Astrochemistry, Supersonic Flows, and Additive Manufacturing: A Design Optimisation Framework for Laval nozzles in Uniform Supersonic Chemical Reactor

星际介质的化学动力学及其相关的天体化学对于理解在太空中观察到的分子的形成和破坏以及行星大气的组成是必不可少的。这些介质中的反应通常发生在非常低的温度环境中（低至~ 10k），在实验室条件下进行实验模拟是具有挑战性的。为此，化学家使用一种被称为拉瓦尔喷嘴的装置来产生低温，在低温下可以在流动中研究反应动力学。通过拉瓦尔喷嘴（会聚-发散段）使用脉冲超音速流（Ma高达~4）产生所需的低温。目前，这是通过实验性的Laval喷嘴几何设计来实现的，这种设计既昂贵又耗时。该项目将为这些“均匀超音速化学反应堆”（USCRs）中使用的拉瓦尔喷嘴的设计提供合理的框架。这将结合使用计算流体动力学（CFD）进行超音速流动预测，喷嘴的增材制造和天体化学实验。将实施正式的设计优化技术，以实现最佳的形状和拓扑结构，以保持必要的温度和压力条件。这一过程还将包括将增材制造的随机特性结合到框架中。

The chemical kinetics of interstellar media and its associated astrochemistry are essential in understanding the formation and destruction of molecules observed in space and the composition of planetary atmospheres. Reactions in these media often occur in very low temperature environments (down to ~10 K) which are challenging to mimic experimentally under laboratory conditions. For this purpose, chemists use an apparatus known as a Laval nozzle to generate the low temperatures under which the reaction kinetics can be studied within the flow. The necessary low temperature is generated using pulsed supersonic flow (Ma up to ~4) via a Laval nozzle (converging-diverging section). Currently this is achieved using experimentally informed designs for the Laval nozzle geometry which are expensive and time consuming. This project will deliver rational framework for the design of the Laval nozzles used in these "Uniform Supersonic Chemical Reactors" (USCRs). This will combine the use of Computational Fluid Dynamics (CFD) for supersonic flow prediction, additive manufacturing of nozzles, and astrochemical experimentation. Formal design optimisation techniques will be implemented to achieve the best possible shape and topology to maintain the necessary temperature and pressure conditions. This process will also include combining the stochastic nature of additive manufacturing into the framework.