hi all i constructed a cylindrical combustion chamber having air inlet and fuel is suplied by injection,out side of this combustion chamber heat exchanger is provide like cylindrical which extracted heat from out side of the combustion chamber. if heat exhanger velocity increse than is there any effect on flue gas temperature.i have kept velocity of cold air in heat Exh is 5m/s i am getting flue gas temp is 3500 K and at burner temperature is 3700 K. And LDO is used as fuel which is injected at velocity 50 m/s and air velocity 10 m/s. Intilizatin velocity is 10m/s and temperature is 2000 K.i also want to know whether the intilization to be made by taking all-zone is there any effect on which zone we select in inilization ?i have taken viscous k-epsilon model discrete phase and non-primixed combustion give me the way to decrease the exhaust temp of flue gas. thanks a lot

Just take all zone and set the temperature at 2000 K. (It works on my example). I have one question for you ! I am trying to model low temperature boiler (only 25 kW), and I have problem in defining swirl flow. The fuel is light oil (non-premixed combustion, k-epsilon model-RNG, have also injection-DP-cone). At the air inlet the axial velocity of air is 1.5 m/s, and then the air flows through the plate (die Stauscheibe - at the exit of burner)and here I have to define swirl velocity to generate swirl flow in combustion. I didn't draw that plate in Gambit. I just have one face (I defined it as interior in Gambit) where I should define swirl velocity. Please .. help me if you know the answer..

hi i make my problem but u given your problem let try i doing my problem in that only LDO is injected. in your problem non_premixed u have put a circular plate in just ahed of injection so swirled is produced. i think u give diagram just free hand sketch in word my e_mail is ms_project05@rediffmail.com