 | Neifeld A. Efficient hybrid CAA method for jet noise prediction of isolated nozzles: Diss. ... Dr.-Ing. / Deutsches Zentrum für Luft- und Raumfahrt, Institut für Aerodynamik und Strömungstechnik, Braunschweig. - Köln: DLR, 2016. - xviii, 95, xxxv p.: ill. - (Forschungsbericht; 2016-65). - Res. also Germ. - Bibliogr.: p.xxvii-xxxv. - ISSN 1434-8454
Шифр: (Pr 1120/2016-65) 02
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Nomenclature ................................................... XV
1 Introduction ............................................... 1
1.1 Preface .................................................... 1
1.2 Latest Progress in Jet Noise Simulation Methods ............ 5
2 Numerical Methods .......................................... 9
2.1 Governing Equations ....................................... 12
2.1.1 Derivation of Azimuthal-Modal Governing Equations .. 12
2.1.2 PIANO and (F)RPM Code Description .................. 15
2.2 Acoustic Source Modeling ................................. 18
2.2.1 Cold Jet Noise Source Model of Tarn & Auriault ..... 19
2.2.2 Extension of RPM with Hot Jet Noise Source Model ... 26
2.2.3 Large-Scale Noise Mechanism ....................... 32
2.3 Ffowcs-Williams & Hawkings Extrapolation for Modal CAA
Computations .............................................. 34
3 Verification .............................................. 37
3.1 Verification of Source Generation ......................... 37
3.1.1 General RPM Verification ........................... 37
3.1.2 Tarn & Auriault Model for Cold Jets ................ 38
3.1.3 Tarn, Pastouchenko & Viswanathan Model for Hot
Jets ............................................... 43
3.2 Verification of implemented Governing Equations ........... 48
3.2.1 Duct Modes ......................................... 48
3.2.2 Influence of Azimuthal Mean-Flow Refraction ........ 51
3.3 Verification of Modal Ffowcs-Williams & Hawkings Method ... 52
4 Validation of Overall Jet Noise Prediction Method ......... 55
4.1 General Remarks on Single Stream Jet Noise ................ 55
4.2 CFD Computations .......................................... 58
4.3 Computational CAA Setup ................................... 62
4.4 Cold Fine-Scale Jet Noise ................................. 64
4.4.1 Near-field Computations ............................ 64
4.4.2 Far-field Computations ............................. 67
4.5 Hot Fine-Scale Jet Noise .................................. 70
4.6 Large-Scale Jet Noise ..................................... 73
4.7 Discussion ................................................ 78
5 Application on Complex Nozzle Geometry .................... 79
5.1 CFD Computations .......................................... 79
5.2 Computational CAA Setup ................................... 81
5.3 CAA Results ............................................... 84
5.4 Discussion ................................................ 87
6 Summary, Conclusions and Outlook .......................... 89
6.1 Summary .................................................. 89
6.2 Conclusions ............................................... 90
6.3 Outlook ................................................... 91
Appendix I
A Derivation of Azimuthal-Modal Governing Equations .......... I
B Forced Azimuthal Duct Modes ................................ V
B.1 Determination of Duct Modes ................................ V
B.2 Derivation of Forced Equations ............................ VI
Figures ........................................................ IX
C Azimuthal-Modal RPM Sources ................................. IX
D Azimuthal Duct Modes ........................................ XI
E Cold and Hot Single Stream Jet Noise Computations ......... XIII
F Azimuthal-Modal Computations of Dual-Stream Jet ........... XVII
G Modal Ffowcs-Williams & Hawkings Surfaces ................. XXIV
Bibliography ................................................. XXIV
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