Numerical simulation of shock wave patterns in supersonic divergent symmetric nozzles

• Autorzy: Namieśnik K. , Doerffer P.
• Języki publikacji: EN

Abstrakty

EN

This paper presents the results of numerical simulations of supersonic flows with shock waves in a divergent symmetric nozzle of an opening angle ranging from 2 degrees to 6 degrees. At certain Mach number values the shock pattern becomes asymmetric. This asymmetry is analysed here for different values of velocity upstream of the shock wave and for different nozzle divergence angles. Only the divergent part of the nozzle is considered. Supersonic conditions at the nozzle inlet were prescribed with a chosen Mach number value Ma>1. The inlet velocity profile included a turbulent boundary layer profile on side walls. The steady flow simulation was applied for nozzle opening angles, α , of 1.877 degrees, 2.5 degrees and 3 degrees, whereas the unsteady approach was necessary for a nozzle of the divergence angle α =6.54 degrees to obtain a converged solution. The asymmetry of the shock structure is visible in the unevenness of the heights of both λ-feet. It happens at the same Mach number, at the same boundary layer and with the same geometrical constraints. This is in contradiction with our current understanding of the parameters affecting λ-foot size. The paper provides an explanation of this problem.

Słowa kluczowe

EN

supersonic flows; supersonic nozzle; shock waves

• Wydawca: Politechnika Gdańska
• Czasopismo: TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
• Rocznik: 2005
• Tom: Vol. 9, No 1
• Strony: 53--63
• Opis fizyczny: Bibliogr. 6 poz., rys.

Twórcy

autor

Namieśnik K.

• Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk, Poland

autor

Doerffer P.

• Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk, Poland

Bibliografia

• [1] Szwaba R 2001 Introductory Measurements in a Nozzle for High Mach Numbers, IMPPAN 1236/2001 (in Polish)
• [2] Magagnato F 1998 TASK Quart. 2 (2) 215
• [3] Ackeret J, Feldman F and Rott H 1946 Untrrsuchungen an Verdichtungsst¨oßen und Grenzschichten in Schell bewegten Gasen, Bericht des Institutes f¨ur Aerodynamik, ETH Z¨urich, No. 10
• [4] Seddon J 1967 The Flow Produced by Interaction of a Turbulent Boundary Layer with a Normal Shock Wave of Strength Sufficient to Cause Separation, ARC R & M, No. 3502
• [5] Bejm M 2000 The Influence of the Channel Depth on the Shock Wave and Turbulent Boundary Layer Interaction, PhD Thesis, IMPPAN, Gdansk, Poland (in Polish)
• [6] Doerffer P, Kania W and Bejm M 1997 Shock Wave and Turbulent Boundary Layer Interaction, IMPPAN 269/97 (in Polish)