in this research, the numerical method of computational fluid dynamics and dimensionless parameter of froude number have been applied to determine the flow regime over ogee spillways.froude number is a dimensionless dynamic parameter calculated using the square root of the ratio of inertia force and gravitational force. considering that the study of the regimes of flow over hydraulic structures...

We propose a natural stretching function for DNS of wall-bounded flows, which blends uniform near-wall spacing with resolution in terms Kolmogorov units the outer wall layer. Numerical simulations pipe flow are used to educe optimal value blending parameter and grid guarantee accuracy computational efficiency as results maximization allowed time step. Conclusions supported by carried out at suf...

Flow resistance, velocity distribution, and turbulence intensity are significantly influenced by aquatic vegetations (AV) in riparian zones. Understanding the hydraulics of flow with planted floodplains is great significance for determining distribution profile supporting fluvial processes management. However, traditional flume experiment method inefficient. Therefore, multigroup simultaneous t...

the technique used to control the airflow is based on the electro-hydrodynamic actuator which is also called plasma actuator. this actuator ensures the airflow control thanks to the electric wind created by the electrical corona discharge. this ionic wind is developed at the profile surface tangential to the initial free airflow so that it has a significant effect on the boundary layer flow. th...

The friction coefficient was measured for developed flow of drag-reducing polymer solutions in tubes of 2, 5, 10, 20 and 52 mm i.d. Our results were processed along with other authors' data in terms of different parameters in order to investigate the possibility of developing a simple empirical method for the prediction of the pipe diameter effect on friction. We found that the drag-reduction c...

The dynamics of fully developed hydrodynamic turbulence still is a basically unsolved theoretical problem, due to the strong-coupling long-range nonlinearities in the Navier-Stokes equations. The present analysis focuses on the small-scale fluctuations in a turbulent boundary layer with one external length scale y(o). After taking a (2+1)D spatiotemporal spectral transform of the fluctuating vo...

The in situ permeability of a formation is obtained by the inversion of Stoneley wave phase velocity and attenuation, which are evaluated by applying the Extended Prony's method to the array sonic logging data. The Maximum Likelihood inversion is used together with logarithmic parameterization of the permeabilities. Formation shear wave velocity is also inverted for. This process is tested on b...

The statistical properties of wall turbulence in the logarithmic region are investigated using structure functions of the streamwise velocity. To this end, datasets that span several orders of magnitude of Reynolds numbers are used, up to Reτ = O(106), providing uniquely large scale separations for scrutinising previously proposed scaling laws. For the second-order structure functions strong su...

Dark matter (DM) halos formed in CDM cosmologies seem to be characterized by a power law phasespace density profile. The density of the DM halos is often fitted by the NFW profile but a better fit is provided by the Sersic fitting formula. These relations are empirically derived from cosmological simulations of structure formation but have not yet been explained on a first principle basis. Here...

The technique used to control the airflow is based on the electro-hydrodynamic actuator which is also called plasma actuator. This actuator ensures the airflow control thanks to the electric wind created by the electrical corona discharge. This ionic wind is developed at the profile surface tangential to the initial free airflow so that it has a significant effect on the boundary layer flow. Th...