Optical System for High-Speed 3D Velocimetry

Unsteady processes, such as vortex shedding and local extinction, play a key role in augmentor stability.These processes occur on fast timescales, and can involve complex, three-dimensional (3D) structures.To fully elucidate unsteady processes, such as flame ignition and blowout, fast diagnostics that can provide information over a 3D volume are needed.In this research program, we are developing a flexible imaging system for applying fast, 3D diagnostics to gas turbine combustors.The system will serve as a platform technology that can be applied to a range of combustion diagnostics, including velocimetry, emissions imaging, and laser-induced fluorescence.The Phase I project was focused on application to high-speed three-dimensional, three-component (3D3C) particle image velocimetry (PIV).We developed a system for time-resolved 3D3C PIV and demonstrated it on laboratory flows against stereo PIV.In Phase II, we will optimize and fully characterize the technique for velocimetry, apply the technique to other combustion parameters, and demonstrate the technology in a gas turbine combustor rig.