@inproceedings{HasanuzzamanMerboldEgbers, author = {Hasanuzzaman, Gazi and Merbold, Sebastian and Egbers, Christoph}, title = {Experimentelle Untersuchung von Geb{\"a}ude-integrierten Windf{\"u}hrungen mit Laser-Doppler- Anemometrie}, series = {Lasermethoden in der Str{\"o}mungsmesstechnik, 23. Fachtagung, 8. - 10. September 2015, Dresden}, booktitle = {Lasermethoden in der Str{\"o}mungsmesstechnik, 23. Fachtagung, 8. - 10. September 2015, Dresden}, editor = {Czarske, J{\"u}rgen}, publisher = {GALA}, address = {Karlsruhe}, isbn = {978-3-9816764-1-9}, pages = {S. 64}, language = {de} } @inproceedings{HasanuzzamanMerboldMotuzetal., author = {Hasanuzzaman, Gazi and Merbold, Sebastian and Motuz, Vasyl and Egbers, Christoph}, title = {Experimental Investigation of Turbulent Structures and their Control in Boundary Layer Flow}, series = {Experimentelle Str{\"o}mungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus}, booktitle = {Experimentelle Str{\"o}mungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus}, editor = {Egbers, Christoph}, publisher = {German Association for Laser Anemometry GALA e.V.}, address = {Karlsruhe}, isbn = {978-3-9816764-2-6}, pages = {S. 27}, language = {en} } @inproceedings{HasanuzzamanMerboldMotuzetal., author = {Hasanuzzaman, Gazi and Merbold, Sebastian and Motuz, Vasyl and Egbers, Christoph}, title = {Influence of micro-blowing technique on skin friction of boundary layer flows}, series = {11th European Fluid Mechanics Conference, Sept. 12-16, 2016, Sevilla, Spain}, booktitle = {11th European Fluid Mechanics Conference, Sept. 12-16, 2016, Sevilla, Spain}, pages = {1}, language = {en} } @inproceedings{HasanuzzamanMotuzMerboldetal., author = {Hasanuzzaman, Gazi and Motuz, Vasyl and Merbold, Sebastian and Egbers, Christoph and Cuvier, Christophe and Foucaut, Jean-Marc}, title = {Turbulent boundary layer statistics under the influence of uniform micro-blowing}, series = {16th European Turbulence Conference, 21-24 August, 2017, Stockholm, Sweden}, booktitle = {16th European Turbulence Conference, 21-24 August, 2017, Stockholm, Sweden}, pages = {1}, language = {en} } @inproceedings{HasanuzzamanMerboldMotuzetal., author = {Hasanuzzaman, Gazi and Merbold, Sebastian and Motuz, Vasyl and Egbers, Christoph and Cuvier, Christophe and Foucaut, Jean-Marc}, title = {Experimental investigation of active control in turbulent boundary layer using uniform blowing}, series = {Proceedings of the 5th International Conference on Experimental Fluid Mechanics, Munich 2018}, booktitle = {Proceedings of the 5th International Conference on Experimental Fluid Mechanics, Munich 2018}, editor = {K{\"a}hler, Christian J. and Hain, Rainer and Scharnowski, Sven and Fuchs, Thomas}, publisher = {Institute of Fluid Mechanics and Aerodynamics, Universit{\"a}t der Bundeswehr}, address = {Neubiberg}, isbn = {978-3-943207-32-3}, pages = {180 -- 185}, language = {en} } @misc{HasanuzzamanMerboldCuvieretal., author = {Hasanuzzaman, Gazi and Merbold, Sebastian and Cuvier, Christophe and Motuz, Vasyl and Foucaut, Jean-Marc and Egbers, Christoph}, title = {Experimental investigation of turbulent boundary layers at high Reynolds number with uniform blowing, part I: statistics}, series = {Journal of Turbulence}, journal = {Journal of Turbulence}, number = {3}, issn = {1468-5248}, doi = {10.1080/14685248.2020.1740239}, pages = {129 -- 165}, abstract = {Uniform blowing in wall bounded shear flows is well known for its drag reducing effects and has long been investigated ever since. However, many contemporary and former research on this topic has confirmed the drag reducing effect but very less is known regarding how blowing is effecting the Reynolds stresses at high Reynolds number. Therefore, effect of uniform blowing has been experimentally investigated using Stereo Particle Image Velocimetry (SPIV) measurements in a zero pressure gradient turbulent boundary layer (TBL). The data presented in this literature covers a large range of high Reynolds number flow e.g. Reθ = 7500∼19763 where Reynolds number is based on the momentum thickness. Upstream blowing was varied from 1\%∼6\% of free stream velocity and measurements were taken downstream after a short interval. Logarithmic and outer region of the TBL was given special attention in terms of investigating statistics and turbulence properties.