Computation of High-Speed Coaxial Jets with Fan Flow Deflection

• Published in: AIAA journal 2010-10, Vol.48 (10), p.2249-2262
• Main Authors: Xiong, Juntao, Nielsen, Preben, Liu, Feng, Papamoschou, Dimitri
• Format: Article
• Language: English
• Subjects: Acoustics; Aeroacoustics, atmospheric sound; Aerodynamics; Air flow; Aircraft; Exact sciences and technology; Experiments; Fluid dynamics; Fundamental areas of phenomenology (including applications); Noise (turbulence generated); Physics; Simulation; Turbulence; Turbulent flows, convection, and heat transfer
• ISSN: 0001-1452; 1533-385X
• DOI: 10.2514/1.J050331

We present a computational study, validated by mean-flow experiments, of a dual-stream nozzle simulating the exit conditions of a supersonic turbofan engine with noise-suppressing fan flow deflectors. The study is conducted for eight nozzle configurations and two operating conditions: a cold condition at which mean velocity surveys were conducted and against which the computational code was validated and a hot condition that corresponds to the takeoff engine cycle and at which acoustic data were collected. The code predictions successfully replicate the mean velocity fields and the inflectional layers of the experimental flows. The code is then extended to the conditions of the actual engine cycle. The computations reveal a similar velocity profile for the hot and cold conditions when the axial distance is normalized by the potential core length. For both conditions, the vane deflectors reduce the turbulent kinetic energy k on the underside of the jet. An overall noise source strength is modeled as the axial integral of k... A significant correlation is found between the reduction in the noise source strength and the reduction in the peak level of the overall sound pressure level. (ProQuest: ... denotes formulae/symbols omitted.)