Direct numerical simulation of pipe flow using a solenoidal spectral method

Tugluk, Ozan
Tarman, Işık Hakan
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, simplifying the numerical approach to the problem. The success of the scheme in calculating turbulence statistics and its energy conserving properties is investigated. The generated numerical method is also tested by simulating the effect of drag reduction due to spanwise wall oscillations.


Direct numerical simulation of pipe flow using a solenoidal spectral method
Tuğluk, Ozan; Tarman, Işık Hakan; Department of Engineering Sciences (2012)
In this study, which is numerical in nature, direct numerical simulation (DNS) of the pipe ow is performed. For the DNS a solenoidal spectral method is employed, this involves the expansion of the velocity using divergence free functions which also satisfy the prescribed boundary conditions, and a subsequent projection of the N-S equations onto the corresponding dual space. The solenoidal functions are formulated in Legendre polynomial space, which results in more favorable forms for the inner product inte...
Experimental investigation of waveform tip injection on the characteristics of the tip vortex
Ostovan, Yashar; Uzol, Oğuz; Department of Aerospace Engineering (2011)
This study investigates the effect of chordwisely modulated tip injection on the flow and turbulence characteristics of the tip vortex through experimental measurements downstream of a rectangular half-wing that has an aspect ratio of three. This injection technique involves spanwise jets at the tip that are issued from a series of holes along the chord line normal to the freestream flow direction. The injection mass flow rate from each hole is individually controlled using computer driven solenoid valves a...
Comparison of Linear and Nonlinear Modal Reduction Approaches
Ferhatoğlu, Erhan; Dreher, Tobias; Ciğeroğlu, Ender; Krack, Malte; Özgüven, Hasan Nevzat (null; 2019-01-31)
Periodic vibration response of nonlinear mechanical systems can be efficiently computed using Harmonic Balance Method. However, computational burden may still be considerable and impede extensive parametric studies needed for, e.g., design optimization and prediction of vibration response especially when the degree of freedom is very large. In this work, the methods which had been previously developed by the authors for further model order reduction to one or a few coordinates are compared. The focus is pla...
Nonlinear modelling and control of the flow over aerofoils using CFD simulations
Karaca, H. D.; Alıcı, Gökçen Deniz; KASNAKOĞLU, Coşku (2016-09-01)
A simulation based approach for nonlinear dynamical modelling and feedback control of the drag to lift ratio for aerofoils is investigated through case studies involving NACA 23012, ag13 and b737a aerofoils. The flow around the aerofoils is studied via numerical solutions of the 2D Navier-Stokes (NS) equations. A standard computational fluid dynamics (CFD) solver is extended to be able to measure desired feedback values and to apply a control input to the flow field. The proposed modelling and control appro...
Multidimensional quantum tunneling in the Schwinger effect
Dumlu, Cesim K. (American Physical Society (APS), 2016-03-22)
We study the Schwinger effect, in which the external field having a spatiotemporal profile creates electron-positron pairs via multidimensional quantum tunneling. Our treatment is based on the trace formula for the QED effective action, whose imaginary part is represented by a sum over complex worldline solutions. The worldlines are multiperiodic, and the periods of motion collectively depend on the strength of spatial and temporal inhomogeneity. We argue that the classical action that leads to the correct ...
Citation Formats
O. Tugluk and I. H. Tarman, “Direct numerical simulation of pipe flow using a solenoidal spectral method,” ACTA MECHANICA, pp. 923–935, 2012, Accessed: 00, 2020. [Online]. Available: