Hello CFD friends,

I am working on DNS of diffusion flames. flame is emmiting from round shape nozzle. so i can call it as round jet. for this jet ,there is an experimental data, and i want to run my simulation and compare with this experimental results, here my problem is the experiment has been carried out at Reynolds number of 16000, i want to simulate this flame,, so i have to set Reynolds number ,,how i have to set Reynolds number in my simulation,,i mean i have to give as it is 16000 or i have to calculate based on some other methods,,in the literature , i have seen , most of the flames are doing simulation based on orifice diameter ,,what is this,, i didnt understand this,, please help me ,,

Hi, chinthakindi,

Reynolds number can be set directly in dimentionless N-S equations, if you are using a dimentional N-S, you can check how the Reynolds number is set in your program. Usually, people calculate the Reynolds number using characteristic length, density, velocity, and viscosity, and the length usually is the diameter of the nozzle, the density and viscosity can be determined with the flow conditions, the only parameter you can set is only velocity, so just using 16000 to obtain the velocity, you can get your result!

Good Luck!

Zhou Hua