Explanipedia

Airframe noise simulation of an A320 aircraft in landing configuration Open

Stan Proskurov, Michael Moessner, Roland Ewert, Jan Delfs, Juergen Dierke , et al. · 2025

The high-lift system noise is predicted for a landing approach condition for the actual scale Airbus 320-232 “D-ATRA” research aircraft of DLR. Noise simulations are performed for all key elements of the high-lift wing using stochastically…

A quantity to identify turbulence related sound generation on surfaces Open

Jan Delfs, Richard Ruck · 2024

This contribution addresses the problem of identifying sources of sound on aerodynamic surfaces subject to turbulent flow. A quantity is proposed, which identifies the location of the sound generation and serves as well to quantify these s…

Installed Fan Noise Simulation of a Supersonic Business Aircraft Open

Stan Proskurov, Markus Lummer, Jan Delfs, Roland Ewert, Jochen Kirz , et al. · 2023

Overcoming the problem of excessive engine noise at low altitudes is a formidable task on the way to developing a supersonic passenger aircraft. The focus of this paper is on the fan noise shielding during take-off, investigated as part of…

A Quantity to Identify Turbulence Related Sound Generation on Surfaces Open

Jan Delfs · 2023

Extension of the concept of Ffowcs-Williams and Hawkings type wave extrapolation to non-trivial flow effects and exterior surfaces Open

Jan Delfs, Michael Mößner, Stanislav Proskurov, Roland Ewert · 2022

In appreciation of Ffowcs-Williams and Hawkings’ seminal contribution on describing the sound radiation from moving objects, this article discusses a concept of taking into account local non-trivial flow effects on the sound propagation. T…

Sound shielding simulation by coupled discontinuous Galerkin and fast boundary element methods Open

Stan Proskurov, Roland Ewert, Markus Lummer, Michael Mößner, Jan Delfs · 2022

A code coupling has been established for performing efficient fan tone shielding simulations of aerial vehicles with unconventional engine installations. In particular, the Fast Multipole Boundary Element Method (FM-BEM) which is formulate…

Correction: Impedance boundary condition in frequency domain DG code for modelling liner effects in complicated intake ducts Open

Stanislav Proskurov, Michael Moessner, Jan Delfs · 2022

Aeroacoustics research in Europe: The CEAS-ASC report on 2020 & 2021 highlights Open

Attila Nagy, Jan Delfs, Gareth J. Bennett · 2022

In 2012, DLR has initiated an international working group in the area of overall aircraft noise prediction between NASA, ONERA, and DLR. The main goal of the group was to compare their simulation tools and to establish common ground in tha…

What drives noise from UAV vehicles, what about noise reduction Open

Jan Delfs · 2020

Propeller Noise reduction for E-drives, \nnoise reduction potential E-driven propulsors are indirect

DLR's Laser Sound Source, a Status Review Open

Karl-Stéphane Rossignol, Jan Delfs, Michaela Herr · 2020

Because of the growing interest in noise abatement through the shielding of aircraft component noise (including \nengine noise), there has been, in the past few years, an increased necessity for the development of appropriate \nevaluation …

Aeroacoustic Assessment of Low-Observable UCAV Configurations Open

Karl-Stéphane Rossignol, Stanislav Proskurov, Markus Lummer, Roland Ewert, Jan Delfs , et al. · 2020

First, results of experimental and numerical investigations on generic engine noise shielding by the SACCON \nUCAV configuration are presented. The results suggest that propulsion system intake noise is much less \nattenuated compared to e…

Noise Prediction within Conceptual Aircraft Design Open

Lothar Bertsch, Sébastien Guérin, Jan Delfs, Markus Lummer · 2020

Motivation for the presented activities is the integration of noise as an additional objective in conceptual aircraft design. Therefore, the Parametric Aircraft Noise Analysis Module (PANAM) is developed to account for individual noise sou…

Effect of Porous Materials on the Acoustic Emissions of a Circulation-Control High-Lift Airfoil Open

Karl-Stéphane Rossignol, Lennart Rossian, Alexandre Suryadi, Michaela Herr, Roland Ewert , et al. · 2020

