A proposed design for a gun-launched, unmanned aerial system (GLUAS) is presented, along with experimental data pertaining to the characterization of said design, and specifically targeted towards improving its aerodynamics through an examination of planform shape and wing flexibility.
The proposed design consists of a deployable wing micro-aerial vehicle (MAV) that can fit inside of a 60mm mortar shell. The wings consist of 5individual segments on each side, which stack on top of one another within the body, and are deployed by a torsion spring and an interlocking system of gears and bosses. These wings form a roughly semi-circular planform with a slightly adjustable sweep angle.
Flight testing of the proposed design remains inconclusive, as stable flight has not yet been achieved. The current design is difficult to control due to limited control authority provided by a pair of elevons, and has not been successfully trimmed.
Wind tunnel measurements are reported for flat plates of a variety of sweep angles, in order to determine if changing the sweep angle has any significant effect on the performance of a MAV at Reynolds numbers of order 105. It is found that a sweep of 25 degrees potentially contributes to a more efficient wing, however the results are not conclusive. Further, it is shown that a 65 degree wing is conclusively inferior.
Testing also reveals that the use of plastic, in place of metal, to construct the wings could contribute to slightly higher values for the coefficient of lift,as well as range and endurance. It is also shown that the use of a highly-flexible membrane wing results in a significant improvement in the range and endurance of the test model, as well as a significant weight reduction.