Droplet Trajectories and Collection on Fan Rotor at Off-Design Conditions

A numerical investigation is conducted to study water droplet collection on a high bypass turbofan engine booster rotor under different rotational speeds. An Eulerian-Lagrangian approach is used in formulating the flow and droplet governing equations in the rotating reference frame. A one-way interaction model is used to model the effects of momentum and energy exchange effects with the flow on the droplets as they travel through the rotor. Results are presented for the computed flow field, droplet trajectories, water collection efficiency and droplet exit mass and temperature profiles at 60%, 70%, 80%, 90%, and 100% design rotational speeds. The highest collection is predicted near the tip at the pressure surfaces leading edge. It then drops considerably at 40%–60% of the booster rotor blade chord and remains low over the aft portion of the pressure side. In general, the rotor blade collection efficiency is strongly influenced by rotor speed and increases as the rotational speed decreases.