I have a hard time understanding characteristic length in convection. I am trying to figure out the natural and forced convection inside a tube that contains couple of heating elements. Air is being heated up in this tube. Using Gr/Re^2 can tell me whether forced or natural convection dominates...
I am trying to calculate the inner surface temperature of a pipe in which a heating element is used to heat up natural gas. There is convective heat transfer from the element to natural gas and also radiation heat transfer from element to the pipe. I am given the temperature of the gas at which...
