Design of the Subsonic Aircraft Roughness Glove Experiment (SARGE)

Abstract

The Subsonic Aircraft Roughness Glove Experiment (SARGE) is a hybrid natural laminar flow and passive laminar flow control flight test that will be carried out under the auspices of the NASA Environmentally Responsible Aviation initiative. Texas A&M has completed the initial aerodynamic design of a wing glove to be installed on a NASA Gulfstream III testbed. The primary goals of the SARGE experiment are to 1) achieve natural laminar flow to 0.60 chord on the suction side at up to 22 million chord Reynolds number and 2) at conditions of at least 22 million chord Reynolds number, demonstrate the effectiveness of passive Discrete Roughness Elements in extending laminar flow beyond the natural transition location. Computations of the flight test configuration flowfield and the initial design of a laminar flow wing glove are presented, followed by a description of the proposed flight test experiment as well as the instrumentation suite. The initial design is shown to marginally fulfill the design requirements. Efforts are underway to optimize the design to improve spanwise flow uniformity and provide better stabilization of streamwise instabilities.