TURNEX. Turbomachinery noise radiation through the jet exhaust. January December Partners, 4.7 Million Euro

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1 Turbomachinery noise radiation through the jet exhaust January December Partners, 4.7 Million Euro Brian J Tester, TURNEX Co-ordinator, ISVR, Southampton University Daniel Chiron, EC Project Officer

2 Status: Turbomachinery noise radiating from the bypass and core nozzles is becoming the dominant noise source on modern aircraft Problem: Research is needed to develop innovative concepts and enabling technologies to reduce aeroengine noise at source Scope of TURNEX TURNEX Objective: Improved understanding & validated design methods and evaluation of low-noise exhaust nozzle configurations aimed at a source noise reduction of 2-3dB.

3 Result from (FP5)

4 Research Objectives Acquire high quality experimental validation data on scaled exhaust models for exhaust fan tones and broadband noise, utilising simulated turbomachinery noise sources and innovative measurement techniques. Test experimentally at model scale innovative noise reduction concepts. To improve computational prediction methods for turbomachinery noise radiation through the engine exhaust and to validate these methods with the experimental data. To conduct a parametric study of real geometry/flow effects and noise reduction concepts as applied to current and future aircraft configurations. WP 1 Frank Arnold, RRD WP 2 Jean-Louis Migeot, FFT WP 3 Stephane Lidoine, AI-F

5 Validation, improvements WP 1 WP 2 Turbomachinery Exhaust Noise Experiments Noise reduction data Improved Models and Prediction Methods Improved and validated methods WP 3 Task 3.1 Parametric study of real geometry/flow effects and noise reduction concepts (Leader: RR) Task 3.2 Implementation of technology improvements by industrial partners (Leader: AI-F) Interrelations between Workpackages.

6 Partners ISVR (GB) - Project Co-ordinator Airbus France (FR) Dassault Aviation (FR) Rolls-Royce Deutschland (DE) Rolls-Royce UK (GB) Free Field Technologies (BE) DLR (DE) EADS-CRC (DE) National Aero Lab (NL) TU Eindhoven (NL) AVIO (IT) Middle East TU (TR)

7 WP 1: Experimental tests at model scale Experiments Validation data Innovative noise reduction concepts Conventional engine exhaust configurations Experimental Data for WP 2 and WP 3 Noise Test Facility (NTF) Anechoic Chamber for Validation Tests at QinetiQ

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9 Innovative noise reduction concept (1): Scarfed fan exhaust to partially shield observer on ground from fan noise

10 Innovative noise reduction concept (2): Afterbody Liner, exterior to bypass duct

11 WP 2: Improved Models and Prediction Methods Verify and validate a limited number of computational models and prediction methods that can be implemented and evaluated by the industrial partners in WP 3 - Simple configurations (1-5) - Lined afterbody for noise reduction Validated models for WP 3

12 TURNEX WP 2: Improved Models and Prediction Methods Verify and validate a limited number of computational models and prediction methods that can be implemented and evaluated by the industrial partners in WP 3 - Realistic configurations Mach y (m) x (m)

13 Analytic solution for near-field plane wave radiation from a circular duct (Munt model) CAA solution for same case (Actran/AE - frequency domain) Example of verification of CAA code with analytic Munt model showing refraction of plane wave in the near field

14 WP 3: Assessment and Industrial Implementation of Results Objectives Conduct a parametric study of real geometry and flow effects, such as shear layer refraction and flow-asymmetry with the validated models from WP 2. Investigate and evaluate the benefits of three noise reduction concepts: scarfed nozzles, an acoustically lined after-body and an acoustically lined wing with the experimental data from WP 1. Evaluate wing reflection installation effects with the aid of asymptotic methods. Introduce the key results into the current Aircraft Noise predictions tools in order to evaluate the impact of the TURNEX results on the total Aircraft Noise.

15 Conclusions At the half-way point TURNEX has produced the deliverables promised The design of the main 1/10 scale experiment is nearly completed and will be conducted in October, giving validation data for the CAA codes and noise reduction concepts Good progress has been made on two out of three noise reduction concepts: the After-body Liner ( AL ) and scarfed nozzles. Zero flow tests on the Happy After-body Liner ( HAL ) are imminent. The frequency domain CAA codes are being successfully verified with analytic models. A methodology for dealing with the unstable solutions in the time domain CAA codes is showing considerable promise

16 Exterior Acoustic Liner applied over 180 degrees to Afterbody Exterior Acoustic Liner applied over 180 degrees to Plug Nozzle Happy Afterbody Liner

17 Computational Aeroacoustics Enabler Development Idealised Calculation TRL 3 Idealised Validation TRL 4 Realistic Calculation TRL 5 Realistic Validation TRL 6 Turbomachinery Tones LEE & RANS Turbomachinery Broadband noise RANS LES/DES Mesh studies etc Flat plate Idealised source PROBAND Idealised source PROBAND Rotor alone & interaction noise PROBAND PROBAND VITAL PROBAND Propagation Potential flow - FE LEE Advanced Measurement Techniques Shear layer Inlet Inlet SILENCER MESSIAEN TURNEX TURNEX PROBAND Haystacking TURNEX TURNEX TURNEX Liner Impedance LINTEC LINTEC Jet Noise RANS Single stream jet JEAN Single stream jet JEAN Coaxial jet CoJeN Coaxial jet CoJeN LES/DES Airframe Broadband Noise Very low frequency JEAN Very low frequency CoJeN LEE & RANS NAtAN NAtAN LES/DES Turbulence Modelling OPERA FP4 FP5 FP6 FP7