Tillage has long been an essential component of traditional agricultural systems. Broadly defined, tillage is the mechanical manipulation of the soil and plant residues to prepare a seedbed for crop planting. The benefits of tillage are many: it loosens soil, enhances the release of nutrients from the soil for crop growth, kills weeds, and regulates the circulation of water and air within the s...

Abstract To further develop a more effective turbulence model and improve the calculation accuracy of flow, new was constructed using deformation rate tensor, grouping average. Due to need evaluate applicability in numerical calculation, flow around NACA0012 airfoil with Mach number 0.15 multiple angles attack calculated on OpenFOAM platform based grid independence research. The Spalart-Allmara...

We report research experience in applying an Unsteady Reynolds-Averaged Navier-Stokes (URANS) solver for the prediction of time-dependent flows in the presence of an active flow control device. The configuration under consideration is a synthetic jet created by a single diaphragm piezoelectric actuator in quiescent air. Time-averaged and instantaneous data for this case were obtained at Langley...

Abstract This paper compares the performance of four low-Reynolds-number models for the unsteady Reynolds-averaged Navier-Stokes equations applied to the flow in a channel driven by a pressure gradient oscillating around a non-zero mean. The models considered are the one-equation Spalart-Allmaras model, the k − ε model with the wall functions of Lam and Bremhorst, the k−ω model of Saffman and W...

Abstract: Detached-eddy simulation (DES) based on the v-f Reynolds-averaged Navier-Stokes (RANS) model is developed and tested. The v-f model incorporates the anisotropy of near-wall turbulence, which is absent in other RANS models commonly used in the DES community. The v-f RANS model is modi ed in order that the proposed v-f -based DES formulation reduces to a transport equation for the subgr...

We present a practical approach for the numerical solution of the Reynolds averaged Navier-Stokes (RANS) equations using high-order discontinuous Galerkin methods. Turbulence is modeled by the Spalart-Allmaras (SA) one-equation model. We introduce an artificial viscosity model for SA equation which is aimed at accommodating high-order RANS approximations on grids which would otherwise be too co...

In the present work, flow field is analysed for Mach number, pressure and temperature in 2D computational domains a planar nozzle of symmetrical geometry as used experimental tests cold (air) flow. The study has been considered three mean angles divergent section: α = 9°, 11.01° 13°, four ratios: NPR 2.412, 3.413, 5.423 8.78. For numerical simulation turbulence presence shock waves, RANS model,...

The paper presents computational prediction of aerodynamic hysteresis loops in static conditions for a two-dimensional aerofoil that was used as cross-section profile rectangular wing with an aspect ratio five, tested the TsAGI T-106 wind tunnel at Reynolds number and Mach . Tests showed minor changes curvature leading edge thin lead to significant increase maximum lift coefficient when appear ...

A significant extension of previously introduced continuous eddy simulation methods is presented by introducing minimal error partially and fully resolving for turbulent flows. This approach represents a machine learning strategy the hybridization modeling-focused resolution-focused methods. It can be applied to well-known equation structures (Spalart–Allmaras type equations, usually two-equati...