Impact of relative position vehicle-wind blower in a roller test bench under climatic chamber

A steady state three-dimensional CFD model was developed and applied to the estimation of the air velocity and temperature profiles inside of a climatic chamber equipped with a vehicle roller (chassis dyno) test bench. The simulations reproduce one steady-state condition from NEDC, specifically the EU17 mode (120 km/h, maximum velocity during the cycle). The cool air propelling temperature was 20 °C (minimum temperature in the NEDC range). Simulations were performed employing the Reynolds-Averaged Navier-Stokes (RANS) approach with the realizable k-ε model to provide closure. Air velocity and air temperature distributions for the cases of study are shown. Results show that the effect of relative vertical position between the wind simulation blower and the vehicle on the temperature of the air flow below the vehicle tested is not negligible. This suggests revising the certification cycle in order to adapt the position of the air blower according to the height of the vehicle.