Tertiary flow effects on a co-axial ducted jet
2012 (English)In: 50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition / [ed] AIAA, AIAA , 2012, AIAA 2012-0064- p.Conference paper (Refereed)
Long duct mixed flow exhaust systems operate as noise suppression devices under the concept that the surrounding secondary long duct shields some of the fine-scale turbulent mixing noise generated between the primary and secondary streams. Numerical results concerning a round co-axial ducted jet at Baseline (without tertiary flow effects) are compared against data obtained for two tertiary flow conditions of 0.15 and 0.30 co-flow Mach numbers (Mcf), respectively. The computations are carried out by using the Reynolds-Averaged Navier-Stokes (RANS) formulation with Realizable k-? turbulence model. At Baseline, comparisons between the computational predictions and Stereoscopic Particle Imaging Velocimetry (SPIV) experimental data just downstream of the nozzle exit show a good agreement. In the fully merged zone of the jet, self-similarity is achieved at the downstream axial location of x ~ 9D (Baseline case, Mcf = 0), where D is the diameter of the long duct nozzle’s exit. The tertiary flow increases the length of the potential core region while limiting the radial spread of the jet. With tertiary flow, self-similarity is achieved at x ~ 11D and at x ~ 13D for the co-flow Mach numbers (Mcf) of 0.15 and 0.30, respectively. When considering a tertiary flow of Mcf = 0.30, the maximum turbulence intensity levels in the outer shear layer of the jet decreased to about 20% of the baseline case.
Place, publisher, year, edition, pages
AIAA , 2012. AIAA 2012-0064- p.
compressible jet, long duct mixer, flight effects
Aerospace Engineering Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-63760ScopusID: 2-s2.0-84871914291OAI: oai:DiVA.org:kth-63760DiVA: diva2:482471
50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition;Nashville, TN;9 January 2012through12 January 2012
QC 201301162012-01-242012-01-242013-01-16Bibliographically approved