Simple method for particle tracing in 2-D unsteady flows

A particle tracing method integrated into an unsteady Navier-Stokes solver with structured 2-D grids is presented. Particles may be released anywhere in the flowfield and are traced in time by convecting them with the local flow velocity. The localization of the particles is based on a sequential and directional search algorithm. The search algorithm provides interpolation weights at the localization point, which is needed to evaluate the local flow velocity. The method is applied to unsteady flow-fields over an impulsively started airfoil at an incidence, a single flapping airfoil, and a stationary airfoil/oscillating flap combination in tandem. It is shown that the method is accurate, efficient and robust, and remarkably captures the unsteady nature of the flowfields.


Intelligent analysis of chaos roughness in regularity of walk for a two legged robot
Kaygisiz, BH; Erkmen, İsmet; Erkmen, Aydan Müşerref (Elsevier BV, 2006-07-01)
We describe in this paper a new approach to the identification of the chaotic boundaries of regular (periodic and quasiperiodic) regions in nonlinear systems, using cell mapping equipped with measures of fractal dimension and rough sets. The proposed fractal-rough set approach considers a state space divided into cells where cell trajectories are determined using cell to cell mapping technique. All image cells in the state space, equipped with their individual fractal dimension are then classified as being ...
Optimum design of unbraced steel frames to LRFD-AISC using particle swarm optimization
Dogan, E.; Saka, M. P. (2012-04-01)
Particle Swarm method based optimum design algorithm for unbraced steel frames is presented. The Particle Swarm method is a numerical optimization technique that simulates the social behavior of birds, fishes and bugs. In nature fish school, birds flock and bugs swarm not only for reproduction but for other reasons such as finding food and escaping predators. Similar to birds seek to find food, the optimum design process seeks to find the optimum solution. In the particle swarm optimization each particle in...
A 2-D unsteady Navier-Stokes solution method with overlapping/overset moving grids
Tuncer, İsmail Hakkı (1996-01-01)
A simple, robust numerical algorithm to localize intergrid boundary points and to interpolate unsteady solution variables across 2-D, overset/overlapping, structured computational grids is presented. Overset/ overlapping grids are allowed to move in time relative to each other. The intergrid boundary points are localized in terms of three grid points on the donor grid by a directional search algorithm. The final parameters of the search algorithm give the interpolation weights at the interpolation point. Th...
Efficient hybrid discrete Fourier transform-moment method for fast analysis of large rectangular arrays
Chou, HT; Ho, HK; Pathak, PH; Nepa, P; Aydın Çivi, Hatice Özlem (Institution of Engineering and Technology (IET), 2002-02-01)
A novel approach combining the moment method (MoM) and the discrete Fourier transform (DFT) is developed for the fast analysis of electromagnetic (EM) radiation/scattering from electrically large, finite, planar rectangular arrays. In particular, the unknown array distribution to be solved is represented in terms of the DFT within the MoM for a given array excitation. The proposed DFT-MoM approach for large arrays has the advantage that it can overcome the inefficiency of the conventional MoM approach by dr...
Extraction of 3D transform and scale invariant patches from range scans
Akagunduz, Erdern; Ulusoy, İlkay (2007-06-22)
An algorithm is proposed to extract transformation and scale invariant 3D fundamental elements from the surface structure of 3D range scan data. The surface is described by mean and Gaussian curvature values at every data point at various scales and a scale-space search is performed in order to extract the fundamental structures and to estimate the location and the scale of each fundamental structure. The extracted fundamental structures can later be used as nodes in a topological graph where the links betw...
Citation Formats
İ. H. Tuncer, “Simple method for particle tracing in 2-D unsteady flows,” 1997, vol. 13, Accessed: 00, 2021. [Online]. Available: