Computational study of flow over generic fan-wing airfoil

Purpose - The paper seeks to perform a detailed numerical study of flow over a generic fan-wing airfoil and also attempts to modify the geometry for the improvement of the aerodynamic performance. Design/methodology/approach - Advanced computational fluid dynamics (CFD) technique has been employed for evaluation of the aerodynamic performance (e.g. lift/drag ratio) of a model problem. Numerical investigation starts with sensitivity studies to minimize domain size influence and grid dependency, followed by time-accurate transient calculations. A preliminary re-design exercise has been performed by analyzing the results of a current design. Findings - CFD predicted lift force agrees fairly well with the measurement data with about 6.55 per cent error, while drag force compares less favourably with about 12.59 per cent error. Both errors are generally acceptable for an engineering application of complex flow problems. Several key flow features observed previously by experiment have also been re-produced by simulation, notably the eccentric vortex motions in the blade interior and the stream "jet" flow outside the blades near the exit. With the modified geometry, there is a considerable lift/drag ratio improvement of about 29.42 per cent. The possible reasons for such a significant improvement have been discussed. Research limitations/implications - As it is the first step towards thedetailed flow analysis of this type of model, a simpler blade shape rather than "real" one has been used. Practical implications - The paper provides a very useful source of information and could be used as guidance for further industry practice of unmanned aerial vehicles design. Originality/value - This paper is valuable for both academic researchers and industry engineers, especially those working in the area of high-lift wing design. The works presented are original