Increasing noise regulation at urban airports force jet engine manufactures to develop and build quieter engines. Over the last 10-15 years, a significant reduction in fan and mechanical noise has been achieved. However, the reduction in jet noise over the same time period is fairly small and a major reduction in acoustic emissions of jet engines has to come from a reduction in jet noise. Tradi...

A large-eddy simulation has been performed of turbulent flow around multiple windbreaks set within a wheat canopy under neutral stability conditions. The simulation is validated against a wind tunnel data set taken under similar conditions. Velocity profiles and second-order statistics are presented and compared to those found in the wind tunnel. From the numerical simulation, we discuss spatia...

In the field of fluid engineering, controlling turbulent flows remains a crucial problem. This paper presents a basis of numerical methods and turbulence models for the large Eddy simulation. Simulation results include the unsteady analyses of complex flows, such as the vortex dynamics of turbulent jets subject to inlet perturbations and the reacting flow with flame propagation in a gas–turbine...

For jets, large eddy resolving simulations are compared for a range of numerical schemes with no subgrid scale (SGS) model and for a range of SGS models with the same scheme. There is little variation in results for the different SGS models, and it is shown that, for schemes which tend towards having dissipative elements, the SGS model can be abandoned, giving what can be termed numerical large...

the inner comer, measurements in water confirmed the formation of a counter-rotating vortex in that region. The formation of an infinite sequence of vortices near comers was first predicted by Moffat. 13 Finally, tests with the model inserted backwards in the glycerol flow confirmed that the low-Re cavity flow was essentially reversible. Because insect wings span a wide range of orientations wi...

Wall-modeled large-eddy simulation is applied to a transonic axial compressor rotor (NASA Rotor 37). The simulation results show a significant improvement over fully turbulent RANS in the prediction of the overall performance, mainly by capturing boundary layer transition on the blade. Sensitivity of the result to the end-wall boundary conditions (isothermal/adiabatic walls) and the inflow prof...