We have an exciting announcement about badges coming in May 2025. Until then, we will temporarily stop issuing new badges for course completions and certifications. However, all completions will be recorded and fulfilled after May 2025.
Heat Transfer

Heat Transfer

How do I determine if I must consider natural or forced convection?

Tagged:

    • FAQFAQ
      Participant

      A natural or forced convection problem can be determined by using the Richardson number which is defined as the ratio of natural convection to forced convection: Ri=gβΔTL/(U_0)^2 where U_0 is the velocity of the flow [m/s] ΔT is the maximum temperature difference within the fluid region L is the representative length [m] g is the gravitational acceleration [m/s2] β=1/ρ*(∂ρ/∂T) is the volume expansion coefficient [1/K] When Ri=1, both natural and forced convection need to be considered. When Ri<<1, natural convection can be neglected When Ri>>1, forced convection can be neglected