An Experimental Study of Tractor Base Bleed for Heavy Vehicle Aerodynamic Drag Reduction
An Experimental Study of Tractor Base Bleed for Heavy Vehicle Aerodynamic Drag Reduction
复制标题
拖拉机底部排气重型车辆气动减阻试验研究
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
K. Salari
中科院分区：
文献类型：
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作者：
B. Storms;J. Ortega;K. Salari
造成重型车辆气动阻力的一个重要因素是牵引车与挂车之间的间隙，尤其是在侧风条件下。在这种情况下，自由流进入牵引车-挂车间隙，给车辆带来动量交换，随后增加气动阻力。在目前的普遍应用中，拖拉机侧扩器可以显著降低阻力，但也存在一些问题。当牵引车相对于拖车急剧旋转时，侧增力器经常损坏，可能会产生额外的维护和修理费用。这个问题可以通过缩短扩展器（从而减少它们的好处）或设计另一种减少阻力的概念来缓解。其中一个概念是拖拉机底部放气，其中气流通过拖拉机后部排放到拖拉机-拖车间隙中。为了研究这一概念，在基于宽度的雷诺数为42万的情况下，对通用1:20比例的拖拉机-拖车结构进行了风洞研究。通过嵌入在牵引器底部的多孔材料输送，流量变化，从而产生牵引器后的速度，范围从0到10%的自由流速度。在两种不同的牵引车-挂车分离距离下，研究了有无侧扩器的配置。
A significant contributor to heavy-vehicle aerodynamic drag is the tractor-trailer gap, especially when operating in a crosswind. At this condition, the freestream flow turns into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the aerodynamic drag. In common use today, tractor side-extenders provide significant drag reduction, but they are not without problems. Frequently damaged when the tractor pivots sharply with respect to the trailer, side extenders can incur additional costs for maintenance and repair. This issue can be alleviated by shortening extenders (thereby reducing their benefit) or devising an alternative drag-reduction concept. One such concept is tractor base bleed, in which air-flow is vented into the tractor-trailer gap through the back of the tractor. To study this concept, a wind-tunnel study was conducted for a generic 1:20-scale tractor-trailer configuration at width-based Reynolds number of 420,000. Delivered through a porous material embedded in the tractor base, the bleed flow was varied so as to generate velocities behind the tractor ranging from zero to 10% of the freestream velocity. Configurations were studied both with and without side extenders at two different tractor-trailer separation distances.