The influence that the kinematics of pitching and heaving 2D airfoils has on aerodynamic forces is investigated using direct numerical simulations a force decomposition algorithm. Large-amplitude motions are considered (of order one chord), with moderate Reynolds numbers reduced frequencies $O(1)$ , varying mean pitch angle phase shift between motions. Our results show surface vorticity contribution (viscous effect) to negligible compared contributions from body motion (fluid inertia) within...

We have performed particle-resolved direct numerical simulations of many heavy non-spherical particles settling under gravity in the dilute regime. The are oblate spheroids aspect ratio 1.5 and density 1.5. Two Galileo numbers considered, namely 111 152, for which a single spheroid follows steady vertical oblique path, respectively. In both cases, strongly inhomogeneous spatial distribution disperse phase form columnar clusters is observed, with significantly enhanced average velocity as...

Numerical simulations of the auto-rotation a model winged seed are presented.The calculations performed by solving simultaneously Navier-Stokes equations for flow surrounding and rigid-body motion seed.The Reynolds number based on descent speed characteristic chord length is varied in range 80 -240.Within this range, attains an asymptotic state with finite amplitude auto-rotation, while smaller values no observed.The characterized coning pitch angles, angular velocity horizontal translation...

Abstract Direct numerical simulations of the settling a spherical particle under action gravity in slightly perturbed ambient fluid have been performed. The perturbations are generated using synthetic turbulence inflow generator method, and their length scale intensity varied to study influence on motion. Galileo number is 151 solid-to-fluid density ratio 1.5, so that absence perturbations, settles following steady vertical trajectory. It has found trigger formation double-threaded vortical...

We present experiments and simulations of plunging maneuvers large amplitude, for velocity ratios 2, defined as the ratio between peak plunge freestream velocity. explore effect airfoil shape by considering a NACA 0012 wing flat plate. The are performed with wings aspect 4 4.86, whereas using model an infinite-aspect-ratio wing. report time evolution force coefficients flow visualizations. A good qualitative agreement is found simulations, small discrepancies in maximum minimum lift observed...

We present fully resolved Direct Numerical Simulations of 2D flow over a moving airfoil, using an in-house code that solves the Navier-Stokes equations incompressible with Immersed Boundary Method. A combination sinusoidal plunging and pitching motions is imposed to airfoil. Starting from thrust producing case (Reynolds number, Re = 1000, reduced frequency, k 1.41, amplitude h0/c 1, θ0 30°, phase shift ϕ 90°), we increase mean angle (in order produce lift) vary between (to optimize direction...

We present two-dimensional and three-dimensional (3-D) direct numerical simulations of large-amplitude plunging maneuvers at Reynolds numbers 5000, with velocity ratios , 1, 2. For all cases, the evolution force coefficients is qualitatively similar. The lift coefficient presents a pronounced peak toward end acceleration phase maneuver, local minimum in deceleration phase, second maneuver. amplitude main increases linearly limited effect number negligible three-dimensionality flow. On other...

This study presents a computational tool to accurately simulate the flow around flapping-wing micro air vehicle in free flight. The is obtained by solving Navier–Stokes equations of incompressible using an immersed boundary method. motion subject aerodynamic and gravity forces rigid body quaternion formulation for vehicle’s orientation. Both sets are solved coupled way. methodology illustrated simulating model uncontrolled, symmetric, forward flight at low Reynolds number, where wing...

This paper reports a combined experimental and numerical study of the flow over rigid airfoil in flapping motion. The setup consists heaving pitching at moderate Reynolds number ([Formula: see text]), Strouhal St = 0.1. aim is to assess accuracy two-dimensional direct simulations predicting aerodynamic forces configuration, which nominally but verge three-dimensionality. assessment carried out with experiments, including field force measurements particle image velocimetry load cell....

We present a simple modification of the direct-forcing immersed boundary method (IBM) proposed by Uhlmann [J. Comput. Phys, 2005] in order to enable it be applied particulate flows with solid-to-fluid density ratios around unity. The main difference respect original formulation lies particle velocity update which is performed directly after preliminary field has been computed absence any IBM volume forcing term. In addition, we apply term entire space occupied solid object (instead vicinity...

We present an efficient implementation for running three-dimensional numerical simulations of fluid-structure interaction problems on single GPUs, based Nvidia CUDA through Numba and Python. The incompressible flow around moving bodies is solved in this framework the Immersed Boundary Method tailored GPU, where different GPU grid architectures are exploited to optimize overall performance. By targeting a single-GPU, we avoid GPU-CPU GPU-GPU communication bottlenecks, since all simulation...

We present an efficient implementation for running three-dimensional numerical simulations of fluid-structure interaction problems on single GPUs, based Nvidia CUDA through Numba and Python.The incompressible flow around moving bodies is solved in this framework the Immersed Boundary Method tailored GPU, where different GPU grid architectures are exploited to optimize overall performance.By targeting a single-GPU, we avoid GPU-CPU GPU-GPU communication bottlenecks, since all simulation data...

We present experiments and simulations of plunging maneuvers large amplitude, for velocity ratios G=1 2. explore the effect airfoil shape by considering a NACA0012 wing flat plate. The are performed with wings aspect ratio 4 4.86, while using model an infinite aspect-ratio wing. A good qualitative agreement is found between simulations, small discrepancies in maximum minimum lift coefficients observed during somewhat larger post-maneuver phase. It that seems to have on coefficient but drag...

Background Acute bacterial conjunctivitis (ABC) is a relatively common medical condition caused by different pathogens. Although it rarely threatens vision, one of the most conditions that cause red eyes and may be accompanied discomfort discharge. The study aimed to identify characterize inpatients with ABC treated topical antibiotics. Methods EHRead® technology, based on natural language processing (NLP) machine learning, was used extract analyze clinical information in electronic health...

We have performed particle-resolved direct numerical simulations of many heavy non-spherical particles settling under gravity in the dilute regime. The are oblate spheroids aspect ratio 1.5 and density 1.5. Two Galileo numbers considered, namely 111 152, for which a single spheroid follows steady vertical oblique path, respectively. In both cases, strongly inhomogeneous spatial distribution disperse phase form columnar clusters is observed, with significantly enhanced average velocity as...