A method for measuring the convection heat transfer from spheres has been proposed. A 20-mm-diameter copper sphere with an embedded electrical heater is to be suspended in a wind tunnel. A thermocouple inside the sphere measures the sphere surface temperature. The sphere is supported in the tunnel by a type 304 stainless steel tube with a 5-mm OD, a 3-mm ID, and 20-cm length. The steel tube is attached to the wind tunnel wall in such a way that no heat is transferred through the wall. For this experiment, examine the magnitude of the correction that must be applied to the sphere heater power to account for conduction along the support tube. The air temperature is 20°C, and the desired range of Reynolds numbers is 103 to 105.
