Potential Use of Molecular Absorption Filters in Particle Image Velocimetry of a Mach 2 Scramjet Test Section at the University of Virginia

The Aerospace Research Laboratory at the University of Virginia currently uses Particle Image Velocimetry (PIV) to measure the velocity fields of flow through a Mach 2 Scramjet Test Section. PIV is the method of tracking seed particles as they are carried through the flow, and using their velocities to create a velocity field. This method is limited by seed particles coating the windows, known as window fouling, making seed particle tracking within the flow impossible. This paper will discuss a potential improvement to the PIV system that will attempt to reduce the effect of window fouling. The potential improvement will involve the use of a molecular iodine absorption filter, as in Planar Doppler Velocimetry (PDV), to separate out the signals of moving particles from those with little to no velocity coating the window. This paper will discuss the feasibility of this potential improvement, and describe how the improvements may be implemented.