Abstract
Shock trains in rectangular isolators with inflow Mach number of 2.5 and ARs of 3.0 and 6.0 are investigated. Knowledge gained is used to propose a rectangular isolator modification to existing empirical shock train length relations based on circular ducts. A novel, multiplane shadowgraph concept allows simultaneous flow visualization from multiple perspectives. Boundary-layer separation in the low-momentum corner flow regions is observed to occur upstream of the center-flow field by approximately one duct height. The leading edge shock train structure is composed of a hybrid oblique–normal shock front, with oblique shocks spawning from the corner flow separation transforming into a normal shock front near the centerline. Dynamic wall pressure measurements made along the duct major axis allow for direct comparison between the outboard and centerline sensor’s ability to detect incipient unstart, with the outboard sensor detecting the separation-induced pressure rise well ahead of centerline measurements. A modified shock train length relation for rectangular isolators accounts for the effects of potential boundary-layer momentum thickness asymmetry, upstream corner flow separation length scale, and AR magnitude. Improvements in correlation strength are discussed for both ARs, with coefficient of determination and root mean square error improvements on the order of 60% observed for the highest AR tested.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
