Abstract
To realize better air-conditioning performance, the location and shape of registers should be
optimized with close examinations on the airflow in cabin at the first stage of the designing.
Then, we have tried to develop a practical method to predict airflow velocity in a car cabin by
using CFD.
Our simulation model includes the steering and levers, because their locations influence the
jet flow from registers toward occupants. To precisely predict the jet flow and its diffusion,
we have arranged calculation mesh adequately and adopted the realizable k- model as a
turbulence model.
Consequently, a practical method has been successfully developed to predict the average
airflow velocity around occupants and the average jet diffusion velocity to the rear seat with
an error ratio of less than 10%. By this method, furthermore, the influence of steering on the
airflow was confirmed.
Keywords - CFD, airflow, turbulence model, air-conditioning, measurement