Abstract:
Stagnation point flows with particles are commonly found in chemical pipe transportation, rocket combustion chambers, and aeroengines, etc. The development of reliable predictive models for practical industrial problems requires full understanding of particle dynamics in such flows. Therefore, particle dynamics in a stagnation point flow was investigated by means of a Particle-Resolved Direct Numerical Simulation (PR-DNS). It is found that the dynamics of a single finite
- size neutrally-buoyant particle in a stagnation point flow is unusual. When the particle is far from the wall, it behaves as a fluid tracer, regardless of its finite size and inertia,
while near the wall, such a fluid-tracer behavior disappears. A time
- adaptive wet collision model reflecting real physical properties has been developed. The empirical parameter-tuning is not necessary for this model. Results indicate that
the particle inertia is the crux of the particle-wall interaction, and that the inviscid ambient pressure,
which is unique in stagnation point flows, plays a key role in the unusual contactless bouncing.