Publications

Version: 1.0 Approved

LDO-ID 2022PUB00104

Title Adaptive Design Method for a Tilt-Rotor Engine Inlet Duct Optimization

Abstract

An adaptive design methodology is presented involving an inverse design to obtain the most possible favorable pressure field in an engine intake duct. A cost functional measuring the deviation between an actual and a desired pressure distribution is to be minimized. A gradient-based optimization algorithm is deployed, where the gradient is calculated by means of the adjoint method. The intake duct has a non-conventional shape that is dictated by an innovative transition mechanism from VTOL to cruise condition (and vice versa) where the position of the engine is kept fixed during tilting of the rotor. The initial design of the duct was rather more dictated by system constraints. Aerodynamically, it features a large distortion on the engine Aerodynamic Interface Plane (AIP) with strong flow unsteadiness. Geometrically, there is a stringent constraint where certain features of the topology of the geometry need to be preserved. An adaptive optimization approach is followed, involving an integrated process from simulation of the complete tilt-rotor configuration for the pre- and post-optimization analyses, to an isolated duct configuration suitable for the design optimization process. The complete configuration includes the rotating blades with rigid pitch-flap motions, nacelle, spinner and wing. The consistency between the complete and isolated domain is ensured by applying proper boundary conditions on the interface between the two domains. The paper will describe the design methodology, process and results in more detail. NLR’s CFD code ENFLOW is used throughout the analysis and inverse design process.

Authors Soemarwoto, Bambang I.; Habing, Remco; Pecoraro, Matteo

Type Paper for Seminar/Symposium/Conference

Media AIAA Aviation Forum (27 June - 01 July 2022, Chicago, IL, USA)

Web site

https://virtualaviation.aiaa.org/Title/9383a6e3-52b1-461a-b02b-a3be71fee800

Anno 2022