Acoustic Comfort: Comfort Helmet
The comfort level of passengers in convertible cars (open roof cars) can be evaluated using a special helmet, called "Comfort Helmet", fitted on the head of a dummy. This helmet is equipped with eight omni-directional sensors in appropriate positions on the helmet. Since the sensors are film-type, they have a high frequency response.
In approximately a minute, the mean value and the standard deviation of the velocity are measured by each sensor. This gives a clear indication of the local flow velocities and of the turbulence levels around the passenger's head.
Therefore, this measuring technique allows for the evaluation of the flow characteristics (presence of buffeting, ...) and the subsequent optimization of the comfort level within the passenger compartement.
An example of buffeting around the driver's head using a "Comfort Helmet " is shown below.
Look at the maps of mean velocity and standard deviation on each point of the Helmet in the base Wind Tunnel and with the Turbulence Generators.