1. Mid-Term Report Fellow’s Presentation Jonathan Tournadre
Keele University /09/2014
Mid-Term Report Fellow’s Presentation Jonathan Tournadre

2. Outline Introduction of the fellow1
Introduction of the fellow 2
Research task motivation and objectives 3
Research achievements and future plans 4
Technical and complementary skills development 5
Networking

3. Numerical study of perforated plates with grazing and bias flow
Who am I?
PhD student enrolled at the KU Leuven, in the Mechanical Engineering faculty.
Work at Siemens (former LMS International), in the 3D simulation division.
Part of the TANGO Project on Research Task 1.3
Numerical study of perforated plates with grazing and bias flow

4. Resonator array to attenuate tonal noise, combustion chamber orifices
Motivations and goals of research task
Better understand the physics of sound-flow interaction for perforates
Gain better modeling/simulation capability for structures with perforations
Applications:
Resonator array to attenuate tonal noise, combustion chamber orifices
Figure: Orifice structures in gas turbine.
Figure: Honeycomb structure of SDOF locally reacting liner.

5. Motivations and goals of research task
Some of the challenges:
Various flow conditions:
Grazing flow, bias flow, mixed.
Work done previously
Scale-resolving simulations such as Direct Numerical Simulation (DNS)
Semi-empirical models
Computationally costly
Limited validity range

6. Accurate simulation of flow/sound interaction for perforate structures
From the comprehension of local phenomena …
Increased reliability in impedance modelling
Numerical Hybrid Methodology
Development of Linearized Navier Stokes Equations solver
Parametric studies & Impedance measurement techniques
Different scales
To the application for complex geometries
Implementation in lower accurate solver
Impedance boundary condition in Convected Helmholtz solver

7. Accurate simulation of flow/sound interaction for perforate structures
To model the acoustic propagation in presence of a mean flow, using a general operator (LEE/LNSE).
Continuous high-order Finite Element method (pFEM) code
Frequency domain,
2D Linearized Navier-Stokes Eq. (can be reduced to LEE)
Matlab® prototype code,
Higher-order Lobatto polynomial shape functions.

8. Numerical hybrid methodology
Y-velocity field for base flow
CFD
CFD mesh
Choice of models
RANS computation
Export base flow
LNSE pFEM
Linearized Navier-Stokes Eq. model simulation
Numerical CAA hybrid methodology
Post-processing
Impedance value estimation
In-situ technique
Eduction method
Two-port method
Acoustic energy dissipation and production

9. Research achievements - Study on 2D slit resonator
Dedicated measurement campaign on 2.5D slit resonator, compared to two LNSE numerical tools.
Gain lacking database for quasi 2D rectangular orifices,
Gain experiences in aero-acoustics numerical tools,
Compare different impedance characterization approaches.

10. Research achievements - Study on 2D slit resonator
Figure: CAD model of the test section (left) and pictures of the opened test object (top right) and the test object built into the rig (bottom right).

11. Research achievements - Study on 2D slit resonator
90 mm
Computational Fluid Dynamics extended domain
Acoustic computational domain
Figure: Schematic overview of the geometry under consideration.

12. Research achievements - Study on 2D slit resonator
Cases done:
Continuous pFEM code
Discontinuous Galerkin method code
Experimental campaign
In-situ x /
Lumped model
Eduction method
Table: Summary of cases investigated.
For Mach numbers M = 0, 0.025, 0.05, 0.075, 0.1.
Over the frequency range [200 Hz – 2000 Hz].

13. Research achievements - Study on 2D slit resonator
Figure: Absolute value of the scatter matrix coefficients for different mean flow Mach numbers.

14. Research achievements - Study on 2D slit resonator
Figure: Normalized resistance (top) and reactance (bottom) for different grazing flow velocities.

15. Future plans
Work on impedance boundary conditions (for convected Helmholtz equation type solver)
Application case to a global system
Further development on the Linearized Navier-Stokes Eq. solver

16. Technical trainings, lectures and workshop
Training / Workshop description
Date
Place
VKI lecture series “Accurate and efficient aero-acoustic prediction approaches for airframe noise
March 2013
VKI, Brussels - Belgium
VKI lecture series “Modelling, measurement and control of ventilation and cooling noise”
April 2013
Non normal and nonlinear effects workshop
June 2013
TUM, Munich -Germany
ISAAC course
September 2013
KUL, Leuven - Belgium
Experimental methods in thermo-acoustics
April 2014
KTH, Stockholm - Sweden
Aero-acoustics in confined flows of low Mach number
IITM, Chennai - India
Experimental NVH training
June 2014
LMS, Leuven - Belgium
Analytical methods in thermo-acoustics
September 2014
Keele University, UK
* Done in the frame of TANGO

17. Complementary skills (research management and communication)
Training /workshop description
Date
Place
Presentation skills
March 2013
LMS, Leuven - Belgium
Outreach Training (1)
September 2013
Deutsches Museum, Munich -Germany
Effective communication training
January 2014
Gender Issue workshop
April 2014
KTH, Stockholm -Sweden
* Done in the frame of TANGO

18. Training /workshop description
Conferences
Training /workshop description
Date
Place
20st AIAA/CEAS Aeroacoustics Conference
June 2013
Berlin, Germany
21st AIAA/CEAS Aeroacoustics Conference
June
Atlanta, USA
“Combined Numerical and Experimental Study of a Slit Resonator Under Grazing Flow”
* Done in the frame of TANGO

19. Networking opportunities
Inside the project
Part of the vibro-acoustic research group at KUL
Secondment to be defined
Extra networks
Member of Belgian Acoustical Society (ABAV) and of B-YAN (Belgian Young Acousticians Network)
Member of Marie Curie Alumni Association (MCAA)

20. Thank you for your attention.
Contact: Jonathan Tournadre