Unlike forced convection, where a fluid is moved by an external source like a pump or fan, natural convection (or free convection) relies on . These forces are triggered by density differences due to temperature variations within the fluid. Key Concepts You’ll Master: The Grashof Number (
$$ Ra_D = \fracg \beta (T_s - T_\infty) D^3\nu^2 Pr $$ $$ Ra_D = \frac(9.81)(0.00279)(150 - 20)(0.5)^3(2.14 \times 10^-5)^2 (0.705) $$ $$ Ra_D \approx 1.55 \times 10^9 $$ Unlike forced convection, where a fluid is moved
Natural convection in gaps (e.g., double-pane windows). Sample Analytical Result For a horizontal wire with , the manual calculates a Nusselt number of approximately 1.9191.919 to find the heat rate Sample Analytical Result For a horizontal wire with
Some key topics covered in Chapter 9 include: Unlike forced convection
If your answer differs, check if your mistake was in the unit conversion, property lookup, or the selection of the Nusselt correlation.