Abstract
The current air diffusion in car cabin is generally realised by several air grids which provide to the passengers local air flux at high speed. The system is designed to offer air flow rate for all passengers, adjustable in level, orientation and temperature. Basically the current HVAC-systems dont answer totally to passenger thermal comfort distribution around the body or to different climate responses for front and rear passengers.
The innovative system presented in this article fights these drawbacks by offering an additional
soft air diffusion which provides homogeneous climate in the cabin and new thermal sensations to passengers.
After describing the concept, well analyse the methodology used for the definition and design of the product. Well present how to determine the significant parameters for our system in order to design the optimal concept. For this, 3 tools were used: measurements, CFD simulation and a people jury.
In a second step, well focus on the comfort validation process and the associated experimental procedure. The comfort validation based on thermal, air distribution and acoustic characteristics, is split between transient (specially cool down test) and steady state phases. For each situation, the comfort criteria in air velocity field, temperature and acoustic are specified.
The last paragraph will illustrate the results obtained in the car prototype equipped with our soft diffusion concept, by measurements, specially with the Renault thermal manikin and subjective evaluations.
Well conclude with the prospects and the potential of innovation to go always further in human well-being achievement.