Search results for "Reynolds equation"

showing 3 items of 3 documents

Large eddy simulations on the effect of the irregular roughness shape on turbulent channel flows

2019

Abstract Large Eddy Simulations (LES) are carried out to investigate on the mean flow in turbulent channel flows over irregular rough surfaces. Here the attention is focused to selectively investigate on the effect induced by crests or cavities of the roughness. The irregular shape is generated through the super-imposition of sinusoidal functions having random amplitude and four different wave-lengths. The irregular roughness profile is reproduced along the spanwise direction in order to obtain a 2D rough shape. The analysis of the mean velocity profiles shows that roughness crests induce higher effect in the outer-region whereas roughness cavities cause the highest effects in the inner-reg…

Higher order statisticMaterials scienceTurbulence simulationTurbulent channel flows Large eddy simulation02 engineering and technologyReynolds stressSurface finish01 natural sciencesReynolds numberSettore ICAR/01 - Idraulica010305 fluids & plasmasPhysics::Fluid Dynamicssymbols.namesake0203 mechanical engineering0103 physical sciencesMean flowReynolds equationAnisotropyChannel flowFluid Flow and Transfer ProcessesTurbulenceMean velocity profileMechanical EngineeringIrregular roughneReynolds numberSinusoidal functionMechanicsCondensed Matter PhysicsOpen-channel flowShear stre020303 mechanical engineering & transportsAmplitudeReynolds streTurbulence Irregular shapeTurbulence intensityLESsymbolsTurbulence modulationInternational Journal of Heat and Fluid Flow
researchProduct

High Reynolds number Navier-Stokes solutions and boundary layer separation induced by a rectilinear vortex array

2008

Numerical solutions of Prandtl’s equation and Navier Stokes equations are considered for the two dimensional flow induced by an array of periodic rec- tilinear vortices interacting with an infinite plane. We show how this initial datum develops a separation singularity for Prandtl equation. We investigate the asymptotic validity of boundary layer theory considering numerical solu- tions for the full Navier Stokes equations at high Reynolds numbers.

PhysicsPrandtl numberMathematical analysisMathematics::Analysis of PDEsReynolds numberNon-dimensionalization and scaling of the Navier–Stokes equationsunsteady separationReynolds equationPhysics::Fluid DynamicsFlow separationsymbols.namesakeBoundary layerPrandtl equation interactive viscous–inviscid equation.Navier Stokes solutionsymbolszero viscosity limitNavier–Stokes equationsReynolds-averaged Navier–Stokes equationsSettore MAT/07 - Fisica Matematica
researchProduct

Numerical and experimental study of hydrostatic displacement machine

2012

This paper presents a simulation tool to determine the structural deflections and corresponding leakage flow in a hydrostatic displacement motor. The simulation tool is applied to a new motor principle that is categorized as an extreme low-speed high-torque motor with dimensions that calls for attention to the volumetric efficiency. To counteract structural deflections the motor is equipped with compensation pressure volumes that may be used to limit the leakage flow across the end faces of the circular rotor. This leakage flow is investigated by solving Reynolds equation for the pressure distribution across both end faces. The fluid pressure is combined with structural calculations in a fl…

Volumetric efficiencyEngineeringbusiness.industryMechanical EngineeringGeneral Physics and AstronomyLeakage flowStructural engineeringHigh torqueReynolds equationlaw.inventionPhysics::Fluid DynamicsLow speedlawFluid–structure interactionHydrostatic equilibriumbusinessLeakage (electronics)
researchProduct