Investigation on coanda gap variable-camber inlet guide vanes for core driven fan stage

摘要

As a key part of the core driven fan stage (CDFS), variable-camber inlet guide vanes (VIGVs) must be stably and efficiently operated at two different operation modes including the single bypass mode and the double bypass mode. The design method was presented to generate the VIGVs with wide operating range of flow turning angles under the requirement of low loss in order to satisfy the needs of CDFS. The results of numerical simulation and experiment test showed that the use of Coanda type surface to design the slotted shape can effectively enhance the wall attachment performance of the leakage flow and suppress the development of the suction surface boundary layer behind the slotted position. Moreover, the Coanda type surface can reduce more than a half of total pressure loss than the conventional circle shape at the large flow turning angles. The VIGVs are in good agreement with the designing requirements of CDFS at the single and double bypass modes validated by the cascade experiment and three-dimensional simulation of CDFS.