公开(公告)号：US5431533A

公开(公告)日：1995-07-11

申请号：US138582

申请日：1993-10-15

Applicant: David E. Hobbs

Inventor： David E. Hobbs

IPC: F01D5/14 ,  F01D11/08 ,  F04D19/02 ,  F04D27/02 ,  F04D29/54 ,  F01D1/12

CPC classification number: F01D11/08 ,  F01D5/145 ,  F04D27/0215 ,  F04D29/526 ,  F04D29/685 ,  F05D2220/327 ,  F05D2270/101 ,  F05D2270/1022 ,  Y02T50/671 ,  Y02T50/673

Abstract: The recirculating flow in the vaned passage in the case surrounding the tips of the fan blades of a turbo fan engine or ducted fan propulsor is modified or blocked off during certain engine or aircraft operating modes. In one embodiment an aneroid valve closes off the vaned passage upon attaining a given altitude and fails open to assure that the safe stall margin is retained during take off. The active VPCT serves to increase fan efficiency and engine thrust while maintaining stall margin at the required safety level. The vaned passage in another embodiment is utilized to abate or preclude the stall precursor waves manifested by the rotor blade by modulating the recirculating flow as a function of time.

Abstract translation: 在涡轮风扇发动机或导风扇推进器的风扇叶片的末端周围的壳体中的通风道中的再循环流在某些发动机或飞行器操作模式期间被修改或阻挡。 在一个实施例中，空气阀在达到给定高度时关闭了通风道，并且不能打开以确保在起飞期间保持安全失速余量。 有源VPCT用于提高风扇效率和发动机推力，同时将失速裕度保持在所需的安全水平。 另一个实施例中的通风道用于通过调节循环流作为时间的函数来消除或排除由转子叶片表现的失速前兆波。