Stripping one-dimensional acoustic pressure response into propagating- and standing-wave components

Most realistic boundary conditions are partially absorptive, with the rest of the incident acoustic power being reflected. This results in a response that can be viewed as a summation of propagating- and standing-wave effects. A one-dimensional, measurement-based, two-microphone spectral analysis technique is developed which s_eparates the t_otal acoustic r_esponse i_nto p_ropagating and s_tanding (STRIPS) wave components. STRIPS uses measurements that contain implicit information about the boundary condition to extract the propagating- and standing-wave components. These sum to be the total system response without requiring explicit knowledge of the particular boundary condition. An exact decomposition example for a one-dimensional acoustic pressure model with a known mixed boundary condition is used to validate the STRIPS method. The utility of the STRIPS method is demonstrated using experimental measurements from a tube as input to STRIPS to obtain the propagating- and standing-wave pressure components. Changes in experimental boundary absorptivity are seen in the STRIPS results when a flared end is attached to the tube.