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1 Free Field Technologies Presentation and General Products Overview Copyright Free Field Technologies

2 Free Field Technologies Free Field Technologies is the technical leader in acoustic, vibro-acoustic and aero-acoustic CAE The company has three main activities: Development of the Actran software suite Provision of related services: training, consulting, technology transfer, methodology development, installation and performance tuning, custom developments, CAE process automation Research in acoustic CAE and related fields Free Field Technologies operates from its headquarters in Mont-Saint-Guibert (near Brussels), Belgium, and from its offices in Toulouse, France, Tokyo, Japan, and Troy, MI, USA. Actran is used by over 200 industrial customers worldwide. FFT joined MSC Software Corporation in September 2011 and became a wholly owned subsidiary of MSC. 2 Copyright Free Field Technologies

Motivation for Acoustic Simulations Engineering

propagation into far field Generic sources Vibrating

reduction Absorption (porous media) Sound

Transmission loss Transfer functions Damping of

3 Motivation for Acoustic Simulations Engineering tasks for acoustic simulation Sound radiation and propagation into far field Generic sources Vibrating structures Turbulent (unsteady) fluid flow Noise reduction Absorption (porous media) Sound transmission & fluid-structure interaction Transmission loss Transfer functions Damping of vibration by heavy fluids Sender room Receive r room 3 Copyright Free Field Technologies

4 Motivation for Acoustic Simulations Disciplines of acoustics simulation Sound radiation and propagation into far field Generic sources Vibrating structures Acoustics (propagation & weak coupling) Turbulent (unsteady) fluid flow Aero-Acoustics Noise reduction Absorption (porous media) Sound transmission & fluid-structure interaction Transmission loss Transfer functions Damping of vibration by heavy fluids Vibro-Acoustics 4 Copyright Free Field Technologies

5 Actran VI The Actran software suite Actran for NASTRAN Actran DGM Actran Vibro-Acoustics Actran Aero-Acoustics Actran TM Actran Acoustics 5 Copyright Free Field Technologies

Actran Acoustics General purpose acoustic modelling tool

$diffraction by rigid obstacles Sound radiation by vibrating$ Actran VibroAcoustics Actran AeroAcoustics Actran TM Exhaust

6 Actran Acoustics General purpose acoustic modelling tool Target applications: Sound propagation in ducts Sound diffraction by rigid obstacles Sound radiation by vibrating structures Pre-requisite for more advanced Actran modules: Actran VibroAcoustics Actran AeroAcoustics Actran TM Exhaust Muffler HVAC Module Gearbox Radiation 6 Copyright Free Field Technologies

Actran VibroAcoustics General purpose vibro-acoustic modelling tool Large finite element and material library: acoustic finite and infinite elements incl.

finite elements Piezo-electric elements for modelling active structures Realistic excitation mechanisms: acoustical, kinematical and dynamical excitations

7 Actran VibroAcoustics General purpose vibro-acoustic modelling tool Large finite element and material library: acoustic finite and infinite elements incl. pyras and pentas visco-elastic elements for beams, shells and solids Composite elements allowing also the handling pre-stress effects Porous and poro-elastic finite elements Piezo-electric elements for modelling active structures Realistic excitation mechanisms: acoustical, kinematical and dynamical excitations turbulent boundary layer diffuse sound field High-performance solvers and parallel processing Loudspeaker Side window transmission Muffler Radiation 7 Copyright Free Field Technologies

Actran for NASTRAN From body-in-white to

8 Actran for NASTRAN From body-in-white to trimmed body vehicle models (fully compatible with Nastran) A technology providing the right blend of accuracy and speed In phase with the distributed development process References: Ford, Nissan, MMC, GM, Rieter,... Trim is everywhere Superlement coupling From BIW to trimmed body 8 Copyright Free Field Technologies

Actran AeroAcoustics Broadband aero-acoustics

Direct link to most CFD codes Validated by

9 Actran AeroAcoustics Broadband aero-acoustics modelling tool (vortex noise) Key features: Direct link to most CFD codes Validated by experiments for fans, side window noise and simplified Air Conditioning systems References: Daimler, BMW, VW, Delphi, Visteon, John Deere, Brothers, PSA... Fan noise Air conditioning duct Correlation to test 9 Copyright Free Field Technologies

