Title of article
Experimental investigation into the effects of Mach number and boundary-layer bleed on flow stability of a supersonic air intake
Author/Authors
Sepahi-Younsi, Javad Mechanical Engineering Department - Faculty of Engineering - Ferdowsi University of Mashhad - Mashhad - Iran , Soltani, Mohammad Reza Department of Aerospace Engineering - Sharif University of Technology - Tehran - Iran , Abedi, Mahdi Department of Aerospace Engineering - Sharif University of Technology - Tehran - Iran , Masdari, Mehran Faculty of New Science and Technologies - University of Tehran - Tehran - Iran
Pages
9
From page
1197
To page
1205
Abstract
A series of experiments were conducted to study impacts of the free stream Mach number, back pressure and bleed on the stability of a supersonic intake. The flow stability is related to the buzz phenomenon; oscillation of all shock waves of the intake and it may further occur during the time when the intake mass flow rate is decreasing. The present intake is an axisymmetric intake for Mach number of 2.0. The results showed that the stability margin of the intake decreases when the freestream Mach number increases for both bleed off and bleed on cases. For the configuration without bleed, the frequency of buzz oscillation is increased when the freestream Mach number is decreased or when the back pressure is increased. By applying the bleed and consequently preventing the flow separation, the intake is more stable and the shocks oscillate with a smaller amplitude during the buzz phenomenon. When the bleed is applied, the buzz triggering mechanism varied from the Dailey criterion to that of the Ferri one, a phenomenon that changes the stability characteristics of the intake considerably.
Keywords
Supersonic Air Intake , Buzz Phenomenon , Mach number , Boundary Layer Bleed , Oscillation Frequency , Bleed Exit Area
Journal title
Scientia Iranica(Transactions B:Mechanical Engineering)
Serial Year
2020
Record number
2555266
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