Abstract The triggering combustion instability in the solid rocket motor is investigated from a nonlinear dynamical system perspective. A coupling model taking both the nonlinear acoustics in the chamber and the unsteady combustion of the solid propellant into consideration is adopted. Its typical responses to different excitations are compared systematically for varying parameters. The boundaries for the different responses in the parameter space are then investigated from the bifurcation analysis. It is shown that the triggering region of the solid rocket motor, corresponding to the bistable region of the coupling model, is confined by two curves consisting of bifurcation points, which intersects at a high order bifurcation point, the cusp point. The complex geometry of bistable region in multi-dimensional parameter space indicates the influences of parameters on the triggering combustion instability of the solid rocket motor can be quite different. The results suggest a comprehensive consideration on different parameters is needed in evaluating the combustion instability of an solid rocket motor.

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固体火箭发动机中触发燃烧不稳定性的非线性特性

摘要 从非线性动力系统的角度研究了固体火箭发动机燃烧失稳的触发问题。采用综合考虑室内非线性声学和固体推进剂非稳态燃烧的耦合模型。针对不同参数系统地比较了其对不同激励的典型响应。然后通过分岔分析研究参数空间中不同响应的边界。结果表明，固体火箭发动机的触发区域，对应于耦合模型的双稳态区域，被两条由分叉点组成的曲线限制，该曲线在高阶分叉点，即尖点处相交。多维参数空间中双稳态区域的复杂几何结构表明参数对固体火箭发动机触发燃烧不稳定性的影响可能大不相同。结果表明，在评估固体火箭发动机的燃烧不稳定性时，需要综合考虑不同的参数。