Combustion Noise Prediction Using Linearized Navier–Stokes Equations and Large-Eddy Simulation Sources

Ullrich, Wolfram C.; Hirsch, Christoph; Sattelmayer, Thomas; Lackhove, Kilian; Sadiki, A.; Fischer, André; Staufer, Max

doi:10.2514/1.b36428

“…7, respectively [1,38]. The validity of this model for the nozzle was proven in previous studies [25,29]. All walls are characterized by slip boundary conditions, i.e.û • n = 0 , as viscosity can most probably be neglected in the low frequency range.…”

Section: Rans/lnse-approachmentioning

confidence: 71%

“…Furthermore the Artificially Thickened Flame (ATF) procedure is applied. More details about the simulation model can be found in [29].…”

Section: Incompressible Les (Precise-uns)mentioning

confidence: 99%

See 1 more Smart Citation

Prediction of Combustion Noise in a Model Combustor Using a Network Model and a LNSE Approach

Ullrich

¹

,

Mahmoudi

²

,

Lackhove

³

et al. 2017

Journal of Engineering for Gas Turbines and Power

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The reduction of pollution and noise emissions of modern aero engines represents a key concept to meet the requirements of the future air traffic. This requires an improvement in the understanding of combustion noise and its sources, as well as the development of accurate predictive tools. This is the major goal of the current study where the low-order thermo-acoustic network (LOTAN) solver and a hybrid computational fluid dynamics/computational aeroacoustics approach are applied on a generic premixed and pressurized combustor to evaluate their capabilities for combustion noise predictions. LOTAN solves the linearized Euler equations (LEE) whereas the hybrid approach consists of Reynolds-averaged Navier–Stokes (RANS) mean flow and frequency-domain simulations based on linearized Navier–Stokes equations (LNSE). Both solvers are fed in turn by three different combustion noise source terms which are obtained from the application of a statistical noise model on the RANS simulations and a post-processing of incompressible and compressible large eddy simulations (LES). In this way, the influence of the source model and acoustic solver is identified. The numerical results are compared with experimental data. In general, good agreement with the experiment is found for both the LOTAN and LNSE solvers. The LES source models deliver better results than the statistical noise model with respect to the amplitude and shape of the heat release spectrum. Beyond this, it is demonstrated that the phase relation of the source term does not affect the noise spectrum. Finally, a second simulation based on the inhomogeneous Helmholtz equation indicates the minor importance of the aerodynamic mean flow on the broadband noise spectrum.

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“…For complex flows, low-pass filtering in the spectral space is used, and low-pass filtering in the physical space is implemented by integration. In the fluid physical space D, the filtering function is G(x), and the filtering of the flowing turbulent pulsation f(x) is as follows [35], [36]:…”

Section: A the Les Methodsmentioning

confidence: 99%

Modeling and Measurement Study for Wind Turbine Blade Trailing Edge Cracking Acoustical Detection

Zhang

¹

,

Cui

²

,

Xue

³

et al. 2020

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The rapid deployment of the offshore wind turbine technology has brought more requirements for remote turbine health monitoring especially for blade health conditions. The trailing edge cracking (TEC) is often the early stage blade health issue which leads to more serious problems and even crash of wind turbine. In response to this cracking issue, this paper presents aero-acoustic noise modeling analysis of the blade airfoil section with and without cracking of typical 3 millimeter (mm) gap in the trailing edge and a comparative study between the simulation and semi-empirical model for the calculation aero acoustic characteristics (AACs) of airfoil TEC noise, and description a new acoustical sensor detection technology of blade TEC. The IEEE P2400 standard will be utilized to complete the acoustical signal calculation for rotating sound source and compared with other existing measured acoustical signals from on-site microphone. Several simulations are presented to test and validate the proposed model and analysis methods, demonstrating this research work cannot only analyze the AACs of the blade TEC detection, but will also contribute the complete wind turbine blade health monitoring technologies. INDEX TERMS Aero acoustic noise, acoustical detection, semi-empirical model, CFD simulation, wind turbine blade cracking. NOMENCLATURE A nomenclature list, if needed, should precede the Introduction. , Components along the x, y direction , Fluid density and pressure '' Homogeneous parts in the sub-grid scale mesh)* Rate of strain M Mach number of air relative to the blade The chord of blade section Angle of attack (AOA) , The pressure sides The suction sides Pe Effective sound pressure value Pref Reference sound pressure value Superscripts − Filtered variable. The derivative of the variable YAN LIU received the Ph.D. degree from the North China Electric Power University, Beijing, China. His research interests include optimization analysis of wind field and aerodynamics. YU XUE received his PhD degree from University of Minnesota, Aerospace Engineering and Mechanics, in 1994. He currently is the professor at Ocean University of China, Measurement and Control Department, he was ex-chief specialist of wind energy research at CDT Renewable Energy Research Institute, and he was the chief editor for IEEE 2400 "Wind Turbine Aero Noise Measurement Technique".

