The J-10 crash: Russia on engine fatal defect too, but refused to improve
fenghuangjunshi· 2017-12-17 13:45:35
" in the J-10 has identified the cause of the accident crash accident, no one is caused by the FBW; in addition to a handful of human reason Illusion -- such as flying in the sky, not the ground outside the case, almost all from the engine fault. The
engine reliability problems due to the J-10 accidents, there are two aspects of the innate and acquired factors. From a congenital point of view, the single engine itself is more dependent on the reliability of the engine, but the engine is more prone to problems on the single engine. However, the Russian AL-31 series is not a reliable engine in terms of Western product standards." from the Navy public papers from
acquired factors, improvement in the reliability of AL-31F series engine, domestic and Chinese unable to do, Russia to take a pair of no money, no money, come up with many achievements see mood attitude. Is the AL-31F engine J-10 equipment reliability to improve the long term key. The reliability of the
AL-31 engine has a serious defect, that is, the lubrication and cooling system of the engine spindle is not very reliable, and it is in love with failure.
can reach more than 10000 rpm for maximum speed of engine parts under high temperature, once the loss of spindle lubrication; the bearings will be facing a sharp increase in the temperature, after partial melting welding repeated internal friction surface and tear phenomenon. This process of continuous welding, tear, will cause the bearing friction surface becomes uneven, the friction force increased sharply, rotating instability, finally directly stuck. Once the engine holds the shaft, the natural power is completely lost.
in the Chengdu J-10 engine wreckage crashed this problem is not unique to AL-31F, but the research of aeroengine, a key technical difficulties itself can not be avoided. The higher the working temperature of the engine, the higher the speed of the engine and the more complex the design of the structure, the more difficult the lubrication system will be to design. The performance of American early engine is not very good in this respect; in the reliability problem of China's Taihang engine, lubrication is also a key link. The
AL31F engine is limited to the Soviet era limited level, low efficiency framework, using very complex structure was obtained and high thrust and high maneuver flight can still work effectively. The dual medium bearing and four bearing low pressure rotor design resulted in the AL31F lubrication system being forced to do very complex -- and the Soviet Union's level in this regard is very poor. Finally, the poor reliability is the inevitable outcome. Since the introduction of
from the Soviet Union 27 series, the failure of the lubrication system has led to the reduction of engine speed (protective action, delayed arrival of parking), reduction of thrust and even air parking accidents." because Su 27 is a twin engine fighter, another engine load share so AL31F fault, progress to complete loss of thrust is relatively slow, even a complete loss of thrust, still have a high probability of landing by single. In the J-10, fatal degree of this problem is greatly increased. It is impossible for
to run into such a problem. It is impossible for us to remain untouched at home. Since 90s, we have been in contact with the relevant departments of Russia, and have asked Russia to give effective and effective improvement measures. But Russia has always said that there has been a study and exploration of the design in this respect; but there is no money to do the experiment, and it can not give a solution to the principles.
at the end of the day, Russia is in the opportunity to blackmail China. Because this lubrication reliability problem is the key bottleneck that limits the whole AL31F family to increase, especially increase the high speed thrust. The reliability is not improved. The more the increase and the higher the engine working temperature, the only outcome is the faster death.117S", Russia refused to be installed in the F - 20
117S and 30 products from the later engine situation -- including turbine inlet temperature, thrust and life index increased greatly; in the lubrication system, must be realized a very large degree of improvement. However, these two products to Russia Chinese are restricted or banned, 20 fighters originally planned to use the Russian 117S engine, but now only allowed the Russian Soviet 35 equipment China the engine.