Hibrit sonlu-hacim/partikül metodu ile tepkimesiz döngülü akışlar üzerine hesaplamalı çalışma

This thesis computationally examines the flow characteristics of a non-reacting swirling bluff-body turbulent flow by the velocity-turbulent frequency PDF method to show the performance of the PDF method for such flows. This is the first step in performing full PDF computations of the swirling combustors and lays foundation for future work in which reacting case will be studied. In PDF method, the transport equation for mass-weighted joint PDF is directly derived from the Navier-Stokes equations and the unclosed terms are modeled through construction of stochastic differential equations (SDEs). The closure is usually guided by existent Reynolds stress models such that the joint PDF model is equivalent to the corresponding Reynolds stress model at the second moment level. The modeled PDF evolution equation is solved using a finite-volume/particle-based Monte Carlo method. The statistical stationarity of simulations is demonstrated and the computational results are compared with the experimental data. It is found that there is a reasonably good agreement between the computational and experimental results especially for the axial mean velocity and Reynolds stresses. However the prediction of the tangential mean velocity component is found to be poor indicating that the current hybrid algorithm needs further improvements.