Fred Mendona dona, CD-adapco dapco Cont ntinuing nuing Challen - - PowerPoint PPT Presentation

Cont ntinuing nuing Challen llenge ges s in n Aeroac

• acou
• ustics

stics Simulation mulation

Curre rrent nt Prac actices ices and nd Future ture Prospects rospects STAR AR Korea rea Conf nfere erenc nce e 2012 Aeroacou

• acoust

stics ics and CFD-base sed d wavenumb enumber er analys ysis is towards ds aero-vibr vibroa

• aco

coustics ustics

Fred Mendonça donça, CD-adapco dapco

HVAC, C, ECS, S, Duct t ventilation ilation and disc schar arge ge

Ext xtern ernal al Aeroa

• aco

coust ustic ic Excitation itation

Surface FFT (dB) at 500Hz (top) and 1000Hz (bottom)

Airframe frame and Jet et noise se

Turbo bo compressor ressor Noise se

HVAC C – blower er, , distr tribu ibutor

• r,

, ducts

Pipe e singi ging

Sunroo

• of/side

f/side-windo window w buffeti eting g – real l vehicle le effects ts

Uncorrected Correlated

Alumin iniu ium Persp rspex MDF

– Wall compl mplian ance ce effec ects ts

• Full FSI of comp

mplian ant t wal walls s (below left) t)

• Corre

relati tions ns for wal wall comp mplianc nce e (below right ht)

– Changes es natural l cavity ity freq equen ency – Qualit lity Fac actor

• r causes

ses damping ing

– Leaka kages ges

Hydroac

• acousti
• ustics / cavita

tatio tion n noise se

Aeroa

• aco

coust ustics ics requir iremen ements ts for vibro-ac acoustics?

• ustics?

Ae Aeroacous roacoustics ics Sim Simulations lations Optio ions ns Steady ady stat ate Transient ansient

Broad

• adban

band d Correla rrelatio ions ns Synt nthe hesized ized Fluc uctua uatio ions ns SNGR CURLE

surf

urfac ace PROUDMAN AN

volume

• lume

GOLD LDST STEI EIN 2D-ax axi LEE LEE Lille ley Mesh Freq eque uenc ncy Cut-off LES LES DES Trans ansien ient RANS Point int/Sur Surfac ace e FFTs and d iFFTs Auto

• and

d Cros

• ss Spec

ectra ra – cohe here renc nce e and d phas ase FW FW-H Expor port com

• mmerc

rcial ial prop

• paga

agation ion codes

• des

Expor port to

• Propa
• pagat

gation ion code des Direc ect Noise Prop

• paga

agatio ion 1D (and nd 2D) ) Wavenum enumber ber analy alysis is

Focus s on Transient ansient and Aeroa

• acoustics

coustics

– LES-type turbulence model

• DES (opti

tions

• ns of Spalart-Allmar

maras as, , k-ε, k-ωSST)

• DES advecti

tion n scheme blendi ding ng

• Full LES (wal

wall resolved ed or under er-re resol solved d ! )

– Advanced wall treatment

• y+ inse

nsens nsitive

– Non-reflecting conditions for

• Inflo

low and outfl flow bounda dari ries es

– Full Compressibility

• Intera

eracti ction n bet etween the flow and acoustics stics

– Espec ecia ially lly for cavi vity ty reson sonanc ance e

– Very efficient commercial transient solver

• 2nd

nd order

r space and time discreti scretisati sation

– Spectral Analysis

• FFT and iFFTs at points

nts and surfac aces es

• Auto and Cross

ss spectra ctra – coherence nce and phase se

• Frequ

quency ncy and Wave Number r Fouri rier r analysis sis

FFT post-pr proc

• cess

essin ing g (point)

• int)

– Monitor point in mirror wake – Tail-off in predicted spectrum at mesh cut-off frequency of ~1000 Hz STAR Experiment

Direct ect Propagat pagation ion in STAR-CC CCM+

– Mesh requirement

• 20 cells per acoustic wavelength ( λ= c / f )

– In ambient conditions, you need cells of ~15mm to propagate a signal at 1000Hz – Domain size = 1000D, (~10 λ )

– Non-reflective in/outflow boundaries

– STAR results capture the acoustic sources for propagation via

• Ffowcs Williams-Hawki

wkings ngs (far-field eld pro ropagati tion n of compact sources witho thout t int nternal rnal refl flecti ctions)

• ns)

– STAR offers coupling to 3rd party propagation codes:

• FFT, ACTRAN

AN

• LMS,

, Virtu tual.La al.Lab.A b.Acou

• ustic

tics

• ESI, VA-One

– VibroAcoustics

• Using

ng FVS in STAR-CC CCM+

• Export

t to SEA and FEA

100 0 Hz 500 0 Hz 3150 50 Hz Over erall all

Propagat pagation ion – FW FW-H H and 3rd

rd party

ty code expor

• rt

Introdu

• duction

ction to 1D (line) ine) WaveNumber mber Analysis ysis

Φc(k,ѡ)

ѡ k k0=ѡ/c0 kc=ѡ/Uc

Φ0 (k, ѡ)

Φc(k,ѡ)

ѡ k k0=ѡ/c0 kc=ѡ/Uc

Φ0 (k, ѡ)

Bremne mner and Wilby AIAA-200 2002-255 2551

Wave venumber (rad/m) /m)

Idealised side-view mirror

DAR ARP acousti ustic tun unnel nel open en secti ction

• n

40ms ms-1 open en jet et Mirror

• r height

ight is 15cm cm Re = 2x105 based ed on mirror

• r diame

meter r (half f dimen mensi sion

• ns

s of the e origina inal l Daimle ler r exper perimen iment AI AIAA AA-1999 999-1895 895) 11 million

• n cells

ls Refined wake and “side-glass” 2mm m resolution

• lution

CFD previously viously validat ated ed

– AIAA-2011-2843

South utham ampt pton

• n Uni

Univer ersit ity y Setu etup

1D wave number er analysis lysis on attac ached hed and separat arated ed zones es

a+ a- u- a+ a- u+

2D wave number er analysis lysis at disc scre rete e freque uencies cies

Convectiv ctive e ridge ge Ac Acoustic tic circl cle

Separat arating g the acoustic stic conten ent

Total al and acoust stic ic power input ut to vibrat ration ion analysis ysis

Extens enstion tion to 2D WNA A in STAR-CCM+ v∞ Det etail ailed ed Valid idat ation

• n from Southam

thampton

• n Exper

erim imen ent

– See AIAA Aeroacoustics Conference 2012

Validation idation on produc uction tion Vehicles es CFD gene nera rated d acous

• ustic

tics driving ing

– Propagating acoustics – Diffuse acoustics

in n SEA/ A/FEA FEA vibroac

• acous
• ustic

tics models for interior erior noise transm ansmission. ion. THANK NK YOU for your ur KIND D ATTE TENTI NTION ON

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