Near-field mixing of jets issuing from an array of round nozzles
2014 (English)In: International Journal of Heat and Fluid Flow, ISSN 0142-727X, E-ISSN 1879-2278, Vol. 47, 84-100 p.Article in journal (Refereed) Published
This article presents results of an experimental study of the confluence of low Reynolds number jets inthe near field of a 6 6 in-line array of round nozzles. Particle Image Velocimetry (PIV) and Laser DopplerAnemometry (LDA) were employed to measure mean velocities and turbulence statistics. The comparisonof the results from PIV and LDA measurements along different cross-sectional profiles and geometricalcenterlines showed good agreement. However, LDA enabled more accurate results very close to the nozzleexits. The evolution of all the individual jets in the array into a single jet showed flow regions similarto twin jets (i.e., initial, converging including mixing transition, merging and combined regions). The lateraldisplacements play an important role for a confluent jet, where all jets to some degree are deflectedtowards the center of the nozzle plate. The jet development in terms of velocity decay, length of potentialcore and lateral displacement varies significantly with the position of the jet in the array. A comparisonwith single jet and twin jets flow showed considerable differences in velocity decay as well as locationand velocity in the combined point. The flow field of confluent jets showed asymmetrical distributionsof Reynolds stresses around the axis of the jets and highly anisotropic turbulence. Additionally, the lateraldisplacement as well as the turbulence development in the proximal region of the studied confluent jetwas shown to be dependent on Reynolds number.
Place, publisher, year, edition, pages
Elsevier, 2014. Vol. 47, 84-100 p.
Low Reynolds number round jet, Jet-to-jet interaction, Multiple jet array, Confluent jets, Particle Image Velocimetry (PIV), Laser Doppler Anemometry (LDA)
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:liu:diva-106380DOI: 10.1016/j.ijheatfluidflow.2014.01.007ISI: 000336773700008OAI: oai:DiVA.org:liu-106380DiVA: diva2:715796
FunderSwedish Research Council, 2008-31145-61023-37