10 Actran TM Exclusive tool for the modelling of noise radiation by aircraft engine and other turbomachines Key features: excitation defined in terms of duct modes propagation in a non-uniform background flow accurate modelling of liners References: Airbus, Rolls-Royce, SNECMA, General Electric, MTU, Honeywell, Liebherr, Turbomeca, Aermacchi,... Aermacchi Airbus Airbus 10 Copyright Free Field Technologies

Actran/DGM Objective: solve exhaust turbine

RANS-based mean flow from most standard CFD

11 Actran/DGM Objective: solve exhaust turbine noise Key features: Linearized Euler Equations (LEE) DGM scheme in the time domain Non-structured mesh Import the RANS-based mean flow from most standard CFD codes Each best element chooses its best order (1 to 16) Complex Exhaust Flow Acoustic field TURNEX Project 11 Copyright Free Field Technologies

recovered from other CAE tools Advanced results display capabilities Model creation

12 Actran VI Actran s own pre- and post-processor Validation and modification of Actran models created with other tools Creation of Actran model directly form mesh data recovered from other CAE tools Advanced results display capabilities Model creation and validation Advanced post-processing FRF Display Tool 12 Copyright Free Field Technologies

13 Some of our Automotive Customers 13 Copyright Free Field Technologies

14 Some of our Aerospace Customers 14 Copyright Free Field Technologies

15 Some Other References 15 Copyright Free Field Technologies

16 压缩机声学 Copyright Free Field Technologies

17 Reduction of Discharge Gas Pulsation of HVAC Compressor by using Numerical Acoustic Solver ACTRAN Pierre POYSAT EMERSON Climate Technologies Copyright Free Field Technologies

18 HVAC System: Description Copyright Free Field Technologies

HVAC System: Description NVH Challenges for compressor manufacturer Reduce compressor noise Structure borne Airborne Reduce the disturbing energy from the compressor to the system Rigid body

19 HVAC System: Description NVH Challenges for compressor manufacturer Reduce compressor noise Structure borne Airborne Reduce the disturbing energy from the compressor to the system Rigid body vibration Discharge gas pulsation Heat exchanger noise radiation Minimize risk of piping failure System reliability (fresh good conservation) Environment Copyright Free Field Technologies

20 Dual Scroll: Compressor Description Suction Gas Discharge Gas 50% Flow through 4 Slots 50% Flow 20 Copyright Free Field Technologies

21 Discharge gas pulsation: how to control? Destructive interference Efficient to control discharge pulsation when compressor operating at 100% Pulsation still too high at the check valves Impact on Reliability Alternative solution Discharge volume increase Original: 0.4 L Quick fix: complex, large volume 4.4L Objective: Reduce the volume from quick fix Constrains Size (cost, manufacturing) Weight Pulsation attenuation HW limitations Inside Pressure Copyright Free Field Technologies

22 Experimental setup & Model Frequency range: Hz m1, m2, m3, m4, m5: m5 m4 m3 pressure transducers m2 m1 22 Copyright Free Field Technologies

23 Geometries Simulations done for 6 designs variable speed of sound Not tested Volume 4.4 Volume 1.76 (FFT) Volume 1.76 (Cop.) Volume 1.36 Volume 0.96 Volume Copyright Free Field Technologies

24 Results Pressure map 100 Hz modèle Copeland modèle FFT 24 Copyright Free Field Technologies

25 Results Pressure map 300 Hz modèle Copeland modèle FFT 25 Copyright Free Field Technologies

26 Conclusion of the study Damping volume can be reduced to 1.4 L Shape has a limited impact since major contribution to discharge pulse is 100 Hz component Freedom for design Strong positive impact on cost, weight, dimension, resistance to high pressure 26 Copyright Free Field Technologies

27 Actran 汽车行业应用 Copyright Free Field Technologies

28 结构振动噪声辐射 Copyright Free Field Technologies

29 Case Study : Acoustic Radiation of Large Powertrain Reference : Experimental Validation of an Efficient Procedure for Large Acoustic Radiation Problems, M.Gustafsson, J.Jacqmot, S.Caro - ISMA 2010 conference Copyright Free Field Technologies

