%0 Journal Article %A Krasheninnikov, Sergei Yu. %A Lyubimov, Dmitriy Aleksandrovich %A Mironov, Aleksey Konstantinovich %A Pudovikov, Dmitriy Evguenyevich %A Toktaliev, Pavel Damirovich %D 2014 %I Begell House %K numerical simulation, spatial unsteady flows, turbulence, RANS, URANS, LES, acoustic waves %N 3-4 %P 183-213 %R 10.1615/TsAGISciJ.2014011734 %T EXAMPLES OF NUMERICAL SIMULATION OF COMPLEX TURBULENT FLOWS AND ACCOMPANYING PROBLEMS %U https://www.dl.begellhouse.com/journals/58618e1439159b1f,5896a16360613483,54d14e64311f2273.html %V 45 %X Numerical solutions to the steady Reynolds-averaged Navier−Stokes (RANS) and unsteady RANS (URANS) equations with phenomenological turbulence modeling and full unsteady Navier−Stokes equations are obtained for complex flows, in which the important characteristics are turbulence, unsteady behavior, three-dimensionality, instability development, existence of acoustic effects, etc. A series of problems are solved, which are addressed to not only determine specific parameters of the considered complex flows, but also to analyze their features, which cannot be simulated by numerical methods, or new features, that were unknown before the current investigation. Numerical simulation of a vortex flow that arises during aeroengine operation near the ground was performed based on the solutions to the Reynolds equations. The numerical simulation showed that external particles are sucked into the air intake by the vortex through ejection of small particles from the vortex and their subsequent accumulation at the base of the vortex, where a high-density dust particle medium is formed. Numerical simulation of a separated flow in a curved annular diffuser was performed based on the RANS, URANS, and large eddy simulation (LES) approaches. Simultaneously, experimental research was carried out on the models. In both the simulations and experiments, zones of nonuniformity were detected and unsteady and three-dimensional types of flow were observed. However, the average flow field at the diffuser exit was found to be axisymmetrical. The flow simulation and experiments for a strongly swirling jet showed that the flow in the jet is fundamentally unsteady and three-dimensional and can be classified as steady and two-dimensional only on average. Numerical simulation of a flow in a turbulent jet behind the chevron nozzle based on the RANS technique allowed detecting vortex structures generated by chevrons and determining the intensity of the longitudinal vorticity, in which the values agreed with the acoustic measurements. A formulation of the initial conditions for the numerical solution of the unsteady Navier−Stokes equations is proposed for the simulation of flows in turbulent jets near the nozzle edge. The proposed initial conditions allow the process of mixing layer development near the nozzle edge to be simulated with appropriate accuracy. %8 2014-12-05