PurposeTandem wing aircrafts belong to an unconventional configuration. It consists of two pairs of similar wings generating lift. System is characterised by strong aerodynamic coupling between wings. The flow around this configuration is very complex and difficult to model in the CFD software. This study aims to investigate the impact of flow modelling on resulting aerodynamic coefficients. Mainly, the coefficients obtained by two different independent software were analysed. Their value and course for complete aircraft and for both wings as well. Moreover, during analysis, different positions of the rear wing were considered as well. This research seeks new insights into method of modelling the flow around aircraft in the tandem wing configuration, to find the best methodology for aerodynamic analysis of the aircraft in the tandem wing configuration.Design/methodology/approachThe methodology used in this work is focused on two advanced commercial CFD software: Ansys-Fluent (www.ansys.com/products/fluids/ansys-fluent) and MGAERO (MGAERO, 2011). The first one uses advanced RANS method. The second one uses the Euler's equations and the multigrid scheme to solve the arbitrary configuration. The computation by first method is very time-consuming and needs a lot of time to prepare the model. The second method is less time-consuming but has less accuracy. Comparison of the results obtained by both methods allows to assess the methodology impact on the aerodynamic coefficients.FindingsThis paper presents the results obtained by two independent software. Analysis reveals that similar results are obtained for lower angles of attack, but for higher angles the discrepancies arise. This is caused by unsteady effects close to the stalling which cannot be considered in MGAERO. In addition, consistency in total coefficients is not always followed by consistency for both wings separately. Above conclusions indicate that simpler software can be used for preliminary analysis of a tandem wing, but for the details of the aerodynamic coupling between the wings, a more advanced approach is necessary, despite the high computational cost.Practical implicationsObtained numerical results are necessary for further research on the tandem wing configuration, which will be focused on the wide range of wind tunnel tests.Originality/valueThis study shows the comparison of two methods of flow field modelling. This research offers a novel perspective on tandem wings' analysis, providing valuable insights that extend the current understanding of mutual aerodynamic coupling between the wings. Contrary to the most common approach, not only the impact the front wing has on the rear wing is considered, but also the opposite and that reveals the differences in modelling for different software. The study's findings highlight the areas for future research.
