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Flow oscillations in a duct with a rectangular cross-section

Published online by Cambridge University Press:  11 April 2006

J. S. Anderson
Affiliation:
Max-Planck-Institut für Strömungsforschung, Germany Present address: Department of Mechanical Engineering, The City University, London.
W. M. Jungowski
Affiliation:
Max-Planck-Institut für Strömungsforschung, Germany Present address: Warsaw Technical University.
W. J. Hiller
Affiliation:
Max-Planck-Institut für Strömungsforschung, Germany
G. E. A. Meier
Affiliation:
Max-Planck-Institut für Strömungsforschung, Germany

Abstract

A two-dimensional configuration has been investigated in which air flows through a convergent nozzle and expands abruptly into a rectangular duct of larger cross-section which terminates in a plenum chamber. Three different types of oscillation have been observed in the downstream duct. At low plenumchamber pressures an oscillation occurs towards the exit of the duct as the boundary layer of the flow becomes alternately separated and attached. At increasing plenum pressure a shock-pattern oscillation takes place in which a change from a normal shock to oblique shocks occurs during a cycle. At still greater plenum pressures a base-pressure oscillation occurs which influences the entire duct flow downstream of the abrupt change in cross-section. The amplitudes of the oscillation can be as high as 10% of the rest state, and the frequency of the base-pressure oscillations can be predicted approximately from one-dimensional gasdynamic theory.

The unsteady duct phenomena have been studied by synchronizing instantaneous pressures measured by quartz pressure transducers with interferograms obtained with a Mach–Zehnder interferometer.

Type
Research Article
Copyright
© 1977 Cambridge University Press

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References

Anderson, J. S. 1972 The noise from abruptly expanded jets. EUROMECH 34, Colloq. Control Feedback Mechanisms in Flow Noise, Göttingen.Google Scholar
Anderson, J. S. & Williams, T. J. 1968 Base pressure and noise produced by the abrupt expansion of air in a cylindrical duct. J. Mech. Engng Sci. 10, 262268.Google Scholar
Bogdonoff, S. M. & Vas, J. E. 1959 Preliminary investigations of spiked bodies at hypersonic speeds. J. Aero. Space Sci. 26, 6574.Google Scholar
Dailey, C. L. 1955 Supersonic diffuser instability. J. Aero. Sci. 22, 733749.Google Scholar
Dvorak, R. 1964 On the unsteady boundary-layer shock wave interaction in the lower transonic region. Arch. Mech. Stosowanej, 16, 211222.Google Scholar
Ginzburg, I. P., Semiletenko, B. G., Terpiggorieff, W. S. & Uskoff, W. N. 1970 Some pecularities resulting from the interaction of a supersonic under-expanded jet with a flat plate. J. Engng Phys. 19, 412417 (in Russian).Google Scholar
Holden, M. S. 1966 Experimental studies of separated flows at hypersonic speeds. Part 1: separated flows over axi-symmetric spiked bodies. A.I.A.A. J. 4, 591599.Google Scholar
Jungowski, W. M. 1967 On the pressure oscillating in a sudden enlargement of a duct section. Fluid Dyn. Trans. 1, 735741.Google Scholar
Jungowski, W. M. 1968 Investigation of flow pattern, boundary conditions and oscillation mechanism in a compressible flow through sudden enlargement of a duct. Warsaw Tech. Univ. Publ. no. 3.
Jungowski, W. M. 1969 On the flow in a sudden enlargement of a duct. Fluid Dyn. Trans. 4, 231241.Google Scholar
Karashima, K. 1961 Instability of shock wave on thin airfoil in high subsonic flow. Aero. Res. Inst., Univ. Tokyo, Rep. no. 363.Google Scholar
Maull, D. J. 1960 Hypersonic flow over axially symmetric spiked bodies. J. Fluid Mech. 8, 584592.Google Scholar
Meier, G. E. A. 1974 Ein instationäres Verhalten transsonischer Strömungen. Mitt. Max-Planck-Inst. Strömungsforsch. Aero. Versuchsanstalt, no. 59.Google Scholar
Meier, G. E. A. 1975 Shock-induced flow oscillations. AGARD Current Paper, no. 168, pp. 30-1–30-9.
Meier, G. E. A. 1976 Shock-induced flow oscillations in a Laval nozzle. Proc. IUTAM Symp. Transonicum II.
Meier, G. E. A. & Hiller, W. 1968 An experimental investigation of unsteady transonic flow by high-speed interferometric photography. AGARD Current Paper, no. 35.
M ø rch, K. A. 1964 A theory for the mode of operation of the Hartmann air jet generator. J. Fluid Mech. 20, 141159.Google Scholar
Naumann, A. 1965 StosZschwingungen an Profilen. Abh. Aero. Inst., TH Aachen, 18, 913.Google Scholar
Trilling, L. 1958 Oscillating shock boundary-layer interaction. J. Aero. Sci. 25, 301304.Google Scholar
Witczak, K. J. 1975 Noise caused by sonic flow of gas into a duct. Doctoral thesis, Warsaw Technical University.