in this paper, inflow turbulence effects on the flow wake parameters around a naca0012 airfoil at zero incidence angle and reynolds number of 38,700 were investigated. various turbulence promoter networks were used to achieve turbulence intensity of 5% and 6%. experiments have been conducted for three different turbulence intensities in which mean velocity parameters, turbulence intensity, freq...

recognizing of river flow pattern, deposition and erosion areas in meanders is highly important. despite the limitations of the physical models in laboratory investigation of flow pattern in meanders, mathematical models can be helpful. in this research, rsm and les turbulence models have been compared on sharp river bend of a laboratory flume using fluent software. the laboratory flume is a sh...

A full scale physical model of a thin slab caster with a four-hole design submerged entry nozzle (SEN) was constructed. On the basis of the dimensionless Reynolds and Froude similitude criteria, the fluid flow in a full-scale model is similar to that of the actual system and, hence, the data obtained from the water model can be applied to the actual system. In order to determine the optimum ope...

The presence of wall strengtheners in double-stage electrostatic precipitators affects gas velocity, electrical field and particle movement over the ESP. In this work we have used our previous mathematical model for double-stage ESP {Talaie et. al (2001) [10]] to study the effect of wall strengtheners on the performance of double-stage ESP. One of the important findings was that, due to the fac...

The aim of the current work is to investigate a series of new subgrid models by employing the Kolmogorov equation of ltered quantities (KEF), which is an exact relation of turbulence in physical space. Di erent formulations of KEF are derived, including the forms in velocity eld (homogeneous isotropic turbulence, inhomogeneous anisotropic turbulence, homogeneous shear turbulence, homogeneous ro...

Using experimental models along with conducting numerical analysis have been widely used in performance recognition and optimization of hydraulic equipments. Numerical modeling has lower cost rather than experimental one; however practical tests are commonly used because of the hydraulic structure importance especially in dams. Meanwhile numerical methods could be used for future designs throug...

on the source of plasma density and electric field perturbations in pmse and pmwe regionspolar mesospheric summer/winter echoes (pmse/pmwe) are very strong radar echoes produced by ionospheric electron density fluctuations at half the radar wavelength. the main focus of this paper is the altitude range 80 to 90 km in summer and altitude range 65-86 km in winter in the polar mesosphere . this pa...

simulation of turbulence boiling, generation of vapour and predication of its behaviour are still subject to debate in the two-phase flow area and they receive a high level of worldwide attention. in this study, a new arrangement of the three dimensional governing equations for turbulence two-phase flow with heat and mass transfer are derived by using ensemble averaging two-fluid model and util...

The effects of anisotropic turbulence on the wander and spreading of Gaussian-Schell model beams propagating in non-Kolmogorov marine-atmospheric channel are investigated. Expressions for beam wander and long-term beam spreading are derived in all conditions of marine-atmospheric turbulence. Our results indicate that the beam wander and spreading of Gaussian-Schell model beams are lower in the ...