Research overview
This work uses a Hybrid Lattice Boltzmann Method (HLBM) to study rigid particles suspended in homogeneous isotropic turbulence (HIT). The fluid exerts forces and torques on each particle, while the moving particle surfaces modify the surrounding flow. The project forms part of Mehmet Fazlıoğlu’s academic research experience at Middle East Technical University and is documented here as a portfolio entry.
Scientific motivation
Particle shape and orientation can affect the hydrodynamic loads on a rigid body, its rotation, and the disturbance it creates in the fluid. Freely decaying HIT provides a setting for examining these effects without imposed mean shear or sustained energy input.
Numerical methodology
The flow is simulated with an OpenLB-based framework using MPI for parallel execution. The two-way coupling uses moving particle boundaries and evaluates hydrodynamic force and torque for six-degree-of-freedom rigid-body motion, including translation and rotation.
DNS initialization and free decay
A velocity field generated by pseudo-spectral direct numerical simulation (DNS) initializes the HLBM flow at t = 0. The HLBM solver then evolves the flow as freely decaying turbulence, with no continued exchange with a DNS solver and no sustained turbulence forcing.
Research objectives
- Examine how finite-size, non-spherical and irregular particles affect the evolving turbulent flow.
- Assess how particle geometry and orientation influence hydrodynamic forces, torques and rigid-body motion.
- Establish a verification procedure for the initialization, particle dynamics and coupled simulation.
Development and validation
The development work addresses initialization from the DNS velocity field, parallel execution, and the rigid-body update for irregular particle geometry. Verification targets include the initial field after transfer, decay in a particle-free baseline, rigid-body rotation, force and torque evaluation, and sensitivity to spatial and temporal resolution.
Research status
Ongoing academic research at METU.