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1.
选择绕圆柱预混燃烧算例,验证CH4/空气三种简化动力学机理(16s41r、15s19r和53s325r).考虑均匀来流,忽略湍流和湍流与燃烧相互作用以及燃料扩散效应,假设层流有限反应速率,采用保自由流5阶WENO格式求解多组分Euler方程组,得到CH4/空气预混燃烧流场温度等值线、沿驻点线压力和温度及其CH4、CO和CO2质量百分数分布.结果表明:三种简化动力学机理给出的流场均出现弓形激波和火焰面,弓形激波和火焰驻点距离及其形状、诱导区宽度和简化动力学机理相关.当圆柱直径增大,弓形激波和火焰向圆柱上游移动,对应的驻点距离均增大,诱导区宽度变短,点火延时变小,但火焰和弓形激波位置次序未变化.53s325r模型要比16s41r模型和15s19r模型精度要高,点火延时覆盖的压力和温度范围也较宽,所有简化机理均未完全反应,在较大圆柱直径下游达到化学平衡. 相似文献
2.
设计了超声速钻地结构弹,采用203 mm口径的火炮,开展了25 kg量级弹体在1100~1300 m/s速度范围内侵彻钢筋混凝土靶的实验研究,应用数值仿真对弹体侵彻钢筋混凝土靶的过程进行了模拟计算。基于实验和仿真结果,对超声速侵彻条件下两种金属材料弹体的结构响应、质量损失等问题进行了分析。结果表明:在超声速侵彻钢筋混凝土靶的过程中,两种金属材料的弹体结构变形破坏形式主要为头部侵蚀和侧壁磨蚀,头部侵蚀量的大小与弹体壳体材料有关,高强度G50钢材料更适合用于1200 m/s速度量级的超声速侵彻环境。对出现的“径缩”现象作了初步分析,并对今后工程应用的结构弹体设计提出了指导意见。 相似文献
3.
4.
In this paper, a second-order implicit-explicit upwind algorithm has been developed for three-dimensional Parabolized Navier-Stokes
(PNS) equations. The agreement between the results of the new upwind algorithm and those of the implicit upwind algorithm
and its ability in marching a long distance along the streamwise direction have been shown for the supersonic viscous flow
past a sphere-cone body. The CPU time is greatly reduced.
The project supported by the National Natural Science Foundation of China 相似文献
5.
M. Yu. Plotnikov A. K. Rebrov 《Journal of Applied Mechanics and Technical Physics》2005,46(5):658-663
A supersonic flow of a binary mixture of gases in a wide range of rarefaction (from a flow with a Knudsen number K
n
= 0.1 to a free-molecular flow) around a cylinder is studied by means of direct statistical Monte Carlo simulations (DSMC method). The influence of a small fraction of heavy particles in a light gas flow on the region of significant nonequilibrium near the cylinder and on the heat flux is considered.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 53–59, September–October, 2005. 相似文献
6.
Theodore Yao-tsu Wu 《Acta Mechanica Sinica》1995,11(4):289-306
The bidirectional long-wave model introduced by Wu (1994)[1] and Yih & Wu (1995)[2] is applied to evaluate interactions between multiple solitary waves progressing in both directions in a uniform channel of
rectangular cross-section and undergoing collisions of two classes, one being head-on and the other overtaking collisions
between these solitons. For a binary head-on collision, the two interacting solitary waves are shown to merge during a phase-locking
period from which they reemerge separated, each asymptotically recovering its own initial identity while both being retarded
in phase from their original pathlines. For a binary overtaking collision between a soliton of height α1 overtaking a weaker one of height α1, the two solition peaks are shown to either pass through each other or remain separated throughout the encounter according
as α1/α2 or <3, respectively. With no phase locking during the overtaking, the two solitary waves re-emerge afterwards with their
initial forms recovered and with the stronger wave being advanced whereas the weaker one retarded in phase from their original
pathlines. By extension, the theory is generalized to apply to uniform channels of arbitrary cross-sectional shape.
The Inaugural Pei-Yuan Chou Memorial Lecture, presented at The Sixth Asian Congress of Fluid Mechanics. Singapore, 21–26 May
1995 相似文献
7.
V. N. Zaikovskii S. P. Kiselev V. P. Kiselev 《Journal of Applied Mechanics and Technical Physics》2005,46(5):670-676
Large-scale streamwise vortices in the vicinity of a perforated wall in the supersonic part of the nozzle are studied. The governing effect of gas inflow through a perforated wall on origination and parameters of streamwise vortices is experimentally established.__________Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 5, pp. 68–75, September–October, 2005. 相似文献
8.
The results of numerical integration of the Euler equations governing two-dimensional and axisymmetric flows of an ideal (inviscid and non-heat-conducting) gas with local supersonic zones are presented. The subject of the study is the formation of shocks closing local supersonic zones. The flow in the vicinity of the initial point of the closing shock is calculated on embedded, successively refined grids with an accuracy much greater than that previously achieved. The calculations performed, together with the analysis of certain controversial issues, leave no doubt that it is the intersection of C ?-characteristics proceeding from the sonic line inside the supersonic zone that is responsible for the closing shock formation. 相似文献
9.
The flow with a free-stream Mach number M
∞ = 6 around a cylindrical body with a sharp spike is studied. The existence of a supersonic reverse flow for one of the phases
of the pulsating flow regime is experimentally validated. A range of spike lengths is determined, which ensures a region of
a supersonic reverse flow near the side surface of the spike. The time of existence of the supersonic reverse flow region
is shown to be 0.15 of the period of pulsations if the spike length equals the model diameter.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 4, pp. 30–39, July–August, 2007. 相似文献
10.
超声速燃烧火焰稳定凹腔质量交换特性的数值研究 总被引:2,自引:0,他引:2
对超声速冷流条件下用于超燃冲压发动机的凹腔火焰稳定器的质量交换特性进行研
究. 采用混合RANS/LES方法对非定常流场进行数值模拟,考虑了凹腔的长深比和后缘角度两
个关键参数. 计算得到了凹腔剪切层拟序结构的演化过程. 对凹腔压力振荡历程进行幅频分
析,所得到的频率和理论分析结果及一些计算结果十分吻合. 结果表明,凹腔的长深比和后
缘倾角对凹腔质量交换过程都有较大的影响. 凹腔驻留时间随着长深比的增加而增加. 随着
后缘倾角减小,长深比较小的凹腔的驻留时间增加,长深比较大的凹腔则完全相反. 该计算
结果为凹腔设计提供了新认识. 相似文献