Validation of the aerodynamic loading on basic flying disc geometries derived from CFD simulations

The present study in spin stabilised disc aerodynamics builds on previous experimental wind tunnel work to broaden the knowledge base through CFD simulation without the necessity for high facility or time cost. The current experimental database from previous studies is extensive enough for sufficient validation to be conducted on known geometries. From there, the limitations of CFD studies for this application on such complex highly separated bluff body flows can be understood. All of the results are for non-spinning discs to reduce computational time, this step is justifiable as the spinning case has previously been shown to have minimal effect on the aerodynamic loads at typical throw release spin rates. The work builds CFD simulation cases carefully and systematically starting with cylindrical discs with thickness to chord (diameter) ratio of 0.01 and 0.1, then to introduce a cavity to one flat side analogous to the Frisbee disc, before moving to look at a generic discus geometry from field athletics. The aerodynamic loading results compare very well to experimental data for the low angle of attack range, however, at higher angles of attack the CFD curves are divergent. It is possible that the generated mesh, for each geometry, does not capture the wake with enough resolution at high angles of attack, note that for sports disc applications the high angle of attack range is very important towards the end of the flight from a human throw. Therefore, further investigations are required to extend this initial study to a modified meshing regime with further refinement, prior to moving forward with any parametric design studies. Keyword - Spin-stabilised; sports disc; discwing; gyroscopic; aerodynamics; cfd