Body design is a lot of knowledge, one of the important content is the drag problem.
Usually means that the drag cars are mostly produced by interaction of external and airflow resistance. In fact, the air flowing through the vehicle’s interior is also driving the car constituted resistance. The results show that the role of resistance in the car by 5-part.
First, the shape resistance, the motor vehicle front body positive pressure and negative pressure difference between the rear of the formation of resistance, about 58% of the air resistance;
Second, interference resistance, outstanding surface of the motor vehicle parts, such asBumper, Mirrors, front license, drainage channels, chassis and other transmission interference caused by air resistance produced, accounting for 14% of the air resistance;
Third, the internal resistance of the motor vehicle interior air flow, cooling the engine air currents caused by the resistance, about 12% of the air resistance;
Fourth, the lift produced by the high speed caused by the resistance, aerodynamic drag accounts for about 7%;
Fifth, the friction of the air flow relative to the body, accounting for 9% of the air resistance;
For the first, two kinds of resistance, the car body design should be streamlined as much as possible, not too much cross-sectional area, body parts with the appropriate arc transition, to minimize the outstanding body attachment, front face, the engine hatch, before the wind Tilt the glass properly, the rear window, after the roof of the length, angle of the design should be appropriate. In addition, you can install in place deflector or spoiler. By studying the airflow car outside the law can not only design a more reasonableBody structureCan also be cleverly steering flow, the appropriate use of the scouring action of the local airflow to reduce car off the dust deposition.
For the fourth resistance, to try to reduce the moving lift, including the former low after the high strings, backplanes upturned tail of the appropriate installation guide plate and the spoiler and other measures.
Part of the external air is introduced vehicle’s interior, may be reduced to some extent, the external air flow resistance of the car, but the air in the internal airway through the friction generated when, vortex losses. Flow of vehicles within the law, you can try to reduce internal air resistance, effectively cooling and ventilation. Use of air distribution, but also skillfully arranged inlet of the engine high pressure areas, to improve intake efficiency and reduce the pressure near the vortex, while the exhaust port area of low pressure scheduled to make the exhaust more smoothly.
Careful readers may have noticed, the above discussion with a number of non-restrictive terms, such as “appropriate” to use five times. Some readers may want to use some precise figures to express, such as the backward angle, fillet radius and so on. This involves the overall design concept of the body. Drag the whole structure is built on the concept car, a model car the best geometrical parameters, in the other models are not applicable. A small change is often a huge impact on the overall, is the so-called affect the situation as a whole. The data on technical books are strictly defined test conditions, the specific range of vehicles for test results. Without these preconditions, the data is ridiculous.
In order to reduce air drag coefficient, the shape of future models will be used to smooth curves to smooth the transition line blanking the car body. Wai Wai front and side, front wall, side panels and hood, and side after the Wai Wai are used in places smooth transition, under the hood tilt forward, the rear cover after a short while Gao Qiao, Ji daughter board back after contraction, using a large curved glass windshield, and the smooth transition with the roof, front windscreen and the horizontal angle is generally between 25 degrees -33 degrees, the phase level and the body side, front and rear lamps, door handle embedded in car body, body surface smooth and bright and clean as possible, the vehicle covered with a flat cover, lower the wholeHeightDegrees, etc., these measures will help reduce air resistance coefficient.