Direct noise simulation of flow induced whistle

In this study the attention was focused on a secondary noise source of the vehicle such as the refrigerant system. The problem was initially described as an annoying whistle noise, which was clearly audible inside a vehicle cabin. The issue frequency identification through time-frequency plots showed a typical acoustic resonance occurring along the refrigerant gas duct, at a specific flow speed. This phenomenon was worsening significantly the sound quality of the vehicle interior noise.