30 Introduction This project: a complete truck powertrain, length around 2.5 meters The structure vibration levels are computed with an external FEA solver The results (velocities or displacements) are used as the excitation of the acoustic radiation problem solved by Actran Several RPM s of the power train are considered The numerical results are compared with measurement performed by Volvo 30 Copyright Free Field Technologies

31 The reference engine 13 litre 6 cylinder in-line engine with manual gearbox Noise measurement with a 28 microphone array 31 Copyright Free Field Technologies

32 Computation Process In the following, we only focus on the acoustic computations 1. Vibration modes and participation factors Binary files 2. Acoustic computations (Actran) 3. Post Processing and Analysis Maps FRF Waterfall 32 Copyright Free Field Technologies

33 Modeling Steps Acoustic Model 1. Structural FEA model 2. Create finite element mesh 4. Post-process in Actran 3. Create Actran model in Actran COMPUTATION 33 Copyright Free Field Technologies

34 Model Specifications Mapping the vibration levels The vibration levels are projected on a specific surface (named "BC mesh") This BC mesh is the source in the Actran model Propagation Near field: 4 linear finite Elements per wavelength (low dispersion elements developed by FFT) Far field: the Infinite Elements model the free field condition and give results anywhere in the far field Note: the infinite elements must not be meshed (boundary condition) Infinite Element Surface 3D elements (TET + PYRA + HEXA ) BC_MESH Surface 34 Copyright Free Field Technologies

for vibration excitation boundary condition. 2.

for far-field boundary condition including the

Generate the acoustic 3D mesh in between. 4.

35 Acoustic Model Preparation 1. Generate a closed surface wrap of the engine for vibration excitation boundary condition. 2. Generate a convex offset of the engine surface for far-field boundary condition including the reflecting floor. 3. Generate the acoustic 3D mesh in between. 4. Import microphone coordinates 5. Link the engine surface patches to corresponding results files (real valued modes shapes and modal coordinate files) 35 Copyright Free Field Technologies

frequencies on the acoustic mesh or/and on a mesh dedicated to the post-processing (named field mesh in Actran)

36 Results Output Specification Virtual microphones can be located anywhere in the finite and/or infinite element domain Output specifications Multiple control surfaces to compute the radiated power Maps for different frequencies on the acoustic mesh or/and on a mesh dedicated to the post-processing (named field mesh in Actran) Plot acoustic pressure, acoustic intensity, etc. field points (microphones) field mesh 36 Copyright Free Field Technologies

37 Results - SPL Comparisons 3 db 37 Copyright Free Field Technologies

38 Panel Contribution 38 Copyright Free Field Technologies

39 Maps of the acoustic fields 500 Hz 1500 Hz 39 Copyright Free Field Technologies

40 Study of the Noise radiated by an Intake Manifold Hiroyuki Abe MAZDA Work presented at the Actran 2011 User s Meeting in Japan Copyright Free Field Technologies

Introduction Mazda has developed a new engine in order to reduce the fuel consumption as well as the weight (among others) To achieve this, Mazda decided to use a thin resin intake manifold

41 Introduction Mazda has developed a new engine in order to reduce the fuel consumption as well as the weight (among others) To achieve this, Mazda decided to use a thin resin intake manifold Consequence: many modes are present because of the low rigidity of the intake manifold and therefore some significant noise problem occur Mazda had to consider many structural modifications in order to fix this problem 41 Copyright Free Field Technologies

42 Computational Process Intake Vibrations PT Vibration - NASTRAN Acoustic 42 Copyright Free Field Technologies 42 Evaluation Point

43 Results Rigid Parts except Intake Test-CAE Original 4000rpm Correlations are very good! TTest e CCAE A E 43 Copyright Free Field Technologies

44 Comparison with Experiment Waterfall Diagram 一目盛り 5dBA 一目盛り 5dBA 一目盛り 5dBA 一目盛り 5dBA Mic1 Mic2 Test CAE Correlations are very good! 44 Copyright Free Field Technologies

315 400 500 630 800 1000 1250 1600 2000 2500 S.P.L.

