Selection of Tubular Reactor Configurations for a Confined Space: Analysis of Space-Fillingness and Performance

Introducing bends or coiling in a tubular reactor promotes Dean vortices, which enhance radial mixing as well as heat and mass transfer. Exploring compact geometries that strengthen curvature-induced mixing is highly beneficial for continuous flow synthesis across scales. Despite their advantages, selecting an appropriate configuration of tubular reactors in a given space (jacket) requires careful evaluation of multiple factors, including energy efficiency, dispersion behavior, heat transfer performance, and spatial compactness. This paper presents a holistic framework for selecting an optimal configuration of a tubular reactor within a confinement (jacket) based on energy efficiency, dispersion behavior, heat transfer, and spatial compactness. Ten distinct configurations are explored based on geometrical characterization and single-phase Computational Fluid Dynamics (CFD) simulations. Each configuration is evaluated for flow patterns, pressure drop, residence time distribution (RTD), and jacket-side flow distribution. The results demonstrate that geometric design, especially the number and arrangement of bends, has a pronounced impact on reactor performance, influencing both compactness and dispersion characteristics. A combined qualitative–quantitative assessment is employed, utilizing radar plots (which capture key simulation and geometric data) and a K-means clustering unsupervised learning algorithm, along with a derived performance index (Π), to rank configurations based on their geometric attributes. This approach forms a robust basis for selection and design guidance. The study indicates that while individual designs offer specific advantages, coil geometries such as multihelix, spiral, and elongated spirals deliver optimal overall performance.