Acoustic complex pressure distribution on the duct wall opposite to the acoustic liner sample was obtained from grazing flow duct test with and without flow. Based on the test model and data

sound prediction study was carried out to validate the 2D and 3D duct sound propagation models. Result showed that 2D and 3D prediction results were very consistent

especially in the absence of flow. Duct sound propagation predictions were well matched to the corresponding grazing flow test results with and without flow at different frequencies

which verified the sound propagation model accuracy. Considering the influence of flow and frequency

the error between prediction and test results with flow was bigger than the situation without flow

and error at low frequency was bigger than that at high frequency.