Browsing by Subject "Turbulence"
Now showing items 1-20 of 27
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Conference Object
CFD modeling of turbulent flow and particle deposition in human lungs
(Affiliation: UCY-CompSci Computational Sciences Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, CyprusCorrespondence Address: Radhakrishnan, H.UCY-CompSci Computational Sciences Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprusemail: hariradh@ucy.ac.cy, 2009)Understanding transport and deposition of inhaled particles in the human airways plays a crucial role in the targeted therapy of pulmonary diseases, and the administration of inhaled medicines. Numerous researchers have ...
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Article
Coherent structures in oscillating turbulent boundary layers over a fixed rippled bed
(2013)Coherent structures generated by oscillating turbulent boundary layers with or without a unidirectional current over a fixed, rippled bed are presented. The effect of ripple height and current intensity on the characteristics ...
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Book
Complex effects in Large Eddy Simulations
(Springer, 2007)
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Conference Object
Computational fluid dynamics (CFD) Simulations of aerosol deposition in the lungs
(TSFP-9, 2015)In the current study, Large Eddy Simulations (LES) are used to investigate the transport and deposition of inhaled aerosol particles (dp = 0.1, 0.5, 1, 2.5, 5, 10 μm) in a realistic geometry of the human airways under ...
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Article
The contribution of active and inactive structures to the statistics of a turbulent pipe flow
(2017)The current study is a short follow-up to our most recent work (Stylianou et al., 2016), where among other things we have presented an effective criterion suitable for distinguishing large-scale coherent structures with ...
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Article
Direct numerical simulation of turbulent liquid metal flow entering a magnetic field
(2013)This paper presents direct numerical simulations (DNS) of fully developed turbulent liquid-metal flow in a circular duct entering a magnetic field. The case of a magnetohydrodynamic flow leaving a strong magnetic field has ...
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Article
Dispersed-phase structural anisotropy in homogeneous magnetohydrodynamic turbulence at low magnetic Reynolds number
(2008)A new tensor statistic, the dispersed-phase structure dimensionality Dp, is defined to describe the preferred orientation of clusters of discrete bodies. The evolution of Dp is calculated via direct numerical simulations ...
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Conference Object
The effect of flow rate, head position, and inhaler orientation on the airflow and particle deposition in an mri-based mouth-throat geometry
(International Symposium on Turbulence and Shear Flow Phenomena, TSFP10, 2017)The mouth-throat plays a key role in the administration of inhaled medicines. It is an area of intense filtration, where an unacceptably high fraction of the released drug dose is deposited and thus wasted. Due to the ...
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Doctoral Thesis Open Access
Extensions to structure-based turbulence theory and models, with applications to internal and simple biological flows
(Πανεπιστήμιο Κύπρου, Πολυτεχνική Σχολή / University of Cyprus, Faculty of Engineering, 2016-12)Η Θεωρία Δομής της Τύρβης (ΘΔΤ) αποτελεί ένα ολοκληρωμένο μαθηματικό πλαίσιο, όπου η ποσοτικοποίηση των ποικίλων πτυχών των συνεκτικών δομών της τύρβης επιτυγχάνεται μέσω των Τανυστών Δομής της Τύρβης (ΤΔΤ). Αυτή η θεωρία ...
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Conference Object
Fully turbulent flow in a physiologically realistic human airway bifurcation
(TSFP-9, 2015)Recent computational studies have shown that the airflow in the upper human airways is turbulent during much of the respiratory cycle. A feature of respiratory airflow that poses a challenge to computations based on ...
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Article
Large Eddy Simulation of near-bed pipelines in oscillatory flow
(2018)A series of unsteady, three-dimensional numerical simulations of the incompressible, oscillatory flow around a near-bed pipeline is presented. A flow at Reynolds number equal to Reαo=20,000 with respect to the oscillatory ...
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Article
Large-eddy simulation of wave turbulent boundary layer over rippled bed
(2012)Large-eddy simulation (LES) of turbulent boundary layer induced by external oscillatory flow without or with a unidirectional component over rippled bottom is presented. These flows represent prototype turbulent flows of ...
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Article
Magnetohydrodynamic turbulence at moderate magnetic Reynolds number
(2004)We consider the case of homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field at low to moderate magnetic Reynolds numbers (by moderate we mean here values as high as 20). When ...
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Conference Object
Numerical modeling of turbulent airflow and particle deposition in a bifurcating airway model
(Affiliation: UCY-CompSci Computational Sciences Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, CyprusCorrespondence Address: Radhakrishnan, H.UCY-CompSci Computational Sciences Laboratory, Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus, 2009)Understanding transport and deposition of inhaled particles in the human airways plays a crucial role in the targeted therapy of pulmonary diseases, and the administration of inhaled medicines. Numerous researchers have ...
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Conference Object
Numerical simulations of turbulent flow in an eccentric annulus of unit eccentricity
(TSFP-9, 2015)In this study, we perform Direct Numerical Simulations (DNS) of fully developed turbulent flows in eccentric annuli having different diameter ratios. Annuli of unit eccentricity, and diameter ratios of 0.2591 and 0.1395 ...
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Article
Rapid shear of initially anisotropic turbulence in a rotating frame?
(2007)In the present study, we investigate, using inviscid rapid distortion theory, the evolution of sheared turbulence in a rotating frame as a function of the rotation rate (including stable, transitional, and unstable regimes), ...
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Article
Rapidly sheared homogeneous stratified turbulence in a rotating frame
(2007)Rapid distortion theory is applied to stratified homogeneous turbulence that is sheared in a rotating frame. Insight into the stabilizing and destabilizing effects of the combined stratification and frame rotation is gained ...
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Article
Representing anisotropy of two-point second-order turbulence velocity correlations using structure tensors
(2008)A locally homogeneous representation for the two-point, second-order turbulent velocity fluctuation Rij(x,r) = 〈u′i(x)u′i(x+r)〉 is formulated in terms of three linearly independent structure tensors [Kassinos et al., J. ...
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Article
A simplified structure-based model using standard turbulence scale equations: computation of rotating wall-bounded flows
(2006)Two linear eddy-viscosity models, the v2-f and k-ω models, have been combined with an algebraic structure-based algorithm for the evaluation of the Reynolds stresses. This closure was originally designed as an integral ...
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Article
Statistical measures of structural anisotropy in MHD turbulence subjected to mean shear and frame rotation
(2006)We consider homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field while being sheared in fixed and rotating frames. We take both the frame-rotation axis and the applied magnetic ...