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CSR Qingdao Sifang Locomotive Co., Ltd. plant in the region , a silver speed test train parked on the factory rails , bench this column reaches 605 kilometers per hour speed of the train , the train is named test higher speed .
In fact, as early as the trial began more than two years ago, for this test , CSR Sifang company after seven program discussions.
Participate in the trial of Minister of Development, Jiao Jinghai Electric recently recalled: . " That are not worried about 100-200 kilometers , 550 kilometers above the speed on the mood began to stir , to 600 km when it started a little nervous ," test stop at 605 km , because the test targets developed for 600 kilometers , " the test station building is designed by 600 kilometers , and then further on the red speed , fear of bad test bed " , senior Director Bing designer explains .
Speed was raised to 605 km when the test did not immediately stop , keep the speed to run for 10 minutes , which is equivalent to the ground with a 100.8 km .
Higher than the aircraft technical difficulty
" High-speed rail as an aircraft taking off and landing constantly ," Chinese Academy of Mechanics Yang Guowei researcher said. Yang Guowei creation of nonlinear aeroelastic transonic research , aerodynamic and aeroelastic provide technical support for China's high-speed rail and large aircraft development .
" The most dangerous is the plane taking off and landing , because the ground effect , including construction , wind Excitation on the aircraft , so the difficulty in aircraft design and descending from the process , while the high-speed trains always run at high speed on the ground, from the air force learn to drive each other 's role and air angle , it is necessary to consider the face of strong excitation of the train , but also taking into account the situation of the airflow at high speed laser interference. Boeing 737 cruising the drag coefficient is about 0.028 , 6 train marshalling test vehicle drag coefficient is about 0.48 , so that the technical difficulties of higher speed trains than planes in the sky when the cruise is much more complicated . " Yang Guowei said.
Civilian aircraft flying from 800-850 km per hour , China developed more speed test train design speed of 500 kilometers per hour or more, compared with the current on -line running to a top speed of 380 kilometers per hour CRH380A, technology must clear the boundary conditions .
" Aerodynamics track irregularity affected by vibration Excitation response continues to increase, how to ensure the safety of high speed trains ; how to ensure comfortable traveling environment ; more important than speed to be able to raise a good stop . " test scene commander Liang Jianying said.
Train running resistance including friction wheel and rail vehicles mechanical resistance and air resistance . Restrict the speed to compete at high speed by air, "When the train to about 70% when traveling 200 kilometers per hour , the total resistance of air resistance , Harmony CRH380A speed Beijing-Shanghai high-speed railway ran 486.1 km , aerodynamic drag than 92% of the total resistance , if it went to 500 km or more, more than 95 % of all the aerodynamic drag , " Bing said. Air resistance and the train speed is approximately proportional to the square of the speed increased by 2 times , the air resistance will be increased to four times . It is this square relationship , so designers brains .
Air resistance affected by three factors , namely the front windward under positive pressure, pressure resistance between the rear generated by the negative pressure ; Second, due to the viscous effects of air friction on the body surface ; Third train chassis and an interference caused by the resistance of the train uneven surface structure .
Engineers to reduce air resistance , the application of bionics and aerodynamics theory , created more than 100 kinds of head -of-concept , it is preferable to build more than 80 kinds of three-dimensional digital models , to carry out a preliminary simulation of aerodynamics , aerodynamic performance than to elect 20 optimum head type, further aerodynamic optimization , to produce physical models 1:20 , according to the simulation data, and aesthetic effect , ultimately making five head type 1:8 mechanical tests were done in a wind tunnel and aerodynamic noise test , called " arrow " head type is selected, its aerodynamic noise , aerodynamic drag of the optimal parameters . "From the aerodynamic performance is concerned, ' Arrow ' and the airliner is the PK ." Bing said.
Make hundreds of tons of high-speed trains on the line more gallop , in addition to reducing aerodynamic drag , the increased towing capacity is another key . " Six -speed test train marshalling more traction total power up to 21,120 kilowatts . Precisely because of our self-developed high-power traction system , only to realize the high-speed test train bench 605 km / h possible ." Jiaojing Hai said.
Technology research and development of high-power traction drive system , with a strong technology diffusion effects , in addition to the train can be applied in other manufacturing areas . " High-power traction drive system technology has good epitaxial nature , in addition to rail transport sector , traction drive power transmission in many areas have a very wide range of industrial applications, such as rolling system , ship propulsion systems, oil drilling, power systems, etc. . " Director CSR Times Electric technology Center荣智林said.
Rely on electricity to run high-speed trains , is a catenary pantograph in contact with the completion of this process is called " subject to flow" link. This technology is so far one of the most technical technical experts concerned . "Double bow by streaming " technology used to be a technical difficulties plagued engineering and technical personnel , " it now appears that it does not look like technical difficulties ," and Liang Jianying said. " When the vehicle is running at high speed , the bow in the front to take power over the catenary, will form a shock wave interference , leading to the possibility of the bow off the increase, affecting the performance of the vehicle traction after how to ensure the stability of the stream by the bow this is a technical difficulty , but now it seems , no longer exists . "
The pursuit of faster
Speed is the overall strength of the technology development. Like China " bombs and one satellite " of development, give the country , ten thousand scientific and technical personnel involved in the high-speed train technology innovation . " Test the speed of the train is only laboratory data , the actual line data needs to be further verified , we want to have a high rate of value , so that the whole world can learn more about China 's high-speed rail technology and product level , where the process need to get down to do it , and must not be so anxious . " Liang Jianying said.
