The usefulness of hybrid modelling strategies for acoustic flows is being examined by Dr Adrian Harwood and Dr Iain Dupere. We have shown that for a number of scenarios where there is a near field source and a far-field observer adjacent to a compact body, the specific approximation to the Green's function (known as the compact Green's function) for the Helmholtz equation can be computed numerically. The numerical Green's function may then be passed to an acoustic analogy for solution of the far-field sound.
An existing software package has been used to transform a more complex physical domain into a simplified computational domain where potential flow solutions may be easily computed over a grid of points. If the appropriate computational domain is chosen for the transformation, the potential flow solutions may be used without modification to compute the compact Green's function in the physical domain and significant sources of error are avoided.
We have established links with the SAFARI team at EDF R+D and the Computational Aeroacoustics group at the University of Cambridge led by Paul Tucker.