Searched for: subject%3A%22skin%255C-friction%22
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İlter, Yasin Kaan (author), Ünal, Uğur Oral (author), Shi, Weichao (author), Tokgoz, S. (author), Atlar, Mehmet (author)
Dimpled surfaces have gained increasing attention in recent years for their potential to reduce turbulent skin friction, a capability previously acknowledged for its beneficial implications on heat transfer. As a passive drag reduction method, dimpled surfaces offer significant advantages for marine applications due to their effectiveness and...
journal article 2024
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Ujjaini Kempaiah, K. (author)
A flying aircraft consumes fuel to overcome air resistance during its motion. A significant part of this consumption (55%) is due to turbulent skin friction arising at the interface of the aircraft surface and the air. The current work aims to develop and investigate relevant turbulent skin-friction reduction techniques and assist in advancing...
doctoral thesis 2023
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Jacobs, Dianne (author)
This research looked into the influence of negative skin friction on timber piles in Amsterdam. Tensile load tests were performed on new, instrumented timber piles at Overamstel in Amsterdam. The negative skin friction calculated from the test data was compared to the negative skin friction from NEN 9997-1 for a single pile. The test results...
master thesis 2021
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Sem, Jacopo (author)
The reduction of turbulent skin-friction drag has the potential to generate numerous societal benefits. In large-scale industrial applications, the largest share of energy consumption goes into overcoming the friction drag produced by turbulent boundary layers formed on the outside wall. Estimates assess that over 50% of the total fuel burn is...
master thesis 2021
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Levoni, Andrea (author)
In the aviation, maritime and oil&gas sector, the potential benefit in yearly savings deriving from the reduction of turbulent skin-friction drag through active flow control are estimated in the millions of U.S. Dollars and million tonnes of CO2 emissions. Research in this topic has brought forward numerous techniques, offering enticing drag...
master thesis 2021
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Ujjaini Kempaiah, Kushal (author)
Reduction of skin-friction drag over a fully developed canonical zero-pressure gradient turbulent boundary layer (ZPGTBL) subjected to spanwise oscillation is measured using planar particle image velocimetry (PIV). The experiments are conducted at Re<sub>θ</sub> of 1000 and 1800, the chosen range of spanwise oscillations amplitude and frequency...
master thesis 2019
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Zhang, S. (author), Zeng, X. (author), Igartua, A. (author), Rodriguez-Vidal, E. (author), van der Heide, E. (author)
Surface texture is important for contact mechanical and tribological phenomena such as the contact area and friction. In this research, three different types of geometrical microstructures were designed and fabricated by pulsed laser surface texturing as semi-symmetric (grooved channel), asymmetric fractal (Hilbert curve), and symmetric...
journal article 2017
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de Wolf, J.S. (author)
This thesis aims to analyse the conservatism in the current Dutch recommendations on the external friction angle 𝛿 of diaphragm walls: 𝛿 = 𝑚𝑖𝑛[𝜙, 20°] (for curved slip surfaces) (CUR/COB, 2010), by means of an experimental investigation. Based on literature, two sources of conservatism are identified: 1) filter cake contamination by excavated...
master thesis 2016
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Boersma, J.Y. (author)
For conceptual aircraft design to include accurate laminar flow prediction, a link between modern computational tools to determine laminar-to-turbulent boundary layer transition and fast sizing methods is required. For swept wings, it is crucial to include the highly unstable three-dimensional crossflow component of the boundary layer. These...
master thesis 2016
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Nedumaran, A.K. (author)
Vortex Generators (VGs) are flow control devices commonly applied in wind turbine blades, among other applications. A significant advance in the design of wind turbine blades would be the integration of vortex generators in the aerofoil optimisation process. Currently, aerofoil optimisation relies on either computational fluid dynamics or...
master thesis 2016
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Bal, S.R. (author)
The main driver of developments in the wind energy sector is not the absolute maximization of energy capture, but the reduction of the Cost of Energy (CoE). More and more research is carried out to investigate control of the air flow to reduce fatigue loads, structural requirements, and apply novel control strategies to ultimately reduce this...
master thesis 2015
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Haryono, I.S. (author)
Construction of deep excavation in densely populated area is not a trivial thing. The execution could induce disturbance to the soil and adjacent buildings. Many researches have analysed building responses to deep excavation or tunnelling projects. But the studies were mostly limited to buildings with shallow foundations. The importance of...
master thesis 2013
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Spruit, P.J. (author)
Singapore is an island city-state in the South-East region of Asia. With an area of approximately 700 km2 and about 5.0 million inhabitants, Singapore is relatively small and densely populated. To be able to expand economic activities, Singapore has on-going land reclamation projects. The reclaimed land is used for the construction of new...
master thesis 2011
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Grosse, S. (author), Schröder, W. (author)
Wall-shear stress results from the relative motion of a fluid over a body surface as a consequence of the no-slip condition of the fluid in the vicinity of the wall. To determine the two-dimensional wall-shear stress distribution is of utter importance in theoretical and applied turbulence research. In this article, characteristics of the Micro...
journal article 2009
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Abbas, A. (author), Dias, J. (author)
With the increase in fuel prices, flow control technologies are becoming of greater interest as being the means of achieving a technology quantum leap in the next generation of aircrafts, providing the means to achieve significant reduction in drag (fuel burn) and improvements in aircraft performance, shortening thus the path to accomplish the...
conference paper 2006
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Hoffman, J. (author)
In this paper we use a General Galerkin (G2) method to simulate drag crisis for a sphere, where the unresolved turbulent boundary layer is modeled as a decreasing skin friction.
conference paper 2006
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Motallebi, F. (author)
report 1995
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Khalid, M. (author)
A new method, to obtain skin friction reduction by installing airbearing channels on a smooth surface in uniform flow was investigated. The measurements were made by a servo-controlled skin friction balance. The parametric studies of the channel having step dimensions less than the laminar sublayer thicknesses and placed in flows of free stream...
report 1986
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Kooi, J.W. (author)
An experiment is described in which a nominal normal shock impinges on a turbulent flat plate boundary layer. The wall pressure distribution in the interaction region was measured for Mach numbers in front of the shock of 1.40, 1.44 and 1.46. The Reynolds number based on shock position was 18 X 10(6) and based on momentum thickness at the start...
report 1978
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Lindhout, J.P.F. (author)
A computer program has been prepared for the calculation of turbulent boundary layer development, based on a 3-D version of the turbulent energy method. The method is briefly discussed. The computer program is described in detail. The present program is restricted to developable surfaces.
report 1975
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