" Speed of 605 km was test rig ran out , not the line of the data , the actual line test also requires a series of assessment ." Bing said. April 3, 2007 , the French TGV line on the road to create a 574.8 km / h maximum speed test , so far there has not been a new record refresh. December 2010 test pilot section of Beijing-Shanghai Bengbu - Zaozhuang , CRH380A reach a top speed of 486.1 km , although this rate is the operational test speed , it is different from a pure test of speed TGV in France . On the operating speed of the test in terms of value it is the highest in the world.
2011 , " 7.23 " Yongwen line especially after a major railway accident , Chinese high-speed rail began a quest for higher quality objectives , including safety, reliability , comfort and so on. In fact the quality is not due to the car accident , but the accident but then the development of China 's high-speed rail has brought great impact. All railways , including CSR Sifang technicians in reflection, that is, how to make better , more robust to advance the cause of the country 's high-speed rail . Development and testing of the train is a very laborious process. It EMU CRH380A new generation of technological innovations , based on principles of safety and reliable operation of the target , for system integration, body, bogie , traction, network control, the braking system has been a lot of technological innovation to achieve a carbon fiber material, magnesium aluminum range of new technologies , nanomaterials, drag brake system, loading tests verify the new material. After the development of the whole train of more than two years time .
After completion of the test train laboratory tests in the factory area of a 3.7 km loop test line for a month reliability test , running mileage of about 1000 km . Subject line conditions limit the maximum speed does not exceed 30 kilometers per hour , " on the vehicle , system and component reliability verification completed an initial " engineer told reporters .
A number of new technologies to be verified
High-speed rail , one of China's strategic emerging industries , and more high-speed train is another sign of China's innovation capabilities of the works . Engineers and scientists eager to test on-line verification test bench convergence results , more in-depth exploration of ultra- high-speed train three core technologies theory that the wheel-rail technology , aerodynamics and bow gateway system .
For engineers , the design is not complete and many items in the bench , the more high-speed trains have two three core technologies can not verify that the aerodynamic performance and bow gateway system .
For example, the bench in the room is complete, the lack of wind, you can not complete the aerodynamic tests. " More high-speed trains are the primary resistance characteristics to verify the car involves energy consumption ; followed by the lift characteristics , related to the derailment coefficient ; third is the size of the pulse power , related to the safety of the train there is the intersection of the instantaneous wind . resistance , avoidance and safe distance . Theoretically , there are formulas for 400 km and 500 km of the car should be applicable on the study and confirmed , these are the need for further verification through on-line test . " Yang Guowei said. In addition , even if the two-way rolling test bed, can not be completed by the flow test pantograph and catenary .
To do basic research scientists , they want to verify the basic theory of the mechanism of common key technologies. In derailment coefficient , for example, the vehicle is running, the line conditions , under use conditions , vehicle loading and other factors structural parameters and the most unfavorable combination of conditions could lead to derailment , measures to prevent derailment derailment coefficient called the stability index , the more this factor large more easily derailed.
According to international standards, 0.8 as a derailment safety indicators. " But we found when testing high-speed train , the train line to 480 km speed derailment coefficient of only 0.1 to 0.2 or so, far less than 0.8 , if the speed of 550 kilometers per hour , the actual running time of the derailment coefficient is the number ? it involves the study of basic mechanics of speed . scientists worldwide have been hoping to crack the mystery of the derailment coefficient . " bogie engineer Ma Lijun said.
Promote the development of the industry
This century is the era of high-speed rail . U.S. President Barack Obama in the 2011 State of the Union , said , "There is no reason to Europe and China has the fastest railway ," Obama strongly aware that high-speed rail will reshape the global competitiveness of U.S. technology high ground. " Technically it must be to seize the high ground , who has the ability to seize the commanding heights of technology , who have the capacity to promote the development of the industry . Demand advanced technology -driven market, which is the law of competition in the global market economy ." Said Liang Jianying .
2007 French TGV to create " the world's first speed" to counter the German maglev seize market challenges. " France is precisely because the road ran over 570 kilometers , a clear signal to the world , my technique is feasible. Since then, France became the world's market leader in high-speed rail ." Yang Guowei said. China high-speed rail is speed the pace towards the world , indicating that the trend is still high speed . Explore more than 500 kilometers of ultra- high-speed train technology , is both a prospective study , but also to expand the international market technical reserves.
Accumulation of mature technology needs , while expanding the market is the extension of the moment . China high-speed rail since 2004 , after nine years, from the introduction , digestion and absorption into the now fully -leading technology , the development of more high-speed test train is the commanding heights of technology vertical development, and only master the technical high ground, to be able to make the technology vertical mutual transfer and horizontal, covering market size increments. "This test train which is based in CRH380A technology to expand upward , while intercity trains is downward expansion. HSR so many years of technology innovation, its technological advancement has passed upstream and downstream products ." Liang Jianying said.
Pursuit of technology did not stop . To better understand the role of the relationship between aerodynamics , CSR Sifang company is planning to build a small-scale wind tunnel laboratory . "Although we are an engineering unit , but we need to break his own master and accumulation of new technologies and want to leave something for the future ." Liang Jianying told reporters.
For more high-speed train line verification test , the state parties to give full attention to work on-line test train is already in full swing, the technical performance of the train line will be further validated in experiments . The whole process will be implemented in phases , will be a step by step to get a variety of technical parameters. "We hope it has a very good performance , let the world know more about China high- speed rail technology ." Engineers say .
