The study provided a base of comparison of known computational techniques with different fidelity levels for performance and noise prediction of a single, fixed-pitch UAV rotor operating with varying flight parameters. The range of aerodynamic tools included blade element theory, potential flow methods (UPM, RAMSYS), liftingline method (PUMA) and N...
In this paper, an hp-adaptation strategy designed for discontinuous Galerkin methods is applied to hybrid RANS/LES simulations. The 3D hp-adaptive strategy is suited for tetrahedral and hybrid prismatic/tetrahedral meshes, and relies on a metric-based remeshing approach. The metric field and the polynomial map of the adapted meshes are built from a...
The analysis of the influence of various design solutions of the gas-dynamic stabilization system in plasma torches for cutting metals on the efficiency of equalizing the velocities of gas flows along the cross-section of the gas path is carried out. It is noted that the efficiency evaluation method developed by the authors should be based on the c...
Two- and three-dimensional models representative of a helicopter rotor blade element during forward flight have been implemented. The rotor blade element is considered in pitching oscillation motion with a non-uniform translation to take into account the speed variation in forward flight. Two stalled flight conditions of the 7A rotor have been sele...
The results of the efficiency studies of gas-vortex stabilization systems for metal-cutting plasmatrons are presented. It is noted that the method of efficiency evaluation developed by the authors should be based on the calculation of the uniformity of the gas flow velocity distribution over the section of the gas-heating path of the plasma torch. ...
Influence of gas distribution uniformity in the channels of air-gas paths on efficiency and quality of metals cutting is noted for plasmatrons of various updating. It is shown, that application of gas-dynamic filters promotes efficiency and quality of plasmatrons with the one-line scheme of air-gas pathswork. The technique for estimation of gas dis...
Published in Physical review. E
Molecular dynamics simulations of flow between concentric rotating cylinders are performed. As the relative speed between the two cylinders is increased, a spontaneous flow bifurcation occurs and vortices form in a stationary-vortex or traveling-wavy-vortex configuration. The former emerges when the axial boundary conditions constrain the flow by r...
Several designs of plasma torches for cutting of metals are used to analyse the effect of design special features of the gas-air circuit on the efficiency of operation of the gas vortex stabilisation system. It is shown that the distribution of the flows of the plasma-forming gas in the cross section of the circuit is non-uniform. A method of stabi...
The effect of different design solutions of the system of gas vortex stabilization of plasma torches for cutting of metals on the efficiency of equalization of the speed of the gas flows in the cross section of the gas circuit is analysed. The results of synthesis of the proposed solutions are used to design and optimize a new gas vortex system wit...
Collective transverse plasma modes in Bi2Sr2CaCu2O8+x, intrinsic Josephson junctions (IJJs) can be excited by the moving fluxon lattices. Progressive transformation of the standing-wave-like fluxon-lattice configuration from a triangular lattice to a rectangular lattice takes place as the dynamic fluxon-lattice modes are in resonance with the colle...
