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Question 1 [100 pts.] An electronic device is cooled by Oz through eight rectangular channels drilled in the casing as shown in the figure. The channels are a=6.0 mm diameter and L=0.25 m long. Heat is generated in the device, resulting in approximately uniform heat flux to the fluid in the cooling passage. To determine the heat flux, cooling fluid average outlet temperature is measured and found to be Te=50°C. If the fluid enters the channels at a temperature of T=15°C and flows at a velocity of V=4 m/s, a) calculate the rate of heat generated by the electronic device considering only the heat transfer between the cooling fluid and the device. (10 Points) b) Find the Reynold's number and determine the flow type? (20 Points) c) Calculate the Nusselt number. (40 Points) d) Find the cooling channel maximum surface temperature. (20 points) e) Discuss using graphs and charts the validity of this cooling system if the maximum allowable temperature of the device is 110°C? (10 Points) (for O2, use k = 0.01696 W/m.K, Pr = 0.766, u = 1.517 x 10-5 Pa.s, Ms = 1.613 x 10-5 Pa.s, Cp = 855.5 J/kg.K, p = 1.754 kg/m?) m a