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1. A hole in the bottom of a large open tank discharges water to the atmosphere. If the exit velocity in the absence of losses is Ve, find the loss coefficient for the hole if the