A low frequency model for the aeroacoustic scattering of cylindrical tube rows in cross-flow

Heat exchanger tube rows can influence the thermoacoustic instability behaviour of combustion systems since they act as both acoustic scatterers and unsteady heat sinks. Therefore, with careful tuning their properties, exchangers have potential to passive control devices. In this work, we focus on (only) scattering tubes. We present a comparison existing models for slits, latter having advantage incorporating frequency dependence. then propose new model that enables adaptation slit rows. This is validated against experiments Linearised Navier Stokes Equations (LNSE) predictions transmission reflection coefficients, including phase information. The show very good agreement experimental numerical validations, especially low frequencies (Strouhal number < 0.5, based radius excitation frequency), mean differences less than 2% coefficients (the coefficient errors are somewhat larger magnitudes close zero).