Prof. Dr. Nikolay Vinnichenko
Faculty of Physics of Lomonosov Moscow State University

Dr. Nikolay Vinnichenko is now associate professor at the Faculty of Physics of Lomonosov Moscow State University, where he works since 2009. He graduated from Lomonosov Moscow State University (Faculty of Physics) in 2006 and obtained PhD in Physics (Chemical physics, physics of combustion and explosion, physics of extreme matter states) in 2009. Although he began his career in numerical simulations of fluid flows, his current research interests include also quantitative visualization techniques, such as Background Oriented Schlieren, Particle Image Velocimetry and Infrared Thermography. He is the author of 1 monograph, 25 papers in peer-reviewed journals and about 80 conference proceedings. 

Background Oriented Schlieren and other techniques based on pattern matching

The course will be held from September 22 to 28 and will be structured as follows:

Day 1 – Sept, 22 From 11:00 to 13:00 (Spanish Time) in classroom 7.1.J07 EPS UC3M Leganés

Conventional refractometry: shadowgraphy, schlieren, rainbow schlieren, lens-and-grid schlieren. BOS optical setup and measurement procedure. BOS data assimilation for seedless velocimetry. Qualitative BOS and BOS with natural background. BOS optics: conventional and telecentric BOS. Reconstruction of refractive index from its first spatial derivatives. BOS in gases and liquids. BOS and PIV.

Day 2 – Sept, 23 From 11:00 to 13:00 (Spanish Time) in classroom 7.2.J05 EPS UC3M Leganés

Other techniques based on displacement estimation from pattern matching: stereo vision, aerial photography, digital gradient sensing, measurements of liquid surface relief, structured light profilometry of opaque and specular objects. Experimental difficulties, employed patterns and displacement determination techniques.

Day 3 – Sept, 26 From 09:00 to 11:00 (Spanish Time) in classroom 7.2.J05 EPS UC3M Leganés

Displacement determination techniques, taken from PIV: direct and Fourier-based cross-correlation, PTV (dot tracking), Horn-Schunck and Lucas-Kanade optical flow algorithms. BOS image processing performance assessment using synthetic images. Displacement determination techniques, taken from profilometry and interferometry: Fourier Transform Profilometry, Phase Shifting Profilometry.

Day 4 – Sept, 27 From 09:00 to 11:00 (Spanish Time) in classroom 7.2.J05 EPS UC3M Leganés

Color and multi-frame techniques for BOS: color cross-correlation, colored grid, monochrome and color Phase Shifting Profilometry, M-arrays. Influence of color cross-talk and gamma nonlinearity. BOS for axisymmetric flows. Tomographic BOS for 3D flows.

Day 5- Sept, 28 From 09:00 to 11:00 (Spanish Time) in classroom 7.2.J05 EPS UC3M Leganés

Live demonstrations of BOS measurements in class.

Temperature (̊C) fields for convective plume above a heated horizontal wire immersed in water.

Surface elevation and surface temperature fields, obtained with Moon-Glade BOS and infrared thermography for Rayleigh-Benard convection in distilled water and silicone oil.

Literature:

1. G.E.A. Meier // Exp. Fluids, Vol. 33, pp. 181–187, 2002.

2. M. Raffel // Exp. Fluids, Vol. 56, 60, 2015.

3. G.S. Settles. Schlieren and shadowgraph techniques. Springer, Berlin, Heidelberg, 2001.

4. J. Salvi et al. // Pattern Recognit., Vol. 43(8), pp. 2666-2680, 2010.

5. F. Moisy, M. Rabaud, K. Salsac // Exp. Fluids, Vol. 46(6), pp. 1021-1036, 2009.

6. N.A. Vinnichenko et al. // Exp. Therm. Fluid Sci., Vol. 114, 110051, 2020.

7. S. Wildeman // Exp. Fluids, Vol. 59(6), 97, 2018.

8. B. Atcheson, W. Heidrich, I. Ihrke // Exp. Fluids, Vol. 46(3), 467-476, 2009.

9. F. Leopold et al. // Proc. SPIE, Vol. 11160, 1116008, 2019.

10. M. Ota et al. // Meas. Sci. Technol., Vol. 22, 104011, 2011.

11. C. Periasamy, H.V. Tippur // Appl. Opt., Vol. 51(12), pp. 2088-2097, 2012.

12. F. Nicolas et al. // Exp. Fluids, Vol. 58(5), 46, 2017.