Active "Fail Safe" Micro-Array Flow Control for Advanced Embedded Propulsion Systems

The primary objective of this research effort was to develop and analytically demonstrate enhanced first generation active “fail-safe” hybrid flow-control techniques to simultaneously manage the boundary layer on the vehicle fore-body and to control the secondary flow generated within modern serpentine or embedded inlet S-duct configurations. The enhanced first-generation technique focused on both micro-vanes and micro-ramps highly-integrated with micro-jets to provide non-linear augmentation for the “strength” or effectiveness of highly-integrated flow control systems. The study focused on the micro-jet mass flow ratio (Wjet/Waip) range from 0.10% to 0.30% and jet total pressure ratios (Pjet/Po) from 1.0 to 3.0. The engine bleed airflow range under study represents about a 10 fold decrease in micro-jet airflow than previously required. Therefore, by preconditioning, or injecting a very small amount of high-pressure jet flow into the vortex generated by the micro-vane and/or micro-ramp, active flow control is achieved and substantial augmentation of the controlling flow is realized. NOMENCLATURE