类蜂窝结构对腔体流动分岔的影响研究
ON THE FLOW BIFURCATIONS OF LID-DRIVEN QUASI-HONEYCOMB CAVITY FLOW
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摘要: 流动分岔对于厘清流场物理特性意义非凡, 对于工程实际中遇到的流动问题分析和相关应用有着非常重要的指导意义. 作为流体力学中的经典问题, 腔体流动在很多重要领域都被广泛应用, 具备极高的研究价值. 对于腔体内流流动而言, 腔体几何构型对于流动分岔的类型和临界雷诺数影响较大. 针对目前国内外研究现状, 部分几何构型对于流动分岔的影响规律尚未明晰. 文章通过基于直角网格的LBM算法和流场稳定性分析理论, 针对类蜂窝构型的腔体内流开展数值模拟和流动现象机理分析研究, 揭示了类蜂窝结构对于内流流场流动分岔的影响机制. 对比之前的研究, 着重探究类蜂窝构型对于Hopf、Neimark-Sacker以及Turbulence-triggering流动分岔的影响以及该构型内流动演化模式和涡系发展特征, 从物理层面分析流动现象的形成机理. 研究结果表明, 虽然类蜂窝构型不会影响流动分岔的类型以及流场演化模式, 但是对于流动分岔的临界值影响较大. 可以有效推迟流动失稳和湍流出现, 极大地提升了内流流场的稳定性. 此外, 该流场内的涡系结构及演化规律异常稳定.Abstract: The study on flow bifurcations is of great significance in clarifying the physical characteristics of the flow field, and has important guiding significance for the analysis of flow problems encountered in engineering purposes and corresponding applications. As a classic problem in fluid mechanics, cavity flows have been widely applied in many important fields and has extremely high research values. For the flow inside the cavity, the geometric configuration of the cavity has a significant impact on the types and critical Reynolds numbers of flow bifurcations. Based on the literature review worldwide, the influence of certain geometric configurations on flow bifurcation is not yet clear. As a result, we conduct numerical simulations and flow mechanism analysis on the flow inside a cavity with a quasi-honeycomb structure through the LBM algorithm based on Cartesian grid and flow field stability analysis, revealing the influence of the quasi-honeycomb structure on the flow bifurcations of this internal flow. Compared with previous research, this study is focused on exploring the influence of quasi-honeycomb configuration on the Hopf, Neimark-Sacker, and Turbulence trigging flow bifurcations, as well as the flow evolution patterns and vortex development characteristics within this configuration. The mechanism of flow phenomena is analyzed from a physical perspective. The numerical results indicate that although the quasi-honeycomb configuration does not affect the type of flow bifurcations and the evolution patterns of the flow, it has a significant influence on the critical values of flow bifurcations. It can effectively delay the occurrence of flow instability and turbulence, greatly improving the stability of this internal flow. In addition, the vortex structure and evolution behavior within the flow field are exceptionally stable.