Abstract

Experiments are carried out to characterize the un-start/re-start phenomena in an isolator with steady and low-frequency oscillatory back pressures (0.75 Hz–2.5 Hz) in Mach 1.7 flow. In the present study, the effect of shock train interaction with the intake shocks is focused to capture these phenomena. It is demonstrated that the un-start mechanism is a continuous process with steady back pressures, whereas it is a discontinuous process under oscillatory back pressures. The un-start mechanism is triggered once the oscillatory back pressure is above the maximum isolator pressure. As the frequency of back pressure oscillation is increased, the isolator experiences an early un-start and a delayed re-start. On the other hand, if the oscillatory back pressure is decreased, the re-start process is initiated. During the re-start process, the time lag is found to be increased, and the hysteresis loss is decreased with an increase in oscillatory frequencies. These phenomena are studied through both the steady and unsteady pressure measurements along with instantaneous schlieren images for different dynamic pressures. Furthermore, the un-start can be avoided or delayed by increasing the freestream dynamic pressure.

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 call

Disclaimer: 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.