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“…The volume source spectrum is transformed to an equivalent heat release spectrum by exploiting Eq. (4) [29]. The compressible LES was jointly performed by CERFACS and CNRS [18,19,21] using the solver AVBP developed by CERFACS [17].…”

Section: Incompressible Les (Precise-uns)mentioning

confidence: 99%

Prediction of Combustion Noise in a Model Combustor Using a Network Model and a LNSE Approach

Ullrich

¹

,

Hirsch

²

,

Sattelmayer

³

et al. 2017

Volume 4B: Combustion, Fuels and Emissions

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0

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The reduction of pollution and noise emissions of modern aero engines represents a key concept to meet the requirements of the future air traffic. This requires an improvement in the understanding of combustion noise and its sources, as well as the development of accurate predictive tools. This is the major goal of the current study where the LOTAN network solver and a hybrid CFD/CAA approach are applied on a generic premixed and pressurized combustor to evaluate their capabilities for combustion noise predictions. LOTAN solves the linearized Euler equations (LEE) whereas the hybrid approach consists of RANS mean flow and frequency-domain simulations based on linearized Navier-Stokes equations (LNSE). Both solvers are fed in turn by three different combustion noise source terms which are obtained from the application of a statistical noise model on the RANS simulations and a postprocessing of an incompressible and compressible LES. In this way the influence of the source model and acoustic solver is identified. The numerical results are compared with experimental data. In general good agreement with the experiment is found for both the LOTAN and LNSE solvers. The LES source models deliver better results than the statistical noise model with respect to the amplitude and shape of the heat release spectrum. Beyond this it is demonstrated that the phase relation of the source term does not affect the noise spectrum. Finally, a second simulation based on the inhomogeneous Helmholtz equation indicates the minor importance of the aerodynamic mean flow on the broadband noise spectrum. NomenclatureA Area, m 2 c Speed of sound, m/s c p , c v Specific isobaric and isochoric heat capacities, J/(kgK) δ f Flame thickness in network model, m f Frequency, Hz F Fourier transformation, 1/Hz h 0 f ,k Enthalpy of formation of k-th species, J/(kgK) η Dynamic viscosity, kg/(m s) H u Lower heating value, J/kg i Imaginary unit k Wave-number, 1/m κ Isentropic exponent l Length, m λ Thermal conductivity, W/(m K) M Mach numbeṙ m Mass flow rate, kg/s n Surface normal p Pressure, N/m 2 φ Arbitrary field quantity * Address all correspondence to this author. GTP-16-1249, Ullrich, page 2 P ± Complex pressure amplitude, N/m 2 q V Volumetric heat release, W/m 3 Q Integral spectrum of fluctuating heat release, W/Hz ρ Density, kg/m 3 s Specific entropy, J/(kgK) s V Volume source, 1/s S V Integral spectrum of the fluctuating volume source, 1/s t Time, s T Temperature, K u Velocity vector, m/s ω Circular frequency, 1/s x Position vector, m Z Reduced (non dimensional) impedance IntroductionIn the near future the air traffic is expected to increase significantly which makes a further reduction of aircraft noise indispensable. This must address all aircraft components, but particularly the engine, in order to meet strict political requirements such as the ACARE 1 goal prescribing a noise reduction of 50% by 2020. Combustion noise is becoming increasingly important as a major noise source in aircraft. This is partially because advances in the design of a...

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Combustion Noise Prediction Using Linearized Navier–Stokes Equations and Large-Eddy Simulation Sources

Cited by 8 publications

References 46 publications

Prediction of Combustion Noise in a Model Combustor Using a Network Model and a LNSE Approach

Prediction of Combustion Noise in a Model Combustor Using a Network Model and a LNSE Approach

Modeling and Measurement Study for Wind Turbine Blade Trailing Edge Cracking Acoustical Detection

Prediction of Combustion Noise in a Model Combustor Using a Network Model and a LNSE Approach

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