DARP: HPCx Resources for MSTTAR DARP Research Response 4: Blade and Cavity Noise

Direct simulations of the broadband noise generated by turbulent flow over blades will be validated against experiment and then used to provide fundamental insight into sound generation mechanisms. An existing complex-geometry parallel DNS/LES code, previously used for studies of transitional separation bubbles and jet aeroacoustics, will be applied to a blade geometry. Incorporation of suitable Ffowcs Williams-Hawkins (FW-H) surfaces will allow acoustic sources to be characterised according to type (shear stress dipole, Reynolds stress quadrupole, trailing edge scattering) and Icoation (e.g. flow separation, trailing edge), as has been done previously for turbulent channel flows. The proposed aerofoil simulations are at the limit of what is possible computationally, and will require significant use of the HPC(x) supercomputer facility currently under procurement by EPSRC.The simulation programme for cavity flow will focus on the QNET Application Challenge D30, which is derived from the M219 cavity test case studied in the ARA transonic wind tunnel. The intention is to provide quality reference simulations at higher resolution than previously attempted and to evaluate cheaper methods based on unsteady RANS. The simulation will be performed using a parallel high-order code based on optimised compact schemes. This numerical algorithm and program have already been tested against a series of test cases. including aeroacoustic problems.