侧风条件下进气道流场及地面吸入涡特征研究

采用数值模拟与试验方法对大涵道比发动机进气道缩比模型在地面侧风工况下的流场特性进行了研究分析，同时考虑了侧风与地面吸入涡对进气道流场的影响，以及侧风对吸入涡强度的影响，在此基础上解释并分析了侧风对进气道流场的双重影响作用。研究结果发现:根据吸入涡在侧风影响下的生成特性，以及吸入涡和侧风因素对进气道流场作用程度的不同，吸入涡从稳定状态到被侧风吹除的过程中存在三个阶段，吹除起始阶段、迅速吹除阶段和吹除完成阶段，并且发动机进气道吸入速度越大，对应这一过程的起始吹除速度和完全吹除速度越大，但相应的速度比基本不变；在吸入涡被完全吹除之前，侧风通过对吸入涡强度的影响对进气道流场产生双重作用，在吹除起始阶段和吹除完成阶段，侧风的影响对进气道流场起主导作用，与无地面工况类似，进气畸变随着侧风速度的增大而增大，在迅速吹除阶段，吸入涡的影响对进气道流场起主导作用，进气畸变随着侧风速度的增大而减小。 

Research on the inlet flow field and ground vortex under crosswind condition

The aerodynamic performance of a scaled model of high bypass ratio engine inlet under the ground crosswind condition was studied by combining the numerical simulation and experiments, considering the influence of crosswind and ground suction vortex on the inlet flow field and the effect of crosswind on the ground vortex strength; then the double function of the crosswind on the inlet flow field was explained and analyzed. The results indicated that: according to the generation feature of ground vortex and the influence level of crosswind and ground vortex acted on inlet flow field separately, the process from steady state of ground vortex to being blown off can be divided into three stages, i.e.: the initial stage, the rapid stage and the end stage. With the increase of engine inhalation velocity，the initial blow-off speed and the complete blow-off speed increased, but the corresponding velocity ratio basically kept unchanged; before the ground vortex was blown away completely, the crosswind maked double influence on the inlet flow field by affecting the suction vortex, in the initial stage and the end stage, the influence of crosswind played a leading role in the inlet flow field, similar to no-ground condition, the inlet distortion increased with crosswind in this two stages, in the rapid stage, the influence of ground suction vortex played a leading role in the inlet flow field, the inlet distortion decreased with crosswind.