Evaluation of Travelling Vortex Speed by Means of Dynamic Mode Decomposition and Residual Vorticity

The article deals with the analysis of synthetic jet flow field by means of dynamic mode decomposition (DMD) method. The speed of travelling vortex ring which is connected with synthetic jet creation is evaluated using the wavelength identified from DMD modes. Vortices are identified in the DMD modes by using residual vorticity which allows to identify regions in the flow field where fluid particles perform rotational motion. The analysis is based on the data from the numerical simulation of synthetic jet into quiescent air by using ANSYS Fluent code. The regime of synthetic jet with Re = 329 and Stk = 19.7 is chosen. An increase in the vortex speed close to the orifice and then the decrease is observed with maximum reaching almost one and half of averaged blowing orifice centerline velocity

Modal Decomposition of Synthetic Jet Flow Based on CFD Computation

The article analyzes results of numerical simulation of synthetic jet flow using modal decomposition. The analyzes are based on the numerical simulation of axisymmetric unsteady laminar flow obtained using ANSYS Fluent CFD code. Three typical laminar regimes are compared from the point of view of modal decomposition. The first regime is without synthetic jet creation with Reynolds number Re = 76 and Stokes number S = 19.7. The second studied regime is defined by Re = 145 and S = 19.7. The third regime of synthetic jet work is regime with Re = 329 and S = 19.7. Modal decomposition of obtained flow fields is done using proper orthogonal decomposition (POD) where energetically most important modes are identified. The structure of POD modes is discussed together with classical approach based on phase averaged velocities

Modal Decomposition of Synthetic Jet Flow Based on CFD Computation

The article analyzes results of numerical simulation of synthetic jet flow using modal decomposition. The analyzes are based on the numerical simulation of axisymmetric unsteady laminar flow obtained using ANSYS Fluent CFD code. Three typical laminar regimes are compared from the point of view of modal decomposition. The first regime is without synthetic jet creation with Reynolds number Re = 76 and Stokes number S = 19.7. The second studied regime is defined by Re = 145 and S = 19.7. The third regime of synthetic jet work is regime with Re = 329 and S = 19.7. Modal decomposition of obtained flow fields is done using proper orthogonal decomposition (POD) where energetically most important modes are identified. The structure of POD modes is discussed together with classical approach based on phase averaged velocities

Evaluation of Travelling Vortex Speed by Means of Dynamic Mode Decomposition and Residual Vorticity

The article deals with the analysis of synthetic jet flow field by means of dynamic mode decomposition (DMD) method. The speed of travelling vortex ring which is connected with synthetic jet creation is evaluated using the wavelength identified from DMD modes. Vortices are identified in the DMD modes by using residual vorticity which allows to identify regions in the flow field where fluid particles perform rotational motion. The analysis is based on the data from the numerical simulation of synthetic jet into quiescent air by using ANSYS Fluent code. The regime of synthetic jet with Re = 329 and Stk = 19.7 is chosen. An increase in the vortex speed close to the orifice and then the decrease is observed with maximum reaching almost one and half of averaged blowing orifice centerline velocity

Analysis of turbulent synthetic jet by dynamic mode decomposition

The article deals with the analysis of CFD results of the turbulent synthetic jet. The numerical simulation of Large Eddy Simulation (LES) using commercial solver ANSYS CFX has been performed. The unsteady flow field is studied from the point of view of identification of the moving vortex ring, which has been identified both on the snapshots of flow field using swirling-strength criterion and using the Dynamic Mode Decomposition (DMD) of five periods. It is shown that travelling vortex ring vanishes due to interaction with vortex structures in the synthesised turbulent jet. DMD modes with multiple of the basic frequency of synthetic jet, which are connected with travelling vortex structure, have largest DMD amplitudes

Pulsatile flow analysis in a bend square channel by modal decomposition

The article analyzes the results of numerical simulations of pulsatile flow in a square channel with a 90° bend using Proper Orthogonal Decomposition (POD). The simulations of laminar steady and unsteady flow obtained by ANSYS Fluent commercial system were used as input for modal decomposition. Several regimes for different values of individual parameters (stationary flow component, ) were simulated. Not only energy-related modes but also modes significant from the viewpoint of energy dissipation. Other evaluated modes are the modes corresponding to the pulsatile flow frequency and the modes reflecting the flow separation at the bend