基于定常射流的快背式MIRA车型主动气动减阻

Active Drag Reduction of Fastback MIRA Model Based on Steady Blowing

摘要:

低风阻对燃油汽车节能减排和增加电动汽车续航里程具有重要意义。近年来，主动射流技术已用于汽车减阻研究中，但多是针对方背体等高风阻车体模型开展。本文以MIRA快背式车型为对象，研究车辆背部定常射流的布置位置、射流动量系数和射流角度对减阻量和净节率的影响规律，并给出了流场分析。结果表明：快背式车型垂直尾部射流（J3、J4、J5）是有效的节能措施，低动量系数具有较好的净节率，气动减阻量和净节率随射流角度变化存在极大值；最大减阻主动射流工况是对垂直尾部（J3、J4、J5）射流槽进行射流、动量系数1％、射流角度为45°时，其减阻量为2%，对应净节率129.7 W。

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.