Analysis of a Generic T-Tail Transport Using a Surface-Vorticity Panel Method Flow Solver at Low Angles of Attack

A panel method flow solver with viscous capabilities was used to determine stability characteristics, including dynamic stability derivatives, of a well-studied generic T-tail (GTT) transport aircraft model. Longitudinal, lateral, and directional static characteristics were computed using the steady and pseudo-steady state solver modes within the FlightStream panel method flow solver. The effects of control surface deflections were also investigated. Dynamic stability derivatives were computed using the pseudo-steady state and unsteady state solver modes. The results of each solver mode were compared in accuracy. The unsteady solver results were computed using the forced oscillation (F-O) method and post-processed using an integration method. All results were compared against published experimental and CFD data. Across all cases studied, the panel method results aligned well with wind tunnel data. Both solver modes used for dynamic derivative computations agree with published data in sign and relative magnitude. The solver did not correctly capture the same trends seen in experimental data in every case, but the data support the use of the tool as a rapid preliminary design and analysis tool for approximate results. The effects of using varying total amounts of forced oscillation cycles on the unsteady solver precision were also studied, with the results showing that the unsteady solver produced similar data at all numbers of cycles used with the forced oscillation method. The advantages of using the solver in finding dynamic stability parameters include low computational cost, significantly reduced computation times, and the requirement of only surface meshes. The solver showed promising capabilities in rapidly calculating a wide range of aerodynamic characteristics, supporting its use in the preliminary design process.