**Two-Fluid RANS-RSTM-PDF Model for Turbulent Particulate Flows**

P. Lauk, A. Kartushinsky, M. Hussainov, A. Polonsky, Ü. Rudi, I. Shcheglov, S. Tisler and K.-E. Seegel

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/63338

#### **Abstract**

A novel three-dimensional (3D) model based on Reynolds turbulence stress model (RSTM) closure of equations of carrier and particulate phases was elaborated for channel turbulent flows. The essence of the model is the direct calculation of normal and shear components of the Reynolds stresses for the particulate phase similar to the carrier fluid. The model is based on the Eulerian approach, which is applied for the 3D RANS modeling of the carrier flow and the particulate phase and the statistical probability dense function (PDF) approach focusing on the mathematical description of the second moments of the particulate phase.

The obtained numerical results have been verified and validated by comparison with experimental data obtained on turbulent dispersion of solid particles ejected from point source for turbulent uniform linear shear flow. Two cases of spatial orientation of shear of the flow mean velocity were examined: in the direction of gravity and in the direction perpendicular to gravity. Numerical data on turbulent dispersion of particles and spatial displacement of the maximum value of the concentration distribution show satisfactory agreement with experimental results.

**Keywords:** turbulent channel flows, solid particles, closure equations, PDF of particu‐ late phase velocity, shear flow