45 S.P.L. (dba) 一目盛り 5dBA Design Improvement Thanks to the accuracy and to the performance of Actran, Mazda can use the numerical simulation to improve the acoustic performance of its engines Point1 SPL 2000rpm BASE MODIFY Element Contribution 1/3Oct. Band (Hz) The weight has been reduced as well as the noise (4dB at the maximum) 45 Copyright Free Field Technologies

46 内饰部件声学性能分析 Copyright Free Field Technologies

47 车身内部内饰材料 47 Copyright Free Field Technologies

实验装置 Vibro-acoustic FEA Modeling of Two Layer

Glandier and Ralf Lehmann(DaimlerChrysler AG),

Kamada(Mitsubishi Motors Corporation),SAE 2005

48 实验装置 Vibro-acoustic FEA Modeling of Two Layer Trim Systems, Christian Y. Glandier and Ralf Lehmann(DaimlerChrysler AG), Takashi Yamamoto and Yoshinobu Kamada(Mitsubishi Motors Corporation),SAE 2005 研究对象 : 弹性板 + 多孔泡沫材料 + 厚板 Excitation system 激励方式 : 激振器作用于连接内饰部件的框架两种外部空间工况自由场声辐射在封闭箱体内的辐射 Free field radiation / closed box radiation 48 Copyright Free Field Technologies

49 计算模型建立的网格模型包含每一层的内饰部件框架以及空气域计算两种内饰部件, 材料属性如下表所示 : 49 Copyright Free Field Technologies

50 计算结果结构响应弹性板中心加速度响应 ( 纤维材料 ) 厚板的平均速度响应 ( 纤维材料 ) 50 Copyright Free Field Technologies

51 计算结果声学响应距厚板 1 米处声压级 ( 泡沫材料 ) 距厚板 1 米处声压级 ( 纤维材料 ) 51 Copyright Free Field Technologies

52 空调通风口声学分析 Copyright Free Field Technologies

53 空调系统的噪声问题空调系统的作用舒适性 ( 制热, 制冷, 通风 ) 安全性 ( 除雾 ) 仪表板通风管道的质量标准压力损失气流指向性, 流动是否均匀声学性能 ( 气动噪声 ) 53 Copyright Free Field Technologies

54 格栅对气动噪声影响分析 54 Copyright Free Field Technologies

55 格栅对气动噪声影响分析 55 Copyright Free Field Technologies

56 Central Duct Experimental Set-Up ACTRAN Results CFD Results - Fluent 56 Copyright Free Field Technologies

57 进排气系统声学分析 Copyright Free Field Technologies

58 进排气系统模拟利用 ACTRAN 可以方便地模拟进气和排气系统排气管噪声管道内声音传播反射评估出口的辐射阻抗壳体辐射噪声采用传递矩阵法模拟管道系统声学特性计算模型可以考虑的因素 : 流固耦合开放的出口端消声器绝热层吸声材料穿孔板流动效应温度效应 In Out (shell) Out (pipe) 58 Copyright Free Field Technologies

59 排气管噪声问题描述排气系统一个部件的噪声 ( 例如 : 消声器 ) Incident power from the engine Transmitted power (pipe noise) Not reflective BC 计算传递损失 (TL) TL =10*log10(W incident /W transmitted ) 结合传递矩阵法, 计算排气系统整体的降噪效果 59 Copyright Free Field Technologies

60 温度效应 Transmission Loss With temperature 600K 300K 60 Copyright Free Field Technologies

Acoustic elements, exhaust interior Shell elements, exhaust skin Actran

61 整体声学模型 Outlet exhaust noise + shell radiated noise in one unique model Acoustic FEM/IEM interface fluid 2 (ρ 2,c 2,T 2 ) fluid 1 (ρ 1,c 1,T 1 ) Acoustic elements, exhaust interior Shell elements, exhaust skin Actran 支持不匹配网格 61 Copyright Free Field Technologies Acoustic elements, outside fluid

62 整体声学模型计算结果 Energies spectra Exterior sound field Interior cavity SPL Structure deformation 62 Copyright Free Field Technologies

63 ACTRAN 的传递矩阵方法 (TMM) 解析的传递矩阵方法功能有限只适用于简单形状仅限于平面波 (see ) 不能模拟壳体辐射噪声均匀介质对于更复杂的模型, 可以结合 ACTRAN 使用传递矩阵方法复杂几何更高的频率范围壳体辐射噪声 + 结构耗散流动和温度梯度 TMM analytic codes are limited to the lowest cut-on frequency of all the elements (inlet/outlet/internal duct). Ex: Ex: F inlet = 8000Hz F internal = 2000Hz F outlet 6000Hz TMM analytic codes can perform the TL computation only until 2000Hz. Mix-method (ACTRAN+TMM) can compute the TL until the lowest cut on frequency of the inlet/outlet duct. F inlet = 8000Hz F internal = 2000Hz In this case, ACTRAN can perform the TL computation until 6000Hz 63 Copyright Free Field Technologies

into subsystems Task 3: Results recombination using TMM To be performed

64 64 Copyright Free Field Technologies TMM 分析整体排气系统的优势 Task 2a: ACTRAN Model creation Task 2b: ACTRAN computations Task 1: Geometry Division into subsystems Task 3: Results recombination using TMM To be performed for each component * P R I R I R T = T1*T2*T3

65 整车声学分析 Exhaust Noise Transmission to the Interior of a Trimmed Vehicle Reference : Numerical Prediction of the Exhaust Noise Transmission to the Interior of a Trimmed Vehicle by using the Finite/Infinite Element Method Diego d Udekem et al. (FFT), Takashi Yamamoto (Nissan Motor Co Ltd), SAE International 2011 Noise and Vibration Conference and Exhibition, 2011, Michigan, USA Copyright Free Field Technologies

the distributed pressure on the exterior of the car structure, get the pressure fluctuations in the car cavity

66 From Exhaust Noise to Trimmed Body Two-step approach: Exterior Acoustic Model Interior Vibro-Acoustic model From the plane wave source in the exhaust pipe, get the distributed pressure on the exterior of the car structure From the distributed pressure on the exterior of the car structure, get the pressure fluctuations in the car cavity (modal approach with trims) ACTRAN Acoustic FE/IE model ACTRAN for Nastran model 66 Copyright Free Field Technologies

67 Validation - Exterior Acoustic Analysis The distributed pressure on the exterior of the car structure is compared with experimental data : Experimental setup : Spherical source set at the exhaust, Measure on right side of vehicle with 100 mm resolution Measurement Calculation 5 Measurement Calculation 6 100Hz 300Hz Measurement Measurement Calculation 67 Copyright Free Field Technologies Calculation

68 Dash insulator and floor carpet Experiment Simulation Dash insulator and floor carpet W/o insulator W/ insulator W/o insulator W/ insulator Acoustic transfer function Acoustic transfer function Structure transfer function Structure transfer function 68 Copyright Free Field Technologies

69 Sound Pressure Response in Cabin The Transfer function from speaker source to ears position is displayed with and without insulator 69 Copyright Free Field Technologies

70 风噪声模拟 Copyright Free Field Technologies

71 风噪声模拟主要因素物理模型结构流体与结构耦合车身内饰材料风挡多层结构材料属性 (Frequency dependent) 声学激励点力载荷扩散声场湍流边界层 (Turbulent boundary layer) 空气动力性载荷 windshield PVB Glass 71 Copyright Free Field Technologies

72 载荷方式 1- 点力载荷 1000 Windshield Modal analysis, free-free BC simulation experimental 100 Acceleration [m/s2] Frequency [Hz] 72 Copyright Free Field Technologies

Transmission Loss (db) 1200 1000 800 600 400 200 0 载荷方式 2-

AN/mesures BMW S 閞 ie 3 ESSAI 1 ESSAI 2 ACT RAN 40 35 30 25 20

73 Transmission Loss (db) 载荷方式 2- 扩散声场激励 T ransparence acoustique - Comparaison simulations ACT R AN/mesures BMW S 閞 ie 3 ESSAI 1 ESSAI 2 ACT RAN Fr 閝 uence [ Hz] 73 Copyright Free Field Technologies

74 载荷方式 3- 湍流边界层激励 Model Description Mode 2-73Hz (A) - 185Hz (S) Glass + Seal detail Mode Hz (A) - 612Hz (S) 74 Copyright Free Field Technologies

75 载荷方式 4- 空气动力性载荷 OpenFOAM CFD computation Unsteady incompressible CFD (pressure, velocity) Actran/VI Pre-processing Mesh generation Actran file setup Actran/ICFD Interpolation of the turbulence pressure fluctuations on the acoustic mesh Actran/ICFD Fourier Transform TWPF into the frequency domain Actran VibroAcoustics Acoustic computation Use of the TWPF excitation into Actran Actran/VI Post-processing Color map, pressure plot Copyright Free Field Technologies

CFD pressure fluctuations TWPF excitation Sound pressure

76 Sound pressure Level [db] ACTRAN Aero/Vibro-Acoustic 耦合计算结果 Color Map of Pressure, Deformation of the side window 750Hz CFD pressure fluctuations TWPF excitation Sound pressure level at drivers ear 10dB 76 Copyright Free Field Technologies

77 Simplified Train Compartment Vibro-Acoustic Demonstration Model geometry provided by CSR Zhuzhou Electric Locomotive, China Copyright Free Field Technologies

78 Introduction Vibro-acoustic modeling of a simplified train compartment Length: 4 m Height: 3.12 m Width: 3 m Three layer structure: 10 mm of aluminum, 10 mm of porous material, 10 mm of plastic Window: glass Door: Iron Excitation: point forces from the suspension (on the floor structure) Frequency range: 5 Hz 500 Hz, with a step of 5 Hz Symmetric modeling using half geometry Two steps modeling: 1, coupled structure and inner cavity ; 2, acoustic radiation into semi free field (taking the ground reflection into account) 78 Copyright Free Field Technologies

79 Model Presentation - 1 Three layer structure: Outer layer: aluminum, 10 mm Middle layer: porous material, 10 mm Inner layer: plastic material, 10 mm Window: one layer: glass material, 30 mm Door: one layer: iron material, 30 mm Inner cavity: Standard air 79 Copyright Free Field Technologies

Model Presentation - 2 Two loading positions: 1, Point load of 1N on the floor under the window 2, Point load of 1N on the floor under the door, with opposite phase than the first point load Three

80 Model Presentation - 2 Two loading positions: 1, Point load of 1N on the floor under the window 2, Point load of 1N on the floor under the door, with opposite phase than the first point load Three loadcases: 1, Only point load 1 is applied on the model 2, Only point load 2 is applied on the model 3, Combination of the load 1 and load 2 with equal contribution factor is applied on the model Boundary condition: 80 Copyright Free Field Technologies 1, On the connection with compartment extension, structure displacement along the train length set free, other two components set to zero 2, On the symmetry plane, structure displacement component normal to the symmetry plane set to zero, other two components set free

81 Modeling step 1 Structure and inner cavity Transfer function (db) Transfer function (db) Results under loadcase Hz, directivity, (db) point load of 1N on the floor under the window Transfer function: Sound pressure level / point load Microphone 1, frequency response function, (db) Copyright Free Field Technologies

load of 1N on the floor under the window 10 500

82 Modeling step 1 Structure and inner cavity Results under loadcase Hz, SPL (db) point load of 1N on the floor under the window Hz, SPL (db) Copyright Free Field Technologies

compartment Origin of infinite domain placed on the floor, taking account of exterior ground reflection Vibration of structure

83 Modeling step 2 Acoustic radiation Model: acoustic radiation from the vibration of structure skin calculated in step 1 Finite element for near field acoustic Outer air domain length extended, taking account of the scattering effect of neighboring compartment Origin of infinite domain placed on the floor, taking account of exterior ground reflection Vibration of structure as boundary condition Infinite element for far field radiation Rigid wall (default) boundary condition 83 Copyright Free Field Technologies

84 Transfer function (db) Modeling step 2 Acoustic radiation Transfer function (db) Transfer function (db) Results under loadcase 1: point load of 1N on the floor under the window 100 Hz, inner arc directivity, (db) 500 Hz, inner arc directivity, (db) 500 Hz, outer arc directivity, (db) Two series of far field microphones Copyright Free Field Technologies

85 Modeling step 2 Acoustic radiation Results under loadcase 1: point load of 1N on the floor under the window 200 Hz, SPL (db) 200 Hz, SPL (db) 500 Hz, SPL (db) 500 Hz, SPL (db) 500 Hz, SPL (db) 85 Copyright Free Field Technologies

86 ACTRAN VibroAcoustics for Aircraft ACTRAN Features for Cabin and Cockpit Noise Copyright Free Field Technologies

87 Aircraft Noise Major Contributors Interior Noise Overall Interior noise level External noise sources Internal noise sources Engine Boundary Layer ECS Environment Control System Avionics System Other systems (hydraulic, electrical systems, etc) Air borne Structure borne Windows Structure Radiated Noise Engine noise during landing and take-off phases APU noise while engines off 87 Copyright Free Field Technologies

88 Efficiency of Fuselage Panels Unique features to model all the mechanisms of damping, absorption & transmission in multi-layered trim panels : Viscoelastic, porous materials (Biot model) & stiffeners Fluid-structure coupling (one model inculding the structure and the acoustic) Fast FRF Krylov solver stiffeners aluminum layer 1 layer 2 air layer 3 88 Copyright Free Field Technologies

Noise Transmission through Fuselage & Cockpit Models

structural heterogeneity effect Variable thickness

Frames & stringers Floor Added masses Excitation

(Corcos) Engine structure borne vibrations User

89 Noise Transmission through Fuselage & Cockpit Models FEM Actran models take into account: Real shape & structural heterogeneity effect Variable thickness skin Multi-layered windows Glass wool (Biot model) Frames & stringers Floor Added masses Excitation type effect Diffuse field Turbulent boundary layer (Corcos) Engine structure borne vibrations User defined (e.g. propeller noise) 89 Copyright Free Field Technologies

90 Noise Transmission through Fuselage & Cockpit Typical results NR(dB) Cockpit sound transmission Cockpit sound transmission 10 db Cabin structure response F(Hz) 90 Copyright Free Field Technologies

Composite or Aluminum Fuselage Stringers and Frames Example with Actran 11 (year 2010) 2.

91 A more Realistic Model Objective: Compute the interior noise induced by a Diffuse Sound Field excitation Modeling : Half Model (symmetry BC), Upper cavity (5 m3) Insulation (Glasswool) Multi-layered windows Composite or Aluminum Fuselage Stringers and Frames Example with Actran 11 (year 2010) 2.1 MDOFs model, valid up to 5kHz Runs in 2.2 hours on 2x4 threads with 2x30GB RAM 91 Copyright Free Field Technologies Courtesy of Airbus

92 Going Further Advanced features Copyright Free Field Technologies

93 Composite Materials in Actran A composite material is an assembly of 2 or more materials, put together to obtain performances higher than any of it s constituents The composite shell is usually multilayered with plies having a specific fiber direction 2 E l =135E9 Pa E 1 t =8.5E9 Pa nu 12 =0.35 nu 23 =0.00 The fiber direction vary from one ply to another G 12 =4.2E9 This gives specific mechanical properties (fatigue, weight) 93 Copyright Free Field Technologies

Pressurization in Actran Computations for assessing the effect of the pressurization p i p o Average flight configuration : p i - p o = 50kPa The pressurization is a static load modify the dynamic

94 Pressurization in Actran Computations for assessing the effect of the pressurization p i p o Average flight configuration : p i - p o = 50kPa The pressurization is a static load modify the dynamic stiffness of the entire system In practice in ACTRAN: work in two steps: Step 1: Computation of the static response determination of the INITIAL_DISPLACEMENT Step 2: Computation of the dynamic response using the results of step 1. The software uses the updated system stiffness Use: airplane applications, underwater applications 94 Copyright Free Field Technologies

95 ACTRAN / TM A unique environment for modeling turbo-machinery noise Copyright Free Field Technologies

96 Aircraft noise sources Source: ICCAIA, moteur PW Copyright Free Field Technologies

ACTRAN/TM Key features Handle the effect of backgound flow Models both near field and far field (important for certification) Includes an accurate model of

97 ACTRAN/TM Key features Handle the effect of backgound flow Models both near field and far field (important for certification) Includes an accurate model of the fan source Optimized for large models (high frequency) Including the very complex exhaust flow Accounts for all liners 97 Copyright Free Field Technologies

Tonal Source Modeling Duct Modes The source

(Tyler&Sofrin theory) In practice: set of

azimuthal order Well established rules help

1 Azimuthal order =0 Radial order = 1 Radial

98 Tonal Source Modeling Duct Modes The source is represented by series of duct modes (Tyler&Sofrin theory) In practice: set of rotating modes with a given radial and azimuthal order Well established rules help choosing the modes amplitudes and phase at BPFH and at any other frequency The reflected modes are let free (non reflecting boundary condition) All types of duct section are handled by ACTRAN Radial order = 1 Azimuthal order =0 Radial order = 1 Radial order = 2 Radial order = 3 Azimuthal order = 4 Azimuthal order =4 Azimuthal order =4 Axisymmetric Nacelle & Splitter in a Bypass 98 Copyright Free Field Technologies

domain Muffler Directivity Diagram Nacelle radiation, flow, no liner - 500Hz,

99 Far Field: Acoustic Infinite Elements Two roles: Act as a non reflective boundary condition (Free field modeling) Give access to results outside the computational domain Muffler Directivity Diagram Nacelle radiation, flow, no liner - 500Hz, mode (3,0) Copyright Free Field Technologies

Admittance Influence With Liner and flow

100 Liners: Admittance Boundary Conditions ACTRAN TM models with accuracy the liners including the effect of the grazing flow (as per the Myers-Eversman formulation) Admittance Influence With Liner and flow Without Liner, with flow 100 Copyright Free Field Technologies

indicators allow performing the energy balance of the system All of

101 Output ACTRAN can output maps in the near and far fields Directivity diagrams can also be output thanks to virtual microphones Energy indicators allow performing the energy balance of the system All of these output allow performing accurate design study 101 Copyright Free Field Technologies

Caruelle See also validation on JT15D : Development and validation of a parallel out-ofcore

102 Experimental Validation ICSV 2005 Fan Noise Radiation from Intake: Comparisons Between FEM Prediction and Fan Rig Test Measurements with Flare S.Lidoine & B.Caruelle See also validation on JT15D : Development and validation of a parallel out-ofcore propagation and radiation code with validation on a turbofan application, P.Ploumhans et al, ICA Copyright Free Field Technologies

103 Actran 高性能计算, 并行计算 Copyright Free Field Technologies

104 高性能计算 CPU (ex.: 2 way, 2 core) 内存 (ex.: 32GB) 使用并行计算,MPI (Message Passing Interface) 使用高性能 BLAS (Basic Linear Algebra Subprograms) Extra-node, 使用高性能 Switch (Myrinet, InfiniBand, etc.) 104 Copyright Free Field Technologies

105 并行计算方式频率并行计算域并行计算矩阵 ( 有限元矩阵 ) 并行多线程 (thread) 计算 105 Copyright Free Field Technologies

sequential/parallel time parallel/sequential RAM ACTRAN TM Performance on a real intake AIAA2006-2588: New advances in the use of ACTRAN TM for nacelle simulations and optimization of IBM clusters

106 sequential/parallel time parallel/sequential RAM ACTRAN TM Performance on a real intake AIAA : New advances in the use of ACTRAN TM for nacelle simulations and optimization of IBM clusters for ACTRAN parallel computations, A.Mosson, S. Caro, T.Knapen, M.Gontier, L.Enault, S.Drouilhet-Peyre Performance tests have been performed with Airbus to optimize the parallel scalability Running in parallel lowers the RAM needs (and the computational time) axis symetric run - parallel version efficiency axis symetric run - RAM consumption linear behaviour 59kdofs 225kdofs 871kdofs 1250kdofs linear behaviour 59kdofs 225kdofs 871kdofs 1250kdofs CPU number CPU number 106 Copyright Free Field Technologies

107 典型大型并行计算项目问题规模 : 一千二百万自由度 CPU 数量 :30 内存 :70GB 并行方式 : 计算矩阵并行计算 107 Copyright Free Field Technologies

Free Field Technologies

Free Field Technologies SFA Conference Toulouse the 25 th of November 2010 Copyright Free Field Technologies Free Field Technologies Free Field Technologies is a technical leader in the field of acoustic,