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

This project aims to deliver a framework for rationally designing Laval nozzles used in Uniform Supersonic Chemical Reactors to measure the chemical kinetics of interstellar media to further understand the astrochemistry of stars and planetary atmospheres (Figure 1). Underpinning this framework will be the development of a novel 3D supersonic Computational Fluid Dynamics (CFD) model which captures the pulsed flow through parameterised Laval nozzles (Figure 2). The optimiser will be capable of determining the best possible shape and topology of the nozzle which ensures a constant temperature and pressure environment within the reaction chamber, while also maintaining high flow speeds (up to Ma ~4) and low flow temperatures (down to ~25 K).

Optimised nozzle designs will be established for a range of different reaction conditions and resulting flow structures (e.g., shock formation, flow oscillation). Rapid prototyping will subsequently be implemented using additive manufacturing technologies to develop candidate nozzles for experimental testing in the reactors. A validation of the CFD model will be undertaken by comparing measurements of temperature and pressure obtained experimentally with those predicted computationally. This will also include an analysis of the stochastic nature of the additively manufactured products which introduce significant variability in terms of tolerances and surface finishing.