Inertial Particle Separators: Experiments, Simulations, and Design Insights

Gas turbine engines can be subject to damage from ingesting dust, ash, and debris. This can result in increased maintenance costs, downtime, and even engine failure. An inertial particle separator (IPS) is an inlet-mounted device that can remove sand, dust, and other harmful material from the engine flowpath. This system can minimize particulate ingestion during helicopter landings in austere brown-out conditions, increasing engine life and aircraft survivability. Typically, IPS systems have lower engine power losses than alternative engine inlet filtration technologies.

This study assembled the largest publicly available dataset of IPS wind tunnel experiments. New flowpath geometries, test dusts, and flow conditions were evaluated, and a model of general IPS design was created. Additional empirical models for irregular particle bounce and drag behaviors were developed.

The first unsteady simulations of an IPS were conducted. The results showed the presence of prominent secondary flows and massive flow separation in both inlet ducts and demonstrate the numerical method’s ability to replicate the experiments. Particle trajectories were simulated, and results were within the range of experimental error for predicting particle separation efficiency. The validated numerical model confirmed that flow unsteadiness plays a key role in IPS behavior.
To demonstrate the general extensibility of the new methodologies, a hypersonic vehicle traveling through a volcanic ash cloud was also simulated. Particle trajectories using the newly developed drag model were used to create a damage prediction model to increase vehicle survivability.