The Optimization of an Integrated Strut OGV Configuration

Abstract

In a core-mounted high-bypass ratio aero engine the bypass strut is designed to support the intermediate casing and to go the RDF (radial drive shaft) of a large diameter. Therefore the maximum thickness of the strut and maximum thickness distribution along the chord are restricted by the maximum diameter of the RDF. In order to enhance the total pressure recovery coefficient as well as reducing the backpressure circumferential variation, in this paper we describe the optimization of a datum configuration of the circumferential integrated strut OGV (Outlet Guide Vane). The datum configuration was designed based on an original configuration in which OGV and struts are separated axially. In the datum configuration, OGV is moved down-stream to be combined with the struts. The combined strut not only supports the casing as discussed above but also plays the role of turning the flow from the upstream fan to the axial direction. At the same time, the maximum thickness of the strut is about 8 times thicker than that of the OGV. The datum configuration will reduce noise because of larger axial distance between fan and OGVs as well as reducing weight because of fewer struts used in datum configuration. A re-staggering of OGV with sweep and dihedral both at the tip and hub will be used to optimize this datum configuration. Both datum configuration and optimized configuration will be compared with respected to the pressure loss included in the OGV and struts and the backpressure circumferential distribution variation.