, the prototype of the BIPV-DSF has not been well explored. Thus, the investigations of the BIPV-DSF are worthwhile. Numerical simulation is a cost and time effective measure for the design and analysis of buildings. This chapter spells out a comprehensive method of numerical simulation modelling of the novel BIPV-DSF system in buildings, which is carried out by using a graphically based design tool – TRNSYS and its plugins. TRNSYS has been validated and widely used in both the BIPV and building related research activities, which are capable in analysing the effects of BIPV-DSF on building performance such as energy consumption and indoor thermal condition.

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Numerical simulation and intercomparison of boundary layer structure with different PBL schemes in WRF using experimental observations at a tropical site

Atmospheric Research ◽

10.1016/j.atmosres.2014.03.023 ◽

2014 ◽

Vol 145-146 ◽

pp. 27-44 ◽

Cited By ~ 64

Author(s):

K.B.R.R. Hariprasad ◽

C.V. Srinivas ◽

A.Bagavath Singh ◽

S. Vijaya Bhaskara Rao ◽

R. Baskaran ◽

...

Keyword(s):

Numerical Simulation ◽

Boundary Layer ◽

Layer Structure ◽

Boundary Layer Structure

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Mechanical Analysis for Laying Thermal Insulation Pipe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.2505 ◽

2012 ◽

Vol 476-478 ◽

pp. 2505-2509

Author(s):

Jing Hao Chen ◽

Meng Lan Duan ◽

Jian Zhang

Keyword(s):

Numerical Simulation ◽

Thermal Management ◽

Thermal Insulation ◽

Deformation Theory ◽

Layer Structure ◽

Mechanical Analysis ◽

Equivalent Stiffness ◽

Complicated Structure ◽

Controlling Parameter ◽

The Common

When crude oil contains wax and hydrate depositions, thermal management is needed to built up to prevent these deposition formation. Thermal insulation pipe is the common measure. Laying thermal insulation pipe is a complex operation due to their multi-layer structure and heavier weight. In this paper, mechanical analysis for thermal insulation pipe laid by S-lay is carried out. Large deformation theory is applied to establish S-lay model. Equivalent stiffness theory is used to solve the complicated structure. Numerical simulation is done to investigate the effect of controlling parameters to the pipe configuration. Numerical results show that the tension is the main controlling parameter during pipelay.

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Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103103 ◽

1988 ◽

Vol 46 ◽

pp. 204-205

Author(s):

Kazumichi Ogura ◽

Michael M. Kersker

Keyword(s):

High Resolution ◽

Layer Structure ◽

High Sensitivity ◽

Beam Current ◽

Electron Beam Current ◽

Lattice Structures ◽

Super Lattice ◽

Different Types ◽

Backscattered Electron ◽

Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

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Generation of 4H and 6H Structures During the Hexagonal-Rhombohedral Transformation in Dy2Co17

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113810 ◽

1975 ◽

Vol 33 ◽

pp. 38-39

Author(s):

C. W. Allen ◽

D. L. Kuruzar

Keyword(s):

Elevated Temperatures ◽

Layer Structure ◽

Transition Element ◽

Temperature Structure ◽

Allotropic Transformation ◽

Layer Plane ◽

Planar Defects ◽

Topologically Close Packed ◽

Transformation Mechanisms ◽

Shear Transformation

The rare earth/transition element intermetallics R2T17 are essentially topologically close packed phases for which layer structure models have already been presented. Many of these compounds are known to undergo allotropic transformation of the type at elevated temperatures. It is not unexpected that shear transformation mechanisms are involved in view of the layering character of the structures. The transformations are evidently quite sluggish, illustrated in furnace cooled Dy2Co17 by the fact that only rarely has the low temperature rhombohedral form been seen. The more usual structures observed so far in furnace cooled alloys include 4H and 6H in Dy2Co17 (Figs. 1 and 2) . In any event it is quite clear that the general microstructure is very complicated as a consequence of the allotropy, illustrated in Fig. 3. Numerous planar defects in the layer plane orientation are evident as are non-layer plane defects inherited from a high temperature structure.

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