China’s large and medium aircraft flutter flight test techniques were a major breakthrough (Figure)
Data Figure: China’s large passenger aircraft developed by the C919 model
CPPCC, China Aviation Industry Corporation deputy chief engineer of Sun Chung told reporters recently in the Shaanxi Institute of flight in the aircraft industry came the good news, as outside the safety of an aircraft landing field, for many years and medium-sized aircraft flutter flight test of scientific research work on the painting satisfactory conclusion. This marks the aircraft industry in the medium-sized aircraft with independent intellectual property rights of inertial flight flutter excitation system is technically a major breakthrough, as the United States, Russia and other developed countries can carry out independent aviation aircraft flutter flight test and medium-sized countries.
in the world aviation industry, flutter, spin and air parking stall is recognized as “the three Class I risk” test subjects. From the perspective of aircraft development and flight testing, aircraft flutter is the biggest challenge, because the aircraft flutter occurs once in the air, dissolution in a few seconds, the pilot little time to dispose of, very small probability of escape. As the great flutter flight risk, so test before strict safeguards. AVIC flight flutter testing hospital after years of research and development, has formed a strict security measures and reasonable and effective monitoring of the flight control system for the associated flight test has laid a good foundation.
for flutter flight, the aircraft to install incentive systems to encourage a dangerous state of flutter all structural vibration mode, so choose an effective method of flutter excitation becomes subject breakthrough key. Comprehensive hospital in the aviation industry flight flutter testing of existing domestic and international incentive methods, after a lot of testing and data analysis, a major breakthrough, the successful retrofit of the world’s advanced level of medium-sized aircraft, new inertial actuator system, and for the first time independently developed the inertial actuator, combined with the method of pulse excitation control surface flutter testing air flight, the aircraft effectively solve the problems of medium-sized technology incentive problems. Outside the field test, the flight crew completed the final phase of the project large high-altitude flight test condition of Mach. Through data analysis, the flutter characteristics of aircraft fully up to standard, proven ways to motivate and test method.
Chatter is the vibration of the aircraft structure, the most dangerous form, it is aerodynamic, elastic resilience and inertia of the three coupling vibration under the action of a form, is more aircraft flying in an accident and often disastrous consequences of a aeroelastic phenomenon. According to statistics, for decades, the world flutter caused by major accidents have occurred. Risk subjects in Class I, flutter is the only can not be artificially controlled conditions (air, parking stall and can be changed by the manipulation of the pilot out and restart), only through the proper design to prevent. Therefore, developed countries in the early stages of the new machine will begin to prevent flutter studies that runs through the whole process of development of new aircraft. Typically, to prevent flutter flutter studies include theoretical calculations, scale model of high-speed wind tunnel experiments, all machine ground resonance test and aircraft flutter flight testing. Aircraft flutter flight test in the ultimate anti-flutter research areas, it uses real aircraft under actual flight conditions tested, with a variety of simplifying assumptions that are not unique advantages. Thus, aircraft flutter flight test as validation of new machines (including major variant of the aircraft) essential to the security flutter, the most convincing key.