IPANEMA aims at developing numerical and experimental techniques for the design of inertial particle separators (IPS) in turboprop engine intakes. IPS aim at removing dust, rain, hail, ... from the main air flow by deviating it abruptly before entering the engine, such that heavier ingested particles are expelled from the main flow to a small bypass duct as they cannot follow the flow. IPS have a lower impact on engine efficiency, and can moreover be deactivated during the flight. Therefore, IPS contribute to the efficiency of the aircraft. The experimental and numerical tools for analysis of and design for separation efficiency are to date still lacking in precision, in particular for accounting for the variability in particle size. To ensure the industrial applicability of the techniques, an actual IPS will be studied during the project.
On the experimental side, the difficulties concern the injection of particles in the rig and measuring separation performance in terms of particle size. One can mention also the combination of particle measurements with measuring aerodynamic performance due to the vulnerability of the probes. A last difficulty concerns the combined detailed measurement of particle tracks and flow field in a complex geometry. On the numerical side, no methods exist that combine sufficient accuracy to an acceptable cost. Highly versatile methods based upon Lagrange particle tracking and LES, are too expensive, while Eulerian RANS based methods used in industry typically do not account well for size variability, and/or are not calibrated for flow configurations prevalent in IPS. The aim is to develop a simulation approach which offers the best compromise between geometrical flexibility, precision and cost.
Although IPS have been studied before, research was mainly targeted at assessing performance of specific geometries, whereas no significant effort is dedicated to improving models. The experimental data is typically limited to global performance, while low-cost/precision simulation approaches are used. In order to alleviate the lack of high-quality and relevant reference data for model development and physical comprehension of flow conditions prevalent in IPS, IPANEMA will publish high-resolution experimental and numerical validation data on canonical geometries.
The main conclusions are
- novel experimental and numerical capabilities have been developed that allow for a detailed analysis of the flow and aerodynamic and particle separation efficiency for both industrial and academic configurations.
- the trajectory of the larger particles, which supposedly can be evacuated easily, is mainly governed by the collision with the walls. Their ingestion depends then on the presence of dead water regions and complex recirculations, which can pick up a stationary particle.