Slat Noise Prediction of a Full Scale Aircraft and Validation with Flight Test Data Open

Nils Reiche, Markus Lummer, Michael Pott-Polenske, Roland Ewert, Jan Delfs · 2020

10 years of joint research at DLR and TU Braunschweig toward low-noise aircraft design-what did we achieve? Open

Lothar Bertsch, Wolfgang Heinze, Sébastien Guérin, Markus Lummer, Jan Delfs · 2019

This review article is based on an invited keynote presentation at the 22ndWorkshop of the Aero acoustics Specialists Committee of the CEAS. The event was held in September 2018 in Amsterdam with the main focus on the relation between airc…

Beamforming for point force surface sources in numerical data Open

David Evans, Michael Hartmann, Jan Delfs · 2019

In this paper, a method based on conventional beamforming for the localisation of point force surface sources in numerical data is presented. The method is designed specifically for numerical beamforming by taking advantage of the freedom …

Efficient prediction of broadband trailing edge noise and application to porous edge treatment Open

Benjamin Faßmann, Christof Rautmann, Roland Ewert, Jan Delfs · 2018

Trailing edge noise generated by turbulent flow traveling past an edge of an airfoil is one of the most essential aeroacoustic sound generation mechanisms. It is of great interest for noise problems in various areas of industrial applicati…

Experimental Investigations on Noise Shielding: Dependency on Reference Noise Source and Testing Environment Open

Karl-Stéphane Rossignol, Jan Delfs, Michael Mößner, Denis Gély, Jean Bulté , et al. · 2018

This paper presents the experimental results of a study conducted at DLR, ONERA and NASA on the shielding of sound by an NACA 0012 airfoil. The work presented was done in the context of the AVT-233 working group of the Science and Technolo…

Aircraft Noise Assessment—From Single Components to Large Scenarios Open

Jan Delfs, Lothar Bertsch, Christoph Zellmann, Lennart Rossian, Ehsan Kian Far , et al. · 2018

The strategic European paper “Flightpath 2050” claims dramatic reductions of noise for aviation transport scenarios in 2050: “...The perceived noise emission of flying aircraft is reduced by 65%. These are relative to the capabilities of t…

Needs for future experimental testing in Aeroacoustics Open

Jan Delfs · 2018

Future challenges in aircraft noise are discussed and requirements are derived for future aeroacoustic testing in wind tunnels. Concepts for a more synergistic use of acoustic measurements and numerical simulations are presented with first…

Installation effects of a propeller mounted on a wing with Coanda flap Open

Jürgen Dierke, R.A.D. Akkermans, Jan Delfs · 2015

The effect of installation on propeller noise was investigated. The chosen configuration consists of a nine bladed propeller in tractor configuration with a high-lift wing. Tests in the 3m acoustic wind tunnel DNW-NWB provided a valuable d…

Prediction of Porous Trailing Edge Noise Reduction via Acoustic Perturbation Equations and Volume Averaging Open

Benjamin Faßmann, Christof Rautmann, Roland Ewert, Jan Delfs · 2015

Edge noise is generated if turbulence interacts with solid edges. Reduction of trailing edge noise of airfoils can be achieved by replacing the solid material at the trailing edge by inlays of porous permeable material. The acoustic benefi…

Large-Scale Studies on Slat Noise Reduction Open

Michaela Herr, Michael Pott-Pollenske, Roland Ewert, Dirk Boenke, Jona Siebert , et al. · 2015

Slat noise research activity within the EC co-financed project OPENAIR involved both experimental and numerical studies at the new large (1:3.3-scaled) swept high-lift wing \nmodel F15LS. Experiments were performed in the DNW-LLF (Large Lo…

Derivation of Volume Averaged Perturbation Equations for Aeroacoustics in Porous Materials Open

Benjamin Faßmann, Jan Delfs, Roland Ewert · 2015

The derivation of a set of volume averaged perturbation equations is presented. The new governing equations allow predicting the effect of open type porous materials on the aeroacoustics of side or trailing edges of airfoils. The numerical…

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