期刊名称：Eastern-European Journal of Enterprise Technologies
印刷版ISSN：1729-3774
电子版ISSN：1729-4061
出版年度：2018
卷号：6
期号：8
页码：65-73
DOI：10.15587/1729-4061.2018.147986
语种：English
出版社：PC Technology Center
摘要：We have conducted an experimental study into aerodynamic characteristics of the structural scheme “wing ‒ twocircuit engine nacelle”. The data were acquired in the course of work of a promising system for the neutralization of a twocircuit engine’s thrust of a large bypass ratio at aircraft landing. The relevance of the conducted study relates to the improvement of operational performance of a passenger aircraft. Based on the analysis of functions and principal schemes of reversible devices at cargo and passenger airplanes, we have proposed a promising method to neutralize the thrust of a twocircuit engine with a high bypass ratio. Physical essence of the method for neutralization of the engine’s thrust is to substantially restrict an airflow into the engine by a technique to rotate working blades of the fan at the time of landing. We have devised a specialized procedure for conducting a weighting and drainage experiment with a model of the nacelle of a turbojet twocircuit engine in a wind tunnel. The obtained experimental data make it possible to evaluate the limits of the investigated method for neutralizing the thrust in order to shorten the length of aircraft run. By conducting a drainage experiment and applying a tuft flow visualization technique, we identified the detachment of a flow at the outer surface of the nacelle’s model with a completely closed entrance. The presence of the flow detachment predetermined an increase in the frontal drag of the nacelle model by approximately 2.5 times, revealed by the weight experiment. In the course of the weight experiment it was established that the existence of a screening surface (while the engine’s nacelle approaches a runway) increases frontal drag of the nacelle model by approximately 14 %. The drainage experiment found that such an increase in the frontal drag was due to a significant redistribution of pressure at the surface of the nacelle model. The study has shown that the idea of closing the entrance to the engine that has a large bypass ratio at the time of aircraft landing is one of the promising methods for shortening the run length of the aircraft
