Active Drag Reduction of Fastback MIRA Model Based on Steady Blowing

Abstract:

Low aerodynamic drag are of great significance for energy conservation and emission reduction of fuel vehicles， as well as increasing the range of electric vehicles. In recent years， the active jet technology is mostly applied to high aerodynamic vehicle models such as square back model， but its drag reduction and mechanism on low drag vehicles are not clear. In this paper， the effects of steady jet position， jet momentum coefficient and jet angle on drag reduction and net saving are studied， and the flow field analysis is given. The results show that the vertical rear jet （J3， J4， J5） of the fast back vehicle is an effective energy-saving measure， the low momentum coefficient has a good net saving rate， and the aerodynamic drag reduction and net saving rate have a maximum value with the change of jet angle. The best working condition to get the back jet in the end is： J3， J4 and J5 jet grooves arranged at the tail of the model are used for jet，the momentum coefficient is 1% and the jet angle is 45 °， the aerodynamic drag was reduced 2% and the net saved energy can reach 9.5% and 129.7W， respectively.

Key words:fastback MIRA model;steady blowing;drag reduction;active control