Influence of Leading Edge Oscillatory Blowing on Time-Accurate Dynamic Store Separation

摘要

The primary objective of this research is to support the static and dynamic characterization and the time-accurate dynamic load data acquisition of store separation from a cavity with leading edge oscillatory blowing. Developing an understanding of, and potentially controlling, pitch bifurcation of a store release is a motivation for this research. The apparatus and data acquisition system was used in a two-part experiment to collect both static and dynamic testing data in the AFIT low speed wind tunnel in speeds of 60, 100, and 120 mph, from Reynolds numbers varying from 5.5e4 to 4.6e5, depending on reference length and tunnel speed. An ATI Nano25 6-DOF force and moment sensor was used to produce time-accurate force and moment measurements. Common aerodynamic trends were observed in the comparison of trials with different store model sizes and angles of attack which align with established aerodynamic analysis. The 5 Hz oscillatory flow control, using multiple flow control approaches, had a direct impact on the forces experienced by the mission store and a 5 Hz pattern in the data was observed in static positions as well as before and after store release. Data collected for the normal force, pitch moment, and axial force coefficients, depict the aerodynamic loads of a store release from a cavity environment with a developed shear layer. Phase manipulation of relative linear motor positions allowed for data collection under varying store release conditions and timings. A 180 out of phase phenomena was observed in the normal force coefficient in cases where the position of the motor was also 180 out of phase.