利用CE/SE(conservation element and solution element)格式研究了柱面会聚波在气体中传播时间断面的不稳定问题和波阵面的演变问题,并利用level set函数追踪了驱动气体与低压气体间断面的发展过程。得到了间断面的Rayleigh-Taylor(R-T...利用CE/SE(conservation element and solution element)格式研究了柱面会聚波在气体中传播时间断面的不稳定问题和波阵面的演变问题,并利用level set函数追踪了驱动气体与低压气体间断面的发展过程。得到了间断面的Rayleigh-Taylor(R-T)和Richt myer-Meshkov(R-M)不稳定性发展成典型的"尖钉"和"气泡"结构的图像,初始正弦扰动下的会聚波产生"尖角"和"尖瓣"结构。结果表明,CE/SE格式在涉及会聚波的数值计算中是可行的。展开更多
The discrete time model for a single link of Diffserv is considered in this paper. A novel algorithm is proposed to improve the robustness of the existing model. It allows the link price to fluctuate slightly around t...The discrete time model for a single link of Diffserv is considered in this paper. A novel algorithm is proposed to improve the robustness of the existing model. It allows the link price to fluctuate slightly around the equilibrium price. Simulations are performed to verify the effectiveness of the algorithm. This model solves the problem that the existing model can converge only under the strict condition.展开更多
We present computational results on the evolution of the shock-accelerated heavy bubbles surrounded by nitrogen with the Atwood number At = 0.497–0.677 and the emphasis is on the jet phenomenon caused by the shock fo...We present computational results on the evolution of the shock-accelerated heavy bubbles surrounded by nitrogen with the Atwood number At = 0.497–0.677 and the emphasis is on the jet phenomenon caused by the shock focusing. The multi-fluid Eulerian equation is solved by a finite volume method based on MUSCL-Hancock approach. Based on the numerical schlieren and the distributions of density and pressure, it is found that there are three typical jet structures(outward jet, no jet, inward jet) for different combinations of gas mixture inside the bubble which determine the position of shock focusing relative to the downstream pole of the heavy bubble(upstream of the pole, at the pole, downstream the pole). Compared with the inward jet, the velocity of outward jet is obviously larger. As At increases, the moment of jet formation is postponed, and the maximal values and magnifications of pressure and density increase distinctly. Therefore, the energy convergence effects are heavily enhanced with the increase of bubble gas density.展开更多
文摘利用CE/SE(conservation element and solution element)格式研究了柱面会聚波在气体中传播时间断面的不稳定问题和波阵面的演变问题,并利用level set函数追踪了驱动气体与低压气体间断面的发展过程。得到了间断面的Rayleigh-Taylor(R-T)和Richt myer-Meshkov(R-M)不稳定性发展成典型的"尖钉"和"气泡"结构的图像,初始正弦扰动下的会聚波产生"尖角"和"尖瓣"结构。结果表明,CE/SE格式在涉及会聚波的数值计算中是可行的。
文摘The discrete time model for a single link of Diffserv is considered in this paper. A novel algorithm is proposed to improve the robustness of the existing model. It allows the link price to fluctuate slightly around the equilibrium price. Simulations are performed to verify the effectiveness of the algorithm. This model solves the problem that the existing model can converge only under the strict condition.
基金supported by the National Natural Science Foundation of China(Grant Nos.11172278,11302201,11472253 and 11202195)Science Foundation of China Academy of Engineering Physics(Grant No.2014B0201017)
文摘We present computational results on the evolution of the shock-accelerated heavy bubbles surrounded by nitrogen with the Atwood number At = 0.497–0.677 and the emphasis is on the jet phenomenon caused by the shock focusing. The multi-fluid Eulerian equation is solved by a finite volume method based on MUSCL-Hancock approach. Based on the numerical schlieren and the distributions of density and pressure, it is found that there are three typical jet structures(outward jet, no jet, inward jet) for different combinations of gas mixture inside the bubble which determine the position of shock focusing relative to the downstream pole of the heavy bubble(upstream of the pole, at the pole, downstream the pole). Compared with the inward jet, the velocity of outward jet is obviously larger. As At increases, the moment of jet formation is postponed, and the maximal values and magnifications of pressure and density increase distinctly. Therefore, the energy convergence effects are heavily enhanced with the increase of bubble gas density.
