Flow over macroscopic hexagonal structured surfaces. Experimental Investigation

Doctoral Thesis / Dissertation from the year 2014 in the subject Engineering - Mechanical Engineering, grade: 1,3, Brandenburg Technical University Cottbus, language: English, abstract: The flow over macroscopic patterned/structured surfaces was investigated in a subsonic wind tunnel over Reynolds numbers ranging from 3.14 x 104 to 2.77 x 105 for cylinders and from 5.34 x 105 to 11.27 x 106 for plates. The investigations were accomplished by measuring local and global drag, velocity profiles and by visualization of the flow above the surface. Flow visualization was carried out by using oil-film technique and velocity profile measurements to elucidate the observed effect, and hence present the mechanism responsible for theobserved drag reduction. Investigations on structured plates were performed with the help of hot wire anemometry and oil film interferometry. The main concern of the experiments on structured plates was to examine the effect of hexagonal structures on local and global drag of a structured plate. It was accomplished by determining and analyzing the boundary layer quantities like shear stress velocities, shear stress coefficients and momentum thicknesses over a selected Reynolds number range and various locations in streamwise direction. Finally, a number of configurations of a wind turbine made of smooth and structured blades were investigated to compare their efficiencies at various flow velocities.

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An expert in Experimental Fluid dynamics, I did my Bachelors and Masters in Mechanical Engineering from Universities of Mannheim and Germany. During my studies i got the opportunity to gain initial industrial experience at EADS (European Air Defence and Space) and ELOPAK. I completed my PhD from the Technical University of Cottbus, Germany. My doctoral work focused on investigating drag reduction using structured surfaces in a wind tunnel. After submitting the Dissertation i worked for Siemens in Berlin as Test Engineer. Recieved research Grant of 0.1 million Euros from DAAD. Currently developing micro gas turbines at institute of Aeroengines in BTU Cottbus. Employment history Scientist - BTU Cottbus 2020 - Present Visiting Scientist - University of Rostock, Germany, 2019 - 2020 Assistant Professor - University of Lahore, Pakistan, 2015 - 2020 Research Engineer - Siemens Power, Germany, 2014 Research Associate - Technical University of Cottbus, 2011-2013 Design engineer - AEDesign, Lahore, Pakistan, 2009-2011