GOALI: Predicting Acoustic Wave Dynamics in Solid and Hybrid Rocket Motors

该GOALI项目旨在促进对涡旋声波与流体动力不稳定性和热波耦合的基本理解，以及导致固体和混合火箭发动机中波浪陡增和极限环振荡的非线性过程。分析涉及物理建模、摄动方法和源自全球不稳定理论和廖？用S同伦方法处理非线性问题。这项工作将导致考虑气流方向性的模拟燃烧室可压缩堆芯流动模型的多维解。一个直接的例子包括气体的多向扫掠运动和推进剂表面上方和穿过表面的流动的不均匀性。作为组织，该项目建立在PI和工业赞助商的现有优势上，后者目前专注于开发最先进的混合动力发动机。鉴于混合动力汽车的声学稳定性模型还没有得到普遍认可，这项资助下提出的基础研究活动将加强工业研究者的努力，以促进清洁混合动力技术的商业化潜力。推进推进系统严格的声学稳定性理论将有助于提高现有诊断和设计能力所需的深刻科学见解。预计的增强可以对火箭和涡轮系统的未来发展产生重大影响。因此，统一的稳定性框架对移动行业的直接影响在航空航天和发电领域都是显著的。例如，了解和抑制不稳定性对于证明混合动力技术的可行性及其在太空和陆地应用中作为安全、清洁推进替代方案的应用至关重要。在教育方面，主要研究人员将结合他们在固体和混合流场建模方面的独特优势，协调各种研究人员和参与者的培训和指导。他们的努力将对社会产生直接影响，通过战略规划的课程、座谈会、研讨会和顶点设计活动，使高中、大学和研究生接触到火箭、声学噪声控制和混合动力推进领域的重要研究前景。

This GOALI project aims at advancing the fundamental understanding of vortico-acoustic wave coupling with hydrodynamic instability and thermal waves, along with the nonlinear processes leading to wave steepening and limit cycle oscillations in solid and hybrid rocket motors. The analysis involves physical modeling, perturbation methods, and concepts derived from the biglobal instability theory and Liao?s homotopy approach for the treatment of nonlinearities. The work will lead to multidimensional solutions of compressible core flow models in simulated combustors that take into account flow directionality. An immediate example includes the multidirectional sweeping motion of the gases and the non-uniformity of the flow above and across the propellant surface. As organized, this program builds on the existing strengths of the PI and an industrial sponsor who is presently focused on the development of state-of-the-art hybrid motors. Given that no universally accepted acoustic stability model exists for hybrids, the basic research activities proposed under this grant will enhance the efforts taken by the industrial investigator to promote the commercialization potential of clean hybrid technology. Advancing a rigorous acoustic stability theory for propulsive systems will aid in promoting the deep scientific insight needed to improve existing diagnostic and design capabilities. The projected enhancements can have a substantial bearing on the future development of rocket and turbine based systems. The direct impact of a unifying stability framework on the mobility industry can thus be significant in both aerospace and power generation categories. For example, understanding and suppressing instability can critically aid in demonstrating the viability of hybrid technology and its use as a safe and clean propulsion alternative in both space and land applications. On the educational side, the principal investigators will combine their unique strengths in solid and hybrid flow field modeling to coordinate the training and mentoring of various researchers and participants. Their efforts will have a direct impact on society by exposing high school, college, and graduate students to vital research prospects in rocketry, acoustic noise control, and hybrid propulsion through strategically planned courses, colloquia, workshops, and capstone design activities.