An artificial compressibility method for axisymmetric swirling flowsAn artificial compressibility method for axisymmetric swirling flows Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2022-11-102021enThis research has been financially supported by the Sectoral Operational Programme “Human Resources Development, Education and Lifelong Learning, NSRF 2014–2020” (Code MIS: 5047362).Purpose This study aims to feature the application of the artificial compressibility method (ACM) for the numerical prediction of two-dimensional (2D) axisymmetric swirling flows. Design/methodology/approach The respective academic numerical solver, named IGal2D, is based on the axisymmetric Reynolds-averaged Navier–Stokes (RANS) equations, arranged in a pseudo-Cartesian form, enhanced by the addition of the circumferential momentum equation. Discretization of spatial derivative terms within the governing equations is performed via unstructured 2D grid layouts, with a node-centered finite-volume scheme. For the evaluation of inviscid fluxes, the upwind Roe’s approximate Riemann solver is applied, coupled with a higher-order accurate spatial reconstruction, whereas an element-based approach is used for the calculation of gradients required for the viscous ones. Time integration is succeeded through a second-order accurate four-stage Runge-Kutta method, adopting additionally a local time-stepping technique. Further acceleration, in terms of computational time, is achieved by using an agglomeration multigrid scheme, incorporating the full approximation scheme in a V-cycle process, within an efficient edge-based data structure. Findings A detailed validation of the proposed numerical methodology is performed by encountering both inviscid and viscous (laminar and turbulent) swirling flows with axial symmetry. IGal2D is compared against the commercial software ANSYS fluent – by using appropriate metrics and characteristic flow quantities – but also against experimental measurements, confirming the proposed methodology’s potential to predict such flows in terms of accuracy. Originality/value This study provides a robust methodology for the accurate prediction of swirling flows by combining the axisymmetric RANS equations with ACM. In addition, a detailed description of the convective flux Jacobian is provided, filling a respective gap in research literature.http://creativecommons.org/licenses/by/4.0/Engineering Computations38103732–3767 Leloudas Stavros Λελουδας Σταυρος Lygidakis Georgios Λυγιδακης Γεωργιος Delis Anargyros Δελης Αναργυρος Nikolos Ioannis Νικολος Ιωαννης Emerald Artificial compressibility Agglomeration multigrid scheme Axisymmetric Navier-Stokes equations Node-centered finite-volume method Swirling flow