Large-Eddy Simulation of Turbulent Flow in a Pipe at Extreme Reynolds Numbers
نویسندگان
چکیده
Large-eddy simulations (LES) of turbulent flow in a smoothwall pipe at Reynolds numbers based on the pipe Radius R and wall friction velocity in the range Reτ = 2,000−2,000,000 are discussed. Using a Reynolds number based on D and the bulkflow velocity, then corresponding values are ReD = 91,800 − 165,000,000. For the LES, the spectral-element code SEMTEX was used combined with the stretched-vortex subgridscale model and a wall model. Calculated friction factors are found to be in reasonable agreement with super-pipe measurements. An estimate of the Kármán constant κ is made using a least-square fit to the friction-factor verses ReD results obtained from the LES, giving κ= 0.43.
منابع مشابه
Numerical Study of Reynolds Number Effects on Flow over a Wall-Mounted Cube in a Channel Using LES
Turbulent flow over wall-mounted cube in a channel was investigated numerically using Large Eddy Simulation. The Selective Structure Function model was used to determine eddy viscosity that appeared in the subgrid scale stress terms in momentum equations. Studies were carried out for the flows with Reynolds number ranging from 1000 to 40000. To evaluate the computational results, data was compa...
متن کاملA New Model for Prediction of Heat Eddy Diffusivity in Pipe Expansion Turbulent Flows
A new model to calculate heat eddy diffusivity in separating and reattaching flows based on modification of constant Prt is proposed. This modification is made using an empirical correlation between maximum Nusselt number and entrance Reynolds number. The model includes both the simplicity of Prt=0.9 assumption and the accuracy of two-equation heat-transfer models. Furthermore, an appropriate l...
متن کاملAerodynamic Noise Computation of the Flow Field around NACA 0012 Airfoil Using Large Eddy Simulation and Acoustic Analogy
The current study presents the results of the aerodynamic noise prediction of the flow field around a NACA 0012 airfoil at a chord-based Reynolds number of 100,000 and at 8.4 degree angle of attack. An incompressible Large Eddy Simulation (LES) turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is performed by the Ffowcs Williams and Hawkings (FW-...
متن کاملLarge-eddy simulation of turbulent flow over an array of wall-mounted cubes submerged in an emulated atmospheric boundary-layer
Turbulent flow over an array of wall-mounted cubic obstacles has been numerically investigated using large-eddy simulation. The simulations have been performed using high-performance computations with local cluster systems. The array of cubes are fully submerged in a simulated deep rough-wall atmospheric boundary-layer with high turbulence intensity characteristics of environmental turbulent fl...
متن کامل