| Nowadays, the crisis of energy is becoming more severity around the world. The development of freeways, as well as new productions and technology which are introduced from developed countries improve the technologies of automobiles. These factors make the velocity of many kinds of automobiles faster and faster on freeways. The improving of velocity causes prodigious augment of the drag, which makes oil wear add more. Because the oil wear of automobiles has big scales in national oil wear, the research of cutting down the drag are more and more important along with the crisis of energy becoming more severity.This paper mainly researches the effect and mechanism of some affixations which can reduce the drag of Panel Vans. It also quests for the size of these affixations and the infections to aerodynamic quality along with the changes of affixations' position. Another aim is finding out the best assemble scale of these affixations, which can offer advantage to the optimize design of vans.Automobile aerodynamic methods mainly include: theory analysis, examinational research and computation of numerical simulation. This paper analyzes the problems deeply using these methods. Also this paper analyzes and derives the relations between flowing phenomena and dynamical and educes the conclusions that can direct the improvement of the design.In order to achieve the aims of the research, this paper studies aerodynamic quality of vans in several ways:Firstly, according to the wind tunnel test, the paper analyzes the influencing principles on aerodynamic quality from the dome on the operator cabin, which offers theories to the improvement of the dome's shape and setting. According to the difference between the data of wind tunnel and numerical simulation, this paper validates the consistency of the dome's effects of two different methods, which explains the method of numerical simulation is rational and veracious.After validating the veracity of numerical simulation, this paper computes the effect of van's exterior flow field from the Side Plate. According to the differences of van's coefficient drag between the instances with and without Side Plate when there is the crosswind or not, this paper studies the Side Plate's aerodynamic quality and principle of anti-drag. Without goods, the height of boxcar will fall down and the Dome can't be taken down, so the Dome has bad effect on anti-drag. This paper researches a newequipment that can be taken down easily——the Damper Plate. Its structure is simplerand the scale of capability and price is better than the dome's. In base of comparing the different effect between the Damper Plate and the Dome, this paper researches the effect on van's exterior flow field from the Damper Plate and analyzes the principle of anti-drag. The comparison of the Damper Plate's advantage and shortage offers the theoretical supports to the vans' optimize design .In the research of the Damper Plate, there are three factors——height, breadthand position. The paper studies the best condition of these factors using the orthogonal experimental design method and finds the best condition is that the height is 40.8mm,the breadth is 178mm and the dimension of position is 20mm.According to the systemic analysis on the data from tests and computations, this paper studies the flowing characteristic of van's exterior flow field and makes sure of the leading factors of van's drag and the complicated connection among parameter of van's shape, flowing characteristic and the drag. All these offer important references for the vans' optimize design. |
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