Two-dimensional numerical simulation on galloping detonation in a narrow channel

2013 ◽  
Vol 34 (2) ◽  
pp. 1999-2007 ◽  
Author(s):  
Nobuyuki Tsuboi ◽  
Youhi Morii ◽  
A. Koichi Hayashi
Author(s):  
Ying Huang ◽  
Puzhen Gao

A numerical investigation of two-dimensional air bubble behaviors under the effect of gravity in still water based on the VOF (Volume-Of-Fluid) method is carried out. Initially, the surface tension effects on the behavior of the bubble is analyzed, which contains the simulation of the ascending motion of a single air bubble in liquid and the study of the interaction between bubbles in terms of coalescence. Additionally, the differences of single bubble’s rising motion in an infinite surroundings and in a vertical narrow channel are analyzed. The coalescence of bubbles is also studied. The motion of bubbles with different diameters in a vertical channel is simulated. It is found that the bubbles’ behavior depends on the distance between the bubble and the wall. Finally, numerical simulation of the motion of several bubbles of the same size, at the same initial horizontal position and with uniform distribution is carried out. The result reveals that the bubbles at different distances from the wall have different velocities, after a while, the bubbles distribution presents as “U”.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3553
Author(s):  
Dengwang Wang ◽  
Yong Gao ◽  
Sheng Wang ◽  
Jie Wang ◽  
Haipeng Li

Carbon/Phenolic (C/P), a typical anisotropic material, is an important component of aerospace and often used to protect the thermodynamic effects of strong X-ray radiation. In this paper, we establish the anisotropic elastic-plastic constitutive model, which is embedded in the in-house code “RAMA” to simulate a two-dimensional thermal shock wave induced by X-ray. Then, we compare the numerical simulation results with the thermal shock wave stress generated by the same strong current electron beam via experiment to verify the correctness of the numerical simulation. Subsequently, we discuss and analyze the rules of thermal shock wave propagation in C/P material by further numerical simulation. The results reveal that the thermal shock wave represents different shapes and mechanisms by the radiation of 1 keV and 3 keV X-rays. The vaporization recoil phenomenon appears as a compression wave under 1 keV X-ray irradiation, and X-ray penetration is caused by thermal deformation under 3 keV X-ray irradiation. The thermal shock wave propagation exhibits two-dimensional characteristics, the energy deposition of 1 keV and 3 keV both decays exponentially, the energy deposition of 1 keV-peak soft X-ray is high, and the deposition depth is shallow, while the energy deposition of 3 keV-peak hard X-ray is low, and the deposition depth is deep. RAMA can successfully realize two-dimensional orthotropic elastoplastic constitutive relation, the corresponding program was designed and checked, and the calculation results for inspection are consistent with the theory. This study has great significance in the evaluation of anisotropic material protection under the radiation of intense X-rays.


2021 ◽  
Vol 60 (2) ◽  
pp. 2629-2639
Author(s):  
Yin Yang ◽  
Grzegorz Rządkowski ◽  
Atena Pasban ◽  
Emran Tohidi ◽  
Stanford Shateyi

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