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。在这些介质中的反应通常发生在极低的温度环境中(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，化学家使用一种称为拉瓦尔喷嘴的设备来产生低温，在低温下可以研究流动中的反应动力学。所需的低温是通过拉瓦尔喷管(收敛-发散段)使用脉冲超音速流动(mA至~4)产生的。目前，这是使用拉瓦尔喷嘴几何形状的经验设计来实现的，这是昂贵和耗时的。该项目将为这些“均匀超音速化学反应器”(USCR)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、喷嘴的添加剂制造和天体化学实验。将采用正式的设计优化技术，以实现尽可能最佳的形状和拓扑结构，以保持必要的温度和压力条件。这一进程还将包括将加法制造的随机性纳入框架。

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.