Large Eddy Simulation for Turbulent Mixing in Elliptic Jets with Round Center-Body
2009 (English)In: th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, AIAA , 2009Conference paper (Refereed)
Separate-flow exhaust nozzle systems generate jets from round nozzles that include a conical plug. The present research shows results of unsteady simulations of turbulent hot jets issued from elliptic nozzles with a conic center-body. Three geometrical configurations of the elliptic nozzle are investigated keeping the same conic plug. All designs considered were intended to match the jet stream exit area, mass flow, and thrust of an existing round conical nozzle. The first configuration in the study (C1@3:1AR) was designed with the expectation of producing a jet which would take on a 3:1 aspect ratio (AR) elliptic cross-section downstream of the center-body. For a round conical plug nozzle the inner surface of the nozzle towards exit is axisymmetric with reference to the nozzle center-line and conical. Naturally, the elliptic plug nozzle is not axisymmetric. In the major axis plane the inner surface of the elliptic nozzle towards the exit has a slope close to zero, while in the minor axis plane the slope is steeper that it would be for a corresponding round nozzle. This forces the flow stream towards the conic plug in the minor axis plane. It was observed that the 3:1AR elliptic plug nozzle (C1@3:1AR) generates a bifurcated jet. The second and the third elliptic plug nozzle geometries (C2@3:1ARnf and C3@2:1ARnf) were intended to find how the jet behavior is influenced by not forcing the flow towards the conic plug in the minor axis plane and by changing the aspect ratio of the elliptic plug nozzle to 2:1. Large Eddy Simulation (LES) approach was used for the turbulence flow modeling. In the major axis plane the largest jet spreading was found for the 3:1AR elliptic plug nozzle (C1@3:1AR), while in the minor axis plane the jet exhausting from the 2:1AR elliptic plug nozzle (C3@2:1ARnf) spread the most.
Place, publisher, year, edition, pages
AIAA , 2009.
Aerospace Engineering Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-48219ISBN: 13: 978-1-56347-969-4OAI: oai:DiVA.org:kth-48219DiVA: diva2:457013
47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition. Orlando, FL. 5 January 2009 - 8 January 2009
QC 20111117. AIAA 2009-00792011-11-162011-11-162011-11-17Bibliographically approved