Experimental and Numerical Study for High Energy Impact Absorption with a Composite Material in Aeronautics

2018 ◽  
pp. 64-76
Author(s):  
Bruno Derias ◽  
Pierre Spiteri ◽  
Philippe Marthon ◽  
Léon Ratsifandrihana
Keyword(s):  
Composite Material ◽  
Numerical Study ◽  
High Energy ◽  
Energy Impact ◽  
Impact Absorption

Mullite Diffusion Barriers for SiC-C/C Composites Produced by Pulsed Laser Deposition

1998 ◽  
Vol 555 ◽  
Author(s):  
H. Fritze ◽  
A. Schnittker ◽  
T. Witke ◽  
C. Rüscher ◽  
S. Weber ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Target Material ◽  
High Energy ◽  
Single Step ◽  
Laser Deposition ◽  
Reduced Pressure ◽  
Oxidation Rates ◽  
Energy Impact ◽  
Diffusion Parameters

AbstractPulsed Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 pm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.

High energy impact techniques application for surface grain refinement in AZ91D magnesium alloy

2008 ◽  
Vol 43 (13) ◽  
pp. 4658-4665 ◽  
Author(s):  
Li-feng Hou ◽  
Ying-hui Wei ◽  
Bao-sheng Liu ◽  
Bing-she Xu
Keyword(s):  
Magnesium Alloy ◽  
Grain Refinement ◽  
High Energy ◽  
Az91d Magnesium Alloy ◽  
Energy Impact

Treatment of Peaty Clay by High Energy Impact

1979 ◽  
Vol 105 (8) ◽  
pp. 957-967
Author(s):  
Salem D. Ramaswamy ◽  
Seng-Lip Lee ◽  
M.H. Abdul Khader ◽  
Raja V. Subrahmanyam ◽  
Mohamed A. Aziz
Keyword(s):  
High Energy ◽  
Energy Impact

Discussion of “Treatment of Peaty Clay by High Energy Impact”

1980 ◽  
Vol 106 (10) ◽  
pp. 1170-1171
Author(s):  
Thomas J. Kaderabek
Keyword(s):  
High Energy ◽  
Energy Impact

Numerical Study to Analyze the Effects of Hot/Cold Aisle Configurations on Heat Transfer Phenomenon in a Data Center

2013 ◽  
Author(s):  
Kamran Nazir ◽  
Naveed Durrani ◽  
Imran Akhtar ◽  
M. Saif Ullah Khalid
Keyword(s):  
Heat Transfer ◽  
Data Center ◽  
Data Centers ◽  
Cooling System ◽  
Numerical Study ◽  
High Energy ◽  
Research Area ◽  
Transfer Phenomenon ◽  
Heat Transfer Phenomenon ◽  
Active Research

Due to high energy demands of data centers and the energy crisis throughout the world, efficient heat transfer in a data center is an active research area. Until now major emphasis lies upon study of air flow rate and temperature profiles for different rack configurations and tile layouts. In current work, we consider different hot aisle (HA) and cold aisle (CA) configurations to study heat transfer phenomenon inside a data center. In raised floor data centers when rows of racks are parallel to each other, in a conventional cooling system, there are equal number of hot and cold aisles for odd number of rows of racks. For even number of rows of racks, whatever configuration of hot/cold aisles is adopted, number of cold aisles is either one greater or one less than number of hot aisles i.e. two cases are possible case A: n(CA) = n(HA) + 1 and case B: n(CA) = n(HA) − 1 where n(CA), n(HA) denotes number of cold and hot aisles respectively. We perform numerical simulations for two (case1) and four (case 2) racks data center. The assumption of constant pressure below plenum reduces the problem domain to above plenum area only. In order to see which configuration provides higher heat transfer across servers, we measure heat transfer across servers on the basis of temperature differences across racks, and in order to validate them, we find mass flow rates on rack outlet. On the basis of results obtained, we conclude that for even numbered rows of rack data center, using more cold aisles than hot aisles provide higher heat transfer across servers. These results provide guidance on the design and layout of a data center.

scholarly journals Experimental and Numerical Study on the Effect of Creep Behavior on Epoxy Composites Reinforced with Yttrium Oxide Powder

2020 ◽  
Vol 25 (4) ◽  
pp. 203-213
Author(s):  
B.H. Abed ◽  
K.J. Jadee ◽  
A.A. Battawi
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Elasticity Modulus ◽  
Epoxy Composite ◽  
Numerical Study ◽  
Creep Behaviour ◽  
Weight Ratio ◽  
Volume Ratio ◽  
Epoxy Composites ◽  
Creep Characteristics

AbstractThe creep test is one of the important approaches to determining some mechanical properties of composite materials. This study was carried out to investigate the creep behaviour of an epoxy composite material that was reinforced with Y2O3 powder at weight ratios of 2%, 7%, 12%, 17% and 22%. Each volume ratio was subjected to five loads over the range of 1N to5N at a constant temperature of 16 ± 2°C. In this work, creep behaviour, stress and elasticity modulus were studied through experimental and numerical analyses. Results showed that increasing the weight ratio of Y2O3 powder enhanced creep characteristics.

Analysis of High Energy Impact of a Raindrop on Water

2020 ◽  
pp. 907-922
Author(s):  
Mohamed Houssein Ghandour ◽  
Annie-Claude Bayeul-Lainé ◽  
Olivier Coutier-Delgosha
Keyword(s):  
High Energy ◽  
Energy Impact
Sign in / Sign up

Export Citation Format

Share Document