A practical method to determine true pitching moment for internal balance wind tunnel testing with longitudinal variation in flow angularity
Kevin W. Kelly. A Practical Method to Determine True Pitching Moment for Internal Balance Wind Tunnel Testing with Longitudinal Variation in Flow Angularity. AIAA Guidance, Navigation, and Control Conference, 13-17 of January 2014, National Harbor, Maryland, http://dx.doi.org/10.2514/6.2014-0614.
Data reduction and correction checks for Walter H. Beech Wind Tunnel internal balance tests demonstrate an offset in observed pitching moment for model upright and inverted test runs. Root-cause analysis determines longitudinal variation in flow angularity is the primary cause, which is quantified via direct probe measurements. A horizontal tail effectiveness correction is developed to apply the flow angularity variation to a model's longitudinal lifting surfaces, with good resulting upright-to-inverted pitching moment correlation.
Paper submitted to the AIAA Guidance, Navigation, and Control Conference held at Gaylord National Resort & Convention Center, National Harbor (Maryland), 13-17 of January 2014.