Drag Reduction via Phase Randomization in Turbulent Pipe Flow

Tugluk, Ozan
Tarman, Hakan I.
In this study, possibility of reducing drag in turbulent pipe flow via phase randomization is investigated. Phase randomization is a passive drag reduction mechanism, the main idea behind which is, reduction in drag can be obtained via distrupting the wave-like structures present in the flow. To facilitate the investigation flow in a circular cylindrical pipe is simulated numerically. DNS (direct numerical simulation) approach is used with a solenoidal spectral formulation, hence the continuity equation is automatically satisfied (Tugluk and Tarman, Acta Mech 223(5): 921-935, 2012). Simulations are performed for flow driven by a constant mass flux, at a bulk Reynolds number (Re) of 4900. Legendre polynomials are used in constructing the solenoidal basis functions employed in the numerical method.


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In this study, it is aimed the numerically investigation of the flow of liner PTT (Phan-Thien-Tanner) fluid, which is a viscoelastic fluid model over limited square obstacle by finite volume method. The finite volume method has been used for simultaneous solution of continuity, momentum and fluid model equations with appropriate boundary conditions. The effects of the inertia in terms of Reynolds number, Re, (0 < Re < 20) and the of elasticity in terms of Weissenberg number, We, (1 < We < 15) of PTT flow ...
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Flow Characterization of Viscoelastic Fluids around Square Obstacle
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This study focuses on the computational implementation of structured non-uniform finite volume method for the 2-D laminar flow of viscoelastic fluid past a square section of cylinder in a confined channel with a blockage ratio 1/4 for Re = 10(-)(4), 5, 10 and 20. Oldroyd-B model (constant viscosity with elasticity) and the PTT model (shear-thinning with elasticity) are the constitutive models considered. In this study effects of the elasticity and inertia on the drag coefficients and stress fields around th...
Effect of illumination on commensurate-incommensurate phase transition temperature in layered semiconductor TlInS2
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The shift in the commensurate to incommensurate phase transition point as a result of thermocycling between the commensurate and incommensurate phases in the layered ferroelectric semiconductor TlInS2 is investigated, It is shown that the shifting of the phase transition point is strongly dependent on the intensity of the incident light of illumination. The observed effect is explained by the pinning process which is mole effective under illumination. Copyright (C) 1996 Elsevier Science Ltd
Direct numerical simulation of pipe flow using a solenoidal spectral method
Tugluk, Ozan; Tarman, Işık Hakan (2012-05-01)
In this study, a numerical method based on solenoidal basis functions, for the simulation of incompressible flow through a circular-cylindrical pipe, is presented. The solenoidal bases utilized in the study are formulated using the Legendre polynomials. Legendre polynomials are favorable, both for the form of the basis functions and for the inner product integrals arising from the Galerkin-type projection used. The projection is performed onto the dual solenoidal bases, eliminating the pressure variable, si...
Citation Formats
O. Tugluk and H. I. Tarman, “Drag Reduction via Phase Randomization in Turbulent Pipe Flow,” METU, Ankara Turkey, 2015, vol. 112, p. 463, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/65161.