Simulation of butterfly flapping with the method of dipole domains

A numerical mesh-free method of dipole domains [1,2] is used for simulation of a butterfly flapping model. This method is based on the representation of a vortex field by the set of dipole particles. The vector function D describes density of dipole moments in accordanse with Navier-Stokes or Euler equations [3]. The butterfly model consists of two flat plates with a common edge performing harmonic oscillations in two planes. New mechanism of the thrust performing is proposed

Using the dipole particles for simulation of 3d vortex flow of a viscous incompressible fluid

A fully lagrangian numerical method for simulation of 3D nonstationary flow of viscous and ideal incompressible fluid is developed in this work. This method is based on the representation of a vortex field as a set of dipole particles [1]. The introduced vector-function D describes density of dipole momentum. The equation for this function is in accordance with Navier-Stokes equations [2]. The vorticity is equal to curl of dipole momentum density. Thus vortex field is always solenoidal. The dipole particles are generated at a body surface and are moving interacting. The region where function D is essentially non-zero approximately coincides with the vortex region. Each dipole particle induces the velocity field which is equal to field of a point dipole at large distance from the particle. But near a particle the induced velocity field is another taking into account the particle volume and viscosity of the liquid. The method can be applied for simulation of an ideal and viscous flows

Ensuring safe descend of reusable rocket stages - Numerical simulation and experiments on subsonic turbulent air flow around a semi-circular cylinder at zero angle of attack and moderate Reynolds number

© 2017. Two-dimensional flow around semi-circular cylinder at zero angle of attack and at Re = 50000 during the self-oscillatory regime has been extensively studied within the URANS method with the use of different-structure grids (multiblock, structured overlapping, unstructured composite), the SST turbulence model and its versions (1993) and (2003) considering the streamline curvature influence modified within the Rodi-Leschziner-Isaev approach and numerical different-approximation methods realized in two codes (VP2/3, Fluent). Experiments have been made on flow around a semi-circular cylinder in the wind tunnel of the Lomonosov Moscow State University, Institute of Mechanics to obtain data for verification of numerical predictions. The double-mode character of a periodic time history of a drag force caused by a periodically forming and disappearing jet flap and acting upon a body is explained. With increasing compressibility at a Mach number ranging from 0 to 0.5, it is observed that periodic flow around the semi-circular cylinder is restructured, and the time history of the drag force acting upon it is described by a dependence close to a sinusoidal one. It is found that, as the Mach number is increased, pressure field distortions in the form of concentric cylindrical waves propagating from the semi-circular cylinder and the vortex street behind it grow over the infrasonic range

Simulation of butterfly flapping with the method of dipole domains

A numerical mesh-free method of dipole domains [1,2] is used for simulation of a butterfly flapping model. This method is based on the representation of a vortex field by the set of dipole particles. The vector function D describes density of dipole moments in accordanse with Navier-Stokes or Euler equations [3]. The butterfly model consists of two flat plates with a common edge performing harmonic oscillations in two planes. New mechanism of the thrust performing is proposed