}, language = {en} } @phdthesis{Hasanuzzaman, author = {Hasanuzzaman, Gazi}, title = {Experimental investigation of turbulent boundary layer with uniform blowing at moderate and high Reynolds numbers}, publisher = {BTU}, address = {Cottbus-Senftenberg}, doi = {10.26127/BTUOpen-5566}, pages = {XXIII, 152}, abstract = {Experimental investigation in turbulent boundary layer flows represents one of the canonical geometries of wall bounded shear flows. Utmost relevance of such experiments, however, is applied in the engineering applications in aerospace and marine industries. In particular, continuous effort is being imparted to explore the underlying physics of the flow in order to develop models for numerical tools and to achieve flow control. Within the scope of this Ph. D. topic, application of active control method such as micro-blowing effect in the incompressible, zero pressure gradient turbulent boundary layer was investigated. Turbulent boundary layer flow is particularly interesting as well as challenging due to the presence of different interacting scales which are increasingly becoming significant as the flow inertial conditions keeps growing. Therefore, energy content of the coherent structures in outer layer becomes stronger and necessitates measurements in relatively large Reynolds number. Present control experiments in turbulent boundary layer can be split into two different work segments, where one is objected towards the data measurements in turbulent boundary layer over smooth surface with and without any external perturbation. Here, perturbation is applied in the form of wall normal blowing while keeping the magnitude of blowing very low compared to the free stream velocity. For the subsequent results reported here, magnitude of blowing ratio was varied between 0\%~6\%. In the first part of the present thesis e.g. 0.415×10e+3≤Reτ≤1.160×10e+3, measurements were performed at the Brandenburg University of Technology wind tunnel. Non-intrusive Laser Doppler Anemometry was applied to carry out a series of measurements on a zero pressure gradient flat plate turbulent boundary layer. Blowing ratio through the perforated surface was varied between 0.17\%~1.52\% of the free stream velocity. To a maximum of 50\% reduction in friction drag was achieved. For the measurements on the upper range of the stated Reynolds number, were conducted at the boundary layer wind tunnel. This boundary layer wind tunnel offers a spatially developed turbulent boundary layer over a flat plate within 2.2×10e+3≤Reτ≤5.5×10e+3 with an excellent spatial resolution. With the help of Stereo Particle Image Velocimetry technique, measurement of the velocity components were obtained covering entire boundary layer in streamwise wall normal plane. In addition, time resolved measurements were also obtained in spanwise and wall-normal plane in order to look into the morphology of turbulent structures immediately above the blowing area.}, language = {en} } @misc{HasanuzzamanMerboldMotuzetal., author = {Hasanuzzaman, Gazi and Merbold, Sebastian and Motuz, Vasyl and Egbers, Christoph}, title = {Enhanced outer peaks in turbulent boundary layer using uniform blowing at moderate Reynolds number}, series = {Journal of Turbulence}, volume = {23}, journal = {Journal of Turbulence}, number = {1-2}, issn = {1468-5248}, doi = {10.1080/14685248.2021.2014058}, pages = {68 -- 95}, language = {en} } @misc{HasanuzzamanEivaziMerboldetal., author = {Hasanuzzaman, Gazi and Eivazi, Hamidreza and Merbold, Sebastian and Egbers, Christoph and Vinuesa, Ricardo}, title = {Enhancement of PIV measurements via physics-informed neural networks}, series = {Measurement Science and Technology}, journal = {Measurement Science and Technology}, issn = {1361-6501}, doi = {10.1088/1361-6501/aca9eb}, language = {en} } @misc{HasanuzzamanEgbers, author = {Hasanuzzaman, Gazi and Egbers, Christoph}, title = {Flow control of a turbulent boundary layer using uniform blowing}, series = {Progress in Turbulence X : Proceedings of the iTi Conference on Turbulence 2023}, journal = {Progress in Turbulence X : Proceedings of the iTi Conference on Turbulence 2023}, isbn = {978-3-031-55924-2}, doi = {10.1007/978-3-031-55924-2_36}, language = {en} }