1. Tunnel
Cars wind tunnel
is used to produce automotive wind tunnel airflow conduit artificial (man-made wind). In this region of the pipeline section can cause the flow of air evenly, car wind tunnel test proceeds in this wind tunnel.
Cars wind tunnel – Overview
is used to generate an artificial air flow conduit (artificial wind). In this region of the pipeline section can cause the flow of air evenly, car wind tunnel test proceeds in this wind tunnel. Automotive wind tunnel used to produce powerful airflow fan is great, such as Mercedes-Benz automobile wind tunnel fan diameter reached 8.5m, driving the fan motor power up to 4000kW, wind tunnel test section used for real car the air flow rate up to 270km / h. Build a car of this size often wind tunnel would cost hundreds of millions of dollars, or even more than 10 million, and each do a wind tunnel test car cost is quite large.
car model wind tunnel wind tunnel there, real vehicle wind tunnel and climatic wind tunnel, wind tunnel model is much smaller than the real vehicle wind tunnel, and the use of its investment costs are relatively small. In the wind tunnel model of scale models can be tested and the accuracy is also relatively lower. Real vehicle wind tunnel is a large, high construction costs and usage charges. Currently real car in the world is not much wind tunnel, mainly in Japan, the United States, Germany, France, Italy and other countries of the big car companies.
automotive wind tunnel – technology development history
In 1871 the British built the world’s first recognized a wind tunnel. American Wright brothers (O.Wright and W.wright) manufactured in 1901 a square test section 0.56 m, wind speed 12 / s wind tunnel, and then invented the world’s first practical airplane in a 1903. Large numbers of wind tunnel is in the middle of the 20th century.
1932 Swiss Patent Acre (G.Ackttet) built the world’s first supersonic wind tunnel test section area of 0.4 m times; 0middot; 4 meters, the Mach number (the wind speed ratio and the speed of sound) 2, then the main effect for aerodynamic research and testing supersonic flow shells designed .
1956 to adapt to the development transonic and supersonic aircraft, the United States built the world’s largest transonic and supersonic wind tunnel, test section area of 488 m times; 4.88 meters Mach 0.8-4.88, power 161 000 Kw.
In 1958, NASA completed the test section diameter of 0.56 meters, the Mach number can be as high as 18-22 hypersonic wind tunnel. In 1980, the United States will be an old low-speed wind tunnel transformed into the world’s largest full-size wind tunnel (prototype aircraft can be directly put into the test section of hair), the test section area of 24.4 m times; 12.2 meters and wind velocity 150m / s, power 100,000 Kw.
In 1975, the British built a low pressure wind tunnel test section 5 m times; 4.2 meters Winds 95-110m / s, a pressure of 3 atmospheres, 14,000 kW of power, test Reynolds number (which is a dimensionless number) 8times; 106.
1980, the United States into a cryogenic tunnel to nitrogen gas (nitrogen low freezing point, adapted to operate at a low temperature) as the working medium temperature range 340-78K, up to 9 atm pressure, 2.5 m test section times; 2.5 m 0.2 to 1.2 Mach, Reynolds up 120times; 106.
In 1977, China Aerodynamics Research and Development Center, build Asia’s largest low-speed wind tunnel, test section tandem double: 8 m times; 6 m and 16 m times; l2 meters, wind speed 100m / s, power 7800kW .
Cars wind tunnel – Principle
is capable of doing tunnel generation and control airflow, aircraft or objects to simulate the flow of ambient gas, and gas flow measurements of the object a pipe-like effect and physical phenomena observed experimental equipment, which is the most common aerodynamic experiments, the most effective tool. Wind tunnel experiment is an indispensable component of development work in the aircraftMinute. It not only plays an important role in research and development in aerospace engineering, aerodynamics with the development of industry, in transportation, housing construction, wind energy utilization and environmental protection departments have also been more widely used. Based on wind tunnel to experiment with is the principle of relativity movement.
Tunnel car – classification model and full-size wind tunnel tunnel
Airflow Test to wind sieve openings 1: 1 model (full size model) or eukaryotic vehicle wind tunnel is called ldquo; full size wind tunnel test rdquo ;, is called the compression ratio ldquo wind tunnel model or a smaller size parts; wind tunnel rdquo ;. Japan and the former Soviet Union more than a 1: 5 scale model; United States and Europe more than 1: 3 or 1: 4 scale model. At present (refer to 2009) around the world, nearly 30 full-size wind tunnel can be used to test the car.
weather wind tunnel, the acoustic wind tunnel, wind tunnel aerodynamic
weather wind tunnel (tunnel or climate) may vary air flow temperature, humidity, light intensity, and other weather conditions (rain, snow, etc.); acoustic wind tunnel in the construction process using a variety of noise reduction measures, the background noise is very low, can be separated and measure the aerodynamic noise generated by cars. Both collectively referred to as special wind tunnel wind tunnel. The rest are usually wind tunnel aerodynamic wind tunnel. In recent years, the new wind tunnel, are pneumatic / acoustic wind tunnel, or pneumatic / climatic wind tunnel, even pneumatic / acoustic / climatic wind tunnel, also known as multi-purpose type of wind tunnel wind tunnel.
