Title:	LES and DES for complex geometries
DNr:	NAISS 2023/5-35
Project Type:	NAISS Medium Compute
Principal Investigator:	Lars Davidson <lada@chalmers.se>
Affiliation:	Chalmers tekniska högskola
Duration:	2023-02-23 – 2024-03-01
Classification:	20306
Homepage:	http://www.tfd.chalmers.se/~lada/
Keywords:

Abstract

Aircraft noise has become an increasingly pressing topic of concern in aviation design due to its detrimental impact on people living in the vicinity of airports. Aircraft noise results from a combination of engine noise generated by the fan and the jet, and airframe noise generated by landing gear (LG) systems and high-lift devices (HLD). With the advent of quieter, ultra-high-bypass-ratio engines, airframe noise has emerged as an important contributor, particularly during approach and landing phases. Due to the complexity of noise-generation mechanisms, the mitigation of airframe noise remains to be a challenging task and has attracted intensive research efforts. In this proposed project, for the LG configuration, porous fairings are numerically investigated for the noise mitigation. The baseline LAGOON landing gear and its controlled cases with different porous fairings mounted are numerically simulated using the Improved Delayed Detached-Eddy Simulation (IDDES) in combination with the Ffowcs Williams and Hawkings (FW-H) analogy. Instead of resolving the detailed flow features through the porous fairings, a numerical model is used to represent the effect of fairing. The numerical flow fields and the far-field noise spectra are validated against the experiments conducted at Delft University of Technology. For the HLD configuration, CAA analysis will be performed on the baseline slat, reference Krueger slat and optimized slat configurations. The outcome of this project will be scientific publications and novel noise reduction techniques and best practices for the low-noise design of landing gears and high-lift devices.