Aero-engine manufacturers have so far been able to considerably reduce jet noise by increasing bypass ratios. Further progress on noise reduction now depends on a detailed understanding of the exact noise-generation mechanisms.
It is widely recognised that both large-scale structures and fine-scale turbulence contribute to the overall sound radiated from subsonic jets, and that there is an additional noise source associated with the flow separation over the sharp corner that occurs in the region near the nozzle exit. However, previous simulations of jet noise have not been able to include all possible noise-generation mechanisms. In the current project, the recent increase in computing power will be exploited to perform DNS of fully turbulent high-subsonic Mach number jets that include the nozzle using a computational domain large enough to directly compute part of the far-field sound. With such a direct simulation approach, all possible noise-generation mechanisms will be included.
Technological advantages of the proposed active control method
Technology Road Map
2007-2012: Code development funded by Royal Academy of Engineering and EPSRC research fellowship (EP/E504035/1): ‘Numerical investigation of the hydrodynamic and acoustic fields of compressible axisymmetric flows’
2011-2011: CRAY Centre of Excellence: code optimization for many core platforms
2013-2018: Further code development and optimisation of code through EPSRC grant (EP/L000261/1): UK Turbulence Consortium
Collaboration opportunity
The code can be adapted to a number of other geometrical configurations, and flow and noise control strategies can be tested using this virtual wind tunnel approach.
If you would like to know more, please contact Neil Sandham n.sandham@soton.ac.uk
Current project funding: UK Turbulence Consortium (EPSRC: EP/L000261/1), July 2013-June 2018