AAE 520 Experimental Aerodynamics Optical Techniques for Flow

AAE 520 Experimental Aerodynamics Optical Techniques for Flow Visualization • Shadowgraph • Schlieren • Interferometer All depend of the fact that the speed of light and therefore the index of refraction varies with the density. The index of refraction is approximately Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Shadowgraph Shocks appear as a dark line followed by a light line Point Source of light deflection Flow Purdue University - School of Aeronautics and Astronautics Viewing Screen

AAE 520 Experimental Aerodynamics Shadowgraph Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Schlieren Optics c a b’ a’ b Light Source d Test Section Knife edge Image Mask (knife edge) Displaced Image of source d’ c’ Image of Test Section Knife edge intercepts part of source image Density gradient causes displacement of source image Color Schlieren uses a color in place of knife edge Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Z-folded Schlieren Using Mirrors Camera Knife edge Test Section Light Source Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Color Schlieren Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Schlieren for Flight Test Purdue University - School of Aeronautics and Astronautics

AAE 520 Experimental Aerodynamics Mach-Zender Interferometer Light Source Beamsplitter Mirror Beamsplitter Test Section Purdue University - School of Aeronautics and Astronautics Image

AAE 520 Experimental Aerodynamics Purdue University - School of Aeronautics and Astronautics