In Chapter 4, you were asked to determine the time required for an aluminum extrusion to cool

Question:

In Chapter 4, you were asked to determine the time required for an aluminum extrusion to cool to a maximum temperature of 40°C. Repeat these calculations, but determine the convection heat transfer coefficients over the extrusion, assuming that air is directed perpendicular to the right face of the extrusion at a velocity of 15 m/s. Conditions at the front resemble that of a jet impinging on a surface, whereas conditions on the upper and lower surfaces resemble those of flow over a plate; see accompanying sketch. The rear face presents a problem, and some estimates and constructive ideas about calculating the heat transfer coefficients are left to the designer.