Alvaro Toledano Escalona

Bio: Alvaro Toledano Escalona is an academic researcher. The author has contributed to research in topics: Wind tunnel & Computational fluid dynamics. The author has co-authored 1 publications.

Improvement of subsonic wall corrections in an industrial wind tunnel

Abstract: The National Research Council 5ft Trisonic Wind Tunnel enables testing of half-span models at a high Reynolds number cost effectively, however there is the possibility of experiencing relatively larger wall-interference effects compared to full span tests. Subsonic wall-interference effects due to the partially open boundaries at the NRC 5ft wind tunnel are corrected by the “one-variable” method, resulting in corrections in Mach number and angle of attack for the measured quantities. This dissertation introduces the need for adequately correcting for wall interference in subsonic half-model wind-tunnel testing in both pre-stall and post-stall conditions. The one-variable method is described and several aspects that require validation and improvement in this method are pointed out based on specific experimental and numerical results obtained for different test articles. An initial assessment of the influence of the different possible tunnel configurations and computational parameters is defined based on experimental data from a test performed on a scaled model of the Bombardier Global 6000 business jet. This initial study unveils some of the weaknesses of the one-variable method. While this method provides accurate wall corrections during tests in pre-stall conditions; it is unable to generate reliable corrections in stall. Partially, this is due to the development of flow separation on a model tested at subsonic flow conditions reaching stall, not currently accounted for by the potential theory model representation used by the wall-correction methodology at the NRC 5ft TWT. Possible improvements to this singularity representation, paramount to the one-variable method, are then investigated. This revision of the model representation is based on high fidelity free-air CFD solutions for the NASA Common Research Model, validated by experimental data sets obtained from a semispan version of the CRM tested at the NRC 5ft Trisonic Wind Tunnel. The improved potential representation is tested on solid-wall experimental wind-tunnel data to present more reliable behavior of the wall-interference correction estimates when substantial wing stalling is encountered.