Summary
The phenomenon commonly known as “wind buffeting” when you roll down a car window is formally termed Helmholtz Resonance, named after German physicist Hermann von Helmholtz. This effect occurs when you open a single window in a moving car. This causes irritating pulses of wind and pressure shifts within the cabin. Helmholtz Resonance is similar to blowing into an empty bottle to produce sound. The air rushing past the open window creates vortexes that compress and decompress the air rapidly.
The low tone produced by Helmholtz Resonance, typically around 20Hz, is close to the lower limit of human hearing and can sometimes be felt as vibrations in the body. Modern car designs, aimed at improving aerodynamics and reducing noise, exacerbate this effect by creating smoother airflow around the vehicle, which amplifies wind buffeting when a window is opened.
Front windows are less affected due to the design and positioning of side-view mirrors, which help control airflow. However, rear windows are more prone to generating Helmholtz Resonance as their airflow remains uncontrolled.
While certain design features like pop-up deflectors on sunroofs can mitigate wind buffeting, the most effective solution remains the same: either roll up the offending window or open another window to relieve air pressure in the cabin. Additionally, window locks can prevent unwanted window adjustments, ensuring a more comfortable ride for passengers of all ages.
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