Abstract
Aerodynamic properties of heavy-duty trucks are modified with wind tunnel tests and numerical simulations. Since the Reynolds number of trucks are very high, the Reynolds number of the wind tunnel tests with the small scale models is smaller than those of real trucks. In this paper, we discuss the effect on trubulence of the aerodynamics performance of the small scale models. The flow-fields of the small scale models with turbulence grid were similar to those of the large scale models. That is the practical Reynolds number of the wind tunnel test with turbulence grid was higher than geometric Reynolds number. This result indicated that turbulence grid was useful to estimate aerodynamics performance of large scale vehicles by using small scale models.
