turbulent fluxes in the atmospheric boundary layer are calculated using different models. one of the most popular and operational models in this groundwork is the second order turbulent model of mellor and yamada that has been widely used to simulate the planetary boundary layer (pbl). despite its popularity, it has been shown that this model has several weeknesses that affect its accuracy. the...

The turbulent potential model is a RANS model that avoids modeling the Reynolds stress tensor. As a result it has the ability to obtain the physical accuracy of Reynolds stress transport equation models at a cost and complexity comparable to popular two equation models. The model’s ability to predict channel flow, free-shear layers, homogeneous shear flow, stagnation point flow, backward facing...

The design and optimization of hydrocyclones using CFD techniques are gaining popularity and the key to a successful simulation lies with the accurate description of the high turbulent swirling behavior of the flow. This paper presents a detailed co...

Several rigorous turbulent models have been developed in the past years and it can be seen that more research is needed to reach a better understanding of their generality and precision by verifying their applications for distinct hydraulic phenomena; under certain assumptions. This survey evaluates the performance of Standard k-ε, Realizable k-ε, RNG k-ε, k-ω and RSM models in predicting flow ...

Title Numerical visualization of boundary layer transition when negative Magnus effect occurs Author(s) Muto, Masaya; Tsubokura, Makoto; Oshima, Nobuyuki Citation Journal of Visualization, 15(3): 261-268 Issue Date 2012-08 DOI Doc URL http://hdl.handle.net/2115/53053 Right The original publication is available at www.springerlink.com Type article (author version) Additional Information File Inf...

Visualizations of Rayleigh–Taylor turbulent mixing layers are presented. Three Navier–Stokes models are used: Boussinesq, anelastic and fully compressible. Isosurfaces and slices of concentration, vorticity, Q-criterion, turbulent kinetic energy, local Taylor-microscale Reynolds number, dissipation, pressure and temperature are displayed. This gives an overall picture of the Rayleigh–Taylor flo...

We demonstrate that nonlocally coupled limit-cycle oscillators subject to spatiotemporally white Gaussian noise can exhibit a noise-induced transition to turbulent states. After illustrating noise-induced turbulent states with numerical simulations using two representative models of limit-cycle oscillators, we develop a theory that clarifies the effective dynamical instabilities leading to the ...

Information theory provides a concise systematic framework for measuring climate consistency and sensitivity for imperfect models. A suite of increasingly complex physically relevant linear Gaussian models with time periodic features mimicking the seasonal cycle is utilized to elucidate central issues that arise in contemporary climate science. These include the role of model error, the memory ...

The acoustic power injected by turbulent convection into solar-like oscillations depends on the details of the turbulent spectrum. A theoretical formulation for the oscillation power is developed which generalizes previous ones. The formulation is first calibrated on a solar model in such a way as to reproduce the solar seismic data. This allows to investigate different assumptions about the st...

Lattice Boltzmann method (LBM) has become an alternative method of computing a variety of fluid flows, ranging from low Reynolds number laminar flows to highly turbulent flows. For turbulent flows, non-uniform grids are preferred. Taylor series expansionand least-squares-based LBM (TLLBM) is an effective and convenient way to extend standard LBM to be used on arbitrary meshes. In order to show ...