Broadband Combustion Noise Simulation of Open Non-Premixed Turbulent Jet Flames

• Published in: International journal of aeroacoustics Vol. 11; no. 1; pp. 1 - 24
• Main Authors: Mühlbauer, Bernd, Ewert, Roland, Kornow, Oliver, Noll, Berthold
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.03.2012
• Subjects: Combustion; Computational fluid dynamics; Computer simulation; Fluid flow; Mathematical models; Noise; Turbulence; Turbulent flow; turbulence; combustion noise; stochastic source reconstruction
• ISSN: 1475-472X; 2048-4003
• DOI: 10.1260/1475-472X.11.1.1

Numerical broadband combustion noise simulations of open non-premixed turbulent jet flames applying the Random Particle-Mesh for Combustion Noise (RPM-CN) approach are presented. The RPM-CN approach is a hybrid Computational Fluid Dynamics/Computational Aeroacoustics (CFD/CAA) method for the numerical simulation of turbulent combustion noise, based on a stochastic source reconstruction in the time domain. The combustion noise sources are modeled on the basis of statistical turbulence quantities, for example achieved by a Reynolds averaged Navier-Stokes (RANS) simulation, using the Random Particle-Mesh (RPM) method. RPM generates a statistically stationary fluctuating sound source that satisfies prescribed one- and two-point statistics which implicitly specify the acoustic spectrum. Subsequently, the propagation of the combustion noise is computed by the numerical solution of the Linearized Euler Equations (LEE). The numerical approach is applied to the DLR-A, the DLR-B and the H3 flames. The open non-premixed turbulent jet flames differ in the mean jet exit velocity, therefore in their respective Reynolds number, and in the fuel composition. Computed radial profiles of the reacting flow field are compared to experimental data and discussed. Computed sound pressure level spectra of the DLR-A and DLR-B flames and acoustic intensity level spectra of the H3 flame at different microphone locations are presented and compared to measurements.