Holographic Investigation Of Shock Wave Diffraction

Holographic investigation of shock wave diffraction Romuald Pawluczyk and Zbigniew KraskaDepartament of Physical Optics, Central Laboratory of OpticsKamionkowska 18, 03-805 Warsaw, PolandGrzegorz KowalewskiInstitute of Fluid - Plow Machinery, Technical University of Lodz Gdanska 155, 90-924 Lodz, PolandAbstractPressure shock wave is created in a shock tube which ends with visualization chamber with two transparent glass windows. Different kinds of obstacles to the shock wave are placed in the chamber. Double-exsposure holographic interferometry realized by a Q-swit- ched ruby laser is applied to investigate the events happening in the chamber. Some preli­ minary results of experiments are presented in the report.The interaction of shock wave with different kinds of obstacles is still an important problem. As many other aerodynamical problems it can be investigated by different optical methods, but holographic interferoraetry promises the greatest advantages. So, in our ex­ periments a well known [1-3] double-exposure holographic interferometry technique has been used as investigation tool of transparent objects.The object of our investigations - a pressure shock wave, is created in a high pressu­ re shock tube. This tube consists of three main parts: a store chamber, a cylindrical tu­ be where the shock wave is guided and formed, and visualization chamber in the end. The first part is a high pressure cylindrical chamber which is filled in with air at preselec­ ted nressure controlled by means of pressure gauge. One end of this chamber is connected