Performance Prediction of Inlet Barrier Filter Systems for Rotorcraft


European Rotorcraft Forum

N Bojdo & A Filippone
European Rotorcraft Forum
May 2011

An insight into the design parameters that dictate Engine Inlet Barrier Filter (IBF) performance is presented. The work represents the first part of a two part study into the factors affecting the performance of IBF, to ultimately enable the prediction of turboshaft engine performance during use of this air-particle separating device. The problem is initially described, and is followed by a parametric study to ascertain the effect of pleat shape, turbulence and inflow velocity on overall pressure drop across a pleated filter for IBF. It is shown that turbulence has little effect on IBF performance, while an increase in pleat count and inflow velocity both result in a larger pressure drop across the filter. The results are explained by analysis of the flow. A discussion of the possible consequences of pleat shape on the three IBF performance indicators (pressure drop, holding capacity and collection efficiency) is also given. Finally, a formula is provided to ascertain the pressure drop across a given pleated filter in a given flow.