Finite Mach number spherical shock wave, application to shock ignition
Finite Mach number spherical shock wave, application to shock ignition
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有限马赫数球形冲击波，在冲击点火中的应用
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
V. Tikhonchuk
中科院分区：
文献类型：
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作者：
A. Vallet;X. Ribeyre;V. Tikhonchuk
一个收敛和发散的球形激波具有有限的初始马赫数Ms0，用微扰方法在一个小参数Ms−2上描述。零阶解是Guderley的自相似解。该解的一阶修正考虑了冲击强度的影响。而在Guderley渐近解中它是恒定的，有限振幅冲击的放大因子Λ(t)∝dUs/dRs现在随时间变化。以级数形式出现的系数是迭代计算的，因此，除了激波的位置外，解不会经历任何奇异行为。在奇点附近的修正解的解析形式提供了对有限激波马赫数效应的更好的物理理解。修正主要影响激波反弹后的流量密度和压力。通过对激波点火方案的应用表明，当燃油质量达到一定水平时，点火判据的修正幅度可达20%以上。
A converging and diverging spherical shock wave with a finite initial Mach number Ms0 is described by using a perturbative approach over a small parameter Ms−2. The zeroth order solution is the Guderley's self-similar solution. The first order correction to this solution accounts for the effects of the shock strength. Whereas it was constant in the Guderley's asymptotic solution, the amplification factor of the finite amplitude shock Λ(t)∝dUs/dRs now varies in time. The coefficients present in its series form are iteratively calculated so that the solution does not undergo any singular behavior apart from the position of the shock. The analytical form of the corrected solution in the vicinity of singular points provides a better physical understanding of the finite shock Mach number effects. The correction affects mainly the flow density and the pressure after the shock rebound. In application to the shock ignition scheme, it is shown that the ignition criterion is modified by more than 20% if the fuel pr...