Experimental Section Size
A cross-sectional area Slt; 10 square meters of the wind tunnel (including scale model wind tunnel and air tunnel), some small orifice weather wind tunnel, the air is mainly used to heat directly to the surrounding area of the engine compartment concentration tested. As MIRA wind tunnel model. One is 10le; Sle; 30 square meters tunnel. This is mainly used for wind tunnel testing all kinds of cars and other small vehicles (real vehicle test). Such as the Toyota full-size wind tunnel, Shanghai Tongji pneumatic Chinese domestic construction / acoustic wind tunnel.
A is Sge; 30 square meters tunnel. Such is mainly used for wind tunnel tests to intermediate sedan truck and bus. Such as GM full-size wind tunnel, aerodynamic center in China 8mtimes; 6m wind tunnel.
Cars wind tunnel – Composition
by a tunnel main body hole, the drive control system and measurement system, in the form of each part by tunnel type.
Cars wind tunnel – Characteristics
ldquo; car tunnel rdquo; enormous artificial wind, air resistance can simulate various driving environments encountered noise , thermodynamic state, weather conditions and even solar radiation for safety and handling stability testing prototypes, to minimize power loss in the running car, the design is more energy-efficient, providing beautiful car conditions.
automotive wind tunnel – testing laboratories
ldquo; automotive wind tunnel rdquo; the very beginning in fact not used to test the car, but used to test aircraft, research aerodynamic performance of the aircraft. Experiment, the model or the kind normally secured within the tunnel, the gas flow through the model. In this way, the flow conditions are easy to control, reproducibly, economically obtain experimental data. For accurate results, when the flow experiment must be similar to the actual flow condition, i.e., must meet similar law. But due to the size and power of the wind tunnel, and simulate all similar parameters in a wind tunnel is very difficult, usually according to the subject to be studied, selected some of the largest impact parameter simulation.
In addition, the quality of the flow field of wind tunnel test section, such as the gas flow velocity distribution, average size of the gas flow direction offset from the axis of the tunnel, along the axial direction of the wind tunnel pressure gradient, temperature distribution uniformity of cross section, airflow turbulence and noise levels must meet certain criteria, and is checked regularly measured. Car speeds up to 110 km when the wind resistance to 70 percent of total resistance, most of the fuel used to overcome the drag, wind tunnel tests and therefore, in the case of simulated vehicle is traveling, shape optimization automotive design to reduce windage , save fuel and reduce noise, which is the main purpose automobile wind tunnel tests. Edit this paragraph car wind tunnel – in China after years of construction, the first domestic automobile wind tunnel mdash 2009 Nian 9 Yue 19 Ri; mdash; Shanghai Wind Tunnel Center was officially inaugurated at Tongji University!
wind tunnel: milestone in the development of China’s auto industry
China’s first ldquo; automotive wind tunnel rdquo; at Tongji University inaugurated
September 19, 2009, to spend 490 million yuan to build China’s first domestic ldquo; automotive wind tunnel rdquo; mdash; mdash; Shanghai Wind tunnel Center at Tongji Jiading campus was officially opened, to fill the domestic automotive R & D design more Chinese blank.
Wind Tunnel Center project consists of the construction of Tongji University, a total investment of 490 million yuan, and Shanghai is a major industrial and technology research projects. Shanghai Wind Tunnel including the first domestic car aeroacoustics vehicle wind tunnel, the country’s first automobile wind tunnel thermal environment and a set of car styling, processing, equipment maintenance, research and management in one of the multi-purpose center. It is with Shanghai International Automobile City Jiading completion of the initial construction of new energy Automotive Engineering Center, Tongji University, Shanghai Automotive quality inspection centers, automobile proving ground together to form a world-class, fully furnished ground vehicle testing research base. Is regarded as a breakthrough independent research and development bottlenecks Shanghai Wind Tunnel Center, consists of two wind tunnels: one is the first domestic car aeroacoustics vehicle wind tunnel, and the other is the thermal environment of the vehicle’s first wind tunnel. Function varied: for a wind, the measured resistance measurement noise; the other is used to measure temperature, the measured environment.
It is reported that, as a key technology platform public rail cars and vehicles, ldquo; automotive wind tunnel rdquo; for the Chinese automotive industry and rail vehicles, in particular, provide an important foundation for the independent research and development of new energy vehicles services for China’s auto industry from ldquo; rdquo Chinese manufacturing; towards ldquo; China to create rdquo ;, to create the necessary conditions.
the wind tunnel of the key technical indicators have reached the world advanced level, and with full independent intellectual property rights. In addition to supporting the auto companies, the newly opened Shanghai Wind Tunnel Center will also provide independent research and development and high-speed trains China’s large aircraft project, providing the indispensable key technical support platform.