A planar problem involving the impact of a solid body onto a thin membrane lying on a half-space of compressible liquid

1991 ◽  
Vol 27 (4) ◽  
pp. 361-368
Author(s):  
V. D. Kubenko ◽  
V. V. Gavrilenko
Keyword(s):  
Half Space ◽  
Solid Body ◽  
Compressible Liquid ◽  
Planar Problem ◽  
Thin Membrane ◽  
The Impact

Planar problem of the impact of a shell on an elastic half-space

1995 ◽  
Vol 31 (6) ◽  
pp. 483-490 ◽  
Author(s):  
V. D. Kubenko ◽  
V. R. Bogdanov
Keyword(s):  
Half Space ◽  
Elastic Half Space ◽  
Planar Problem ◽  
The Impact

The efficiency of application of virtual cross-sections method and hypotheses MELS in problems of wave signal propagation in elastic waveguides with rough surfaces

2016 ◽  
pp. 3564-3575 ◽  
Author(s):  
Ara Sergey Avetisyan
Keyword(s):  
Half Space ◽  
Cross Sections ◽  
Classical Method ◽  
Signal Propagation ◽  
Elastic Half Space ◽  
Layered Systems ◽  
Surface Layers ◽  
Inhomogeneous Surface ◽  
Wave Signal ◽  
The Impact

The efficiency of virtual cross sections method and MELS (Magneto Elastic Layered Systems) hypotheses application is shown on model problem about distribution of wave field in thin surface layers of waveguide when plane wave signal is propagating in it. The impact of surface non-smoothness on characteristics of propagation of high-frequency horizontally polarized wave signal in isotropic elastic half-space is studied. It is shown that the non-smoothness leads to strong distortion of the wave signal over the waveguide thickness and along wave signal propagation direction as well.  Numerical comparative analysis of change in amplitude and phase characteristics of obtained wave fields against roughness of weakly inhomogeneous surface of homogeneous elastic half-space surface is done by classical method and by proposed approach for different kind of non-smoothness.

Evaluation the effect of the ambient temperature on the liquid petroleum gas transportation pipeline

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ammar Ali Abd ◽  
Samah Zaki Naji ◽  
Ching Thian Tye ◽  
Mohd Roslee Othman
Keyword(s):  
Energy Consumption ◽  
Greenhouse Gases ◽  
Ambient Temperature ◽  
Phase Change ◽  
Liquid State ◽  
Pump Energy ◽  
Compressible Liquid ◽  
Liquefied Petroleum Gas ◽  
Efficient Design ◽  
The Impact

Abstract Liquefied petroleum gas (LPG) plays a major role in worldwide energy consumption as a clean source of energy with low greenhouse gases emission. LPG transportation is exhibited through networks of pipelines, maritime, and tracks. LPG transmission using pipeline is environmentally friendly owing to the low greenhouse gases emission and low energy requirements. This work is a comprehensive evaluation of transportation petroleum gas in liquid state and compressible liquid state concerning LPG density, temperature and pressure, flow velocity, and pump energy consumption under the impact of different ambient temperatures. Inevitably, the pipeline surface exchanges heat between LPG and surrounding soil owing to the temperature difference and change in elevation. To prevent phase change, it is important to pay attention for several parameters such as ambient temperature, thermal conductivity of pipeline materials, soil type, and change in elevation for safe, reliable, and economic transportation. Transporting LPG at high pressure requests smaller pipeline size and consumes less energy for pumps due to its higher density. Also, LPG transportation under moderate or low pressure is more likely exposed to phase change, thus more thermal insulation and pressure boosting stations required to maintain the phase envelope. The models developed in this work aim to advance the existing knowledge and serve as a guide for efficient design by underling the importance of the mentioned parameters.

Comparison of Cooling Film Development Calculations for Transpiration Cooled Flat Plates With Different Turbulence Models

2001 ◽  
Author(s):  
Dieter E. Bohn ◽  
Norbert Moritz
Keyword(s):  
Fluid Flow ◽  
Thermal Barrier Coating ◽  
Solid Body ◽  
Turbulence Models ◽  
Thermal Barrier ◽  
Flat Plates ◽  
Jet Mixing ◽  
Barrier Coating ◽  
Film Development ◽  
The Impact

A transpiration cooled flat plate configuration is investigated numerically by application of a 3-D conjugate fluid flow and heat transfer solver, CHT-Flow. The geometrical setup and the fluid flow conditions are derived from modern gas turbine combustion chambers. The plate is composed of three layers, a substrate layer (CMSX-4) with a thickness of 2 mm, a bondcoat (MCrAlY) with thickness 0,15 mm, and a thermal barrier coating (EB-PVD, Yttrium stabilized ZrO2) with thickness 0,25 mm, respectively. The numerical grid contains the coolant supply (plenum), the solid body, and the main flow area upon the plate. The transpiration cooling is realized by finest drilled holes with a diameter of 0,2 mm that are shaped in the region of the thermal barrier coating. The holes are inclined with an angle of 30°. Two different configurations are investigated that differ in the shaping of the holes in their outlet region. The numerical investigation focus on the influence of different turbulence models on the results. Regarding the secondary flow, the cooling film development and complex jet mixing vortex systems are analyzed. Additionally, the impact on the temperature distribution both on the plate surface and in the plate is investigated. It is shown that the choice of the turbulence model has a significant influence on the prediction of the flow structure, and, consequently, on the calculation of the thermal load of the solid body.

Bubble behaviour in a horizontal high-speed solid-body rotating flow

2021 ◽  
Vol 925 ◽  
Author(s):  
Majid Rodgar ◽  
Hélène Scolan ◽  
Jean-Louis Marié ◽  
Delphine Doppler ◽  
Jean-Philippe Matas
Keyword(s):  
Aspect Ratio ◽  
Solid Body ◽  
High Speed ◽  
Lift Coefficient ◽  
Rotating Flow ◽  
Axis Of Rotation ◽  
Large Fluctuations ◽  
The Mean ◽  
Drag And Lift ◽  
The Impact

We study experimentally the behaviour of a bubble injected into a horizontal liquid solid-body rotating flow, in a range of rotational velocities where the bubble is close to the axis of rotation. We first study the stretching of the bubble as a function of its size and of the rotation of the cell. We show that the bubble aspect ratio can be predicted as a function of the bubble Weber number by the model of Rosenthal (J. Fluid Mech., vol. 12, 1962, 358–366) provided an appropriate correction due to the impact of buoyancy is included. We next deduce the drag and lift coefficients from the mean bubble position. For large bubbles straddling the axis of rotation, we show that the drag coefficient $C_D$ is solely dependent on the Rossby number $Ro$, with $C_D \approx 1.5/Ro$. In the same limit of large bubbles, we show that the lift coefficient $C_L$ is controlled by the shear Reynolds number $Re_{shear}$ at the scale of the bubble. For $Re_{shear}$ larger than 3000 we observe a sharp transition, wherein large fluctuations in the bubble aspect ratio and mean position occur, and can lead to the break-up of the bubble. We interpret this regime as a resonance between the periodic forcing of the rotating cell and the eigenmodes of the stretched bubble.

Application of an Improved Ghost Fluid Method to the Collapse of Non-Spherical Bubbles in a Compressible Liquid

2011 ◽  
Author(s):  
Hiroyuki Takahira ◽  
Yoshinori Jinbo
Keyword(s):  
Surface Tension ◽  
Shock Waves ◽  
Thermal Diffusion ◽  
Level Set ◽  
Compressible Liquid ◽  
Maximum Temperature ◽  
Bubble Collapse ◽  
Ghost Fluid Method ◽  
Toroidal Bubble ◽  
The Impact

The ghost fluid method (GFM) is improved to investigate violent bubble collapse in a compressible liquid, in which the adaptive mesh refinement with multigrids, the surface tension, and the thermal diffusion through the bubble interface are taken into account. The improved multigrid GFM is applied to the interaction of an incident shock wave with a bubble. The multigrid GFM captures the fine interfacial and vortex structures of the toroidal bubble when the bubble collapses violently accompanied with the penetration of the liquid jet and the formation of the shock waves. The multigrid GFM is also applied to the bubble collapse near a tissue surface in which the tissue is modeled with gelatin in order to predict the tissue damage due to the bubble collapse; the motions of three phases for the gas inside the bubble, the liquid surrounding the bubble, and the gelatin boundary are solved directly by coupling the level set method with the improved GFM. Two kinds of level set functions are utilized for distinguishing the gas-liquid interface from the liquid-gelatin interface. It is shown that the impact of the shock waves generated from the collapsing bubble on the boundary leads to the formation of depression of the boundary; the toroidal bubble penetrates into the depression. Also, the surface tension effects are successfully included in the improved GFM. The thermal effects of internal gas on the bubble collapse are also discussed by considering the thermal diffusion across the interface in the GFM. The thermal boundary layers of the toroidal bubble are captured with the method. The result shows that the smaller the initial bubble radius becomes, the lower the maximum temperature inside the bubble becomes because of the thermal diffusion across the interface.

Abnormal Structural Strength of Topocomposites

2012 ◽  
Vol 560-561 ◽  
pp. 338-343 ◽  
Author(s):  
Nikolay A. Voronin
Keyword(s):  
Surface Layer ◽  
Bearing Capacity ◽  
Half Space ◽  
Contact Interaction ◽  
Solid Body ◽  
Mechanical Characteristics ◽  
Structural Strength ◽  
Layered Material ◽  
Thin Surface Layer ◽  
Layer Coating

The mechanics of contact interaction of rigid spherical indenter with two-layer elastic - plastic half-space, simulating a surface of a solid body with a thin surface layer is considered. Analytical dependences of critical indentation and bearing capacity on mechanical characteristics of materials of a base and a coating, and as well as that for thickness of top layer (coating) in all region of possible thickness are received and analyzed. Existence of regions of the abnormal structural strength allowing the surface layered material to identify unequivocally as a topocomposite is shown. Theoretical dependences were verified by a final elements method.

Nonstationary contact problem for a solid body in an elastic half-space

1984 ◽  
Vol 20 (6) ◽  
pp. 425-429
Author(s):  
N. A. Lavrov ◽  
L. I. Slepyan
Keyword(s):  
Contact Problem ◽  
Half Space ◽  
Solid Body ◽  
Elastic Half Space
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