Pulsed Laser Energy Deposition in Supersonic Flow Over a Cylinder

2022 ◽  
Author(s):  
Shankar Ghosh ◽  
Anurag Chauhan ◽  
Rohan Pattankar
AIAA Journal ◽  
2005 ◽  
Vol 43 (2) ◽  
pp. 256-269 ◽  
Author(s):  
Russell G. Adelgren ◽  
Hong Yan ◽  
Gregory S. Elliott ◽  
Doyle D. Knight ◽  
Thomas J. Beutner ◽  
...  

2020 ◽  
Vol 53 (26) ◽  
pp. 265201 ◽  
Author(s):  
Rajib Mahamud ◽  
Daniel W Hartman ◽  
Albina A Tropina

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3914
Author(s):  
Seihwan Kim ◽  
Hyoung Jin Lee

In the present study, a two-dimensional axisymmetry unsteady numerical simulation that implements high-frequency laser energy deposition was performed to understand its influence on drag reduction in supersonic flow. The energy deposition was modeled as the increase of the temperature inside the focal region. The drag reduction characteristics were investigated by changing the frequency of the deposition, the distance between the focus of the deposition and the body, and the power of the laser. The results showed that drag could be reduced by 60% when there was a single energy deposition. As the operating frequency increased, up to 70% drag reduction was obtained. When the laser energy was deposed more frequently than 75 kHz, the normalized drag converged regardless of the deposition scenario, which resulted from the multiple interactions between the blast wave and the reflected shock. A similar tendency was found from the results of various focal distances. According to the results of this study on the effect of the deposition energy, it is expected to achieve the same effect as with low energy by increasing the frequency of the deposition.


1993 ◽  
Vol 136 (1) ◽  
pp. 107-111
Author(s):  
N. G. Chechenin ◽  
A. V. Chernysh ◽  
V. V. Korneev ◽  
E. V. Monakhov ◽  
B. V. Seleznev

1995 ◽  
Vol 395 ◽  
Author(s):  
R.D. Vispute ◽  
H. Wu ◽  
K. Jagannadham ◽  
J. Narayan

ABSTRACTAIN thin films have been grown epitaxially on Si(111) and Al2O3(0001) substrates by pulsed laser deposition. These films were characterized by FTIR and UV-Visible, x-ray diffraction, high resolution transmission electron and scanning electron microscopy, and electrical resistivity. The films deposited on silicon and sapphire at 750-800°C and laser energy density of ∼ 2 to 3J/cm2 are epitaxial with an orientational relationship of AIN[0001]║ Si[111], AIN[2 110]║Si[011] and AlN[0001]║Al2O3[0001], AIN[1 2 1 0]║ Al2O3[0110] and AIN[1010] ║ Al2O3[2110]. The both AIN/Si and AIN/Al2O3 interfaces were found to be quite sharp without any indication of interfacial reactions. The absorption edge measured by UV-Visible spectroscopy for the epitaxial AIN film grown on sapphire was sharp and the band gap was found to be 6.1eV. The electrical resistivity of the films was about 5-6×l013Ω-cm with a breakdown field of 5×106V/cm. We also found that the films deposited at higher laser energy densities ≥10J/cm2 and lower temperatures ≤650°C were nitrogen deficient and containing free metallic aluminum which degrade the microstructural, electrical and optical properties of the AIN films


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