| OCR Text |
Show Recirculation Zone I[A!l~J[J'~:~[i]!JI[[~lijiii-li~4~i'I~I?it;'I-lillli!"I~4:::/s Numerical model Vector Scale : 19.4m/ s ! X ~ , (1) Gas Flow : 100m/s (1-Center Nozzle), Z 1 1 Air Flow : 40m/ s (4-0utside Nozzles) Reci~culation Zone Y • Z - -". - =';-~~;'5t--ii#J Air lOOmIs ~ X 1 , ! ,~~::~~_-:g:- z- IT '/)....-- : : ~ ~ ; ~ ~ = ~Y'! :::: ~ Gas 40m/s • Computer Code : PHOENICS . . ;. !!:.. - - ,. - ~ ~ -r ~ i i. Vector Scale : 19.4m/s " , • X ___I Recirculation Zone -l • k-E. Model and Eddy-dissipation Model (2) Gas Flow: 40m/s (1-Center Nozzle), Z Air Flow : 100m/ s (4-0utside Nozzles) • Adiabatic Wall . • No Buoyancy Effect Fig. 2 Flow pattern 2.2 EFFECT OF THE AIR VELOCITY ON THE ENTRAINMENT OF COMBUSTION PRODUcrS One of the important features of FDI is effective use of self-induced FOR resulting from direct injection of gas and air .. The velocity of the combustion air is significant in creating the entrainment of the combustion products. Fig.3 summarizes results from the mathematical modeling. 21 -:::.S2 0 Ua : 20m/s c 19 .0.. . ..r".o-. 17 c Q) 0c 15 0 U c 13 I Q) ()) Ua : 100m/s >~< 11 0 9 0 180 360 540 , 720 Axial Distance from Air Nozzle mm Fig. 3 02 concentration of air flow 4 |
