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 aerodynamic coefficients and dynamic stability derivatives of a well-studied generic T-tail (GTT) transport aircraft model. Dynamic stability derivatives were computed using two different solver modes within the FlightStream® panel method flow solver, the pseudo-steady state and unsteady state solvers. The unsteady solver results were computed using the forced oscillation (F-O) method and post-processed using an integration method. Solver results were compared with experimental data and USM3D flow solver data. Both solver modes agree with published data in sign and relative magnitude. The pseudo-steady state solver performed similarly to the USM3D flow solver in certain cases. 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 1, 2, and 3 total 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 main disadvantage is a trade-off in accuracy for the faster solver. Future work should focus on the ability of the solver to handle control surface deflection within the pseudo-steady and unsteady state solver modes. The solver showed promising capabilities in rapidly calculating approximate dynamic stability derivatives, supporting its use in the preliminary design process.