low Reynolds number problem
 

pls anybody could tell me how can i define Reynolds number in a forced convection over 4 planar heat sources placed in line inside a test section of a wind tunnel?
the Re curresponds to flow over a flat plate is very low. but its not getting converged in laminar model of FLUENT.:confused:

The characteristic length for the flow over blunt bodies is usually the width of the body.

the heat source is similar to flat plate. but 4 such heat sources are arranged in tandem with a gap of 10 mm between them. so can i consider its total length or length of single heat source for defining the Reynolds number?

Why is it so important to define a Reynolds number for this case?
For complex flows, the choice of a characteristic length is quite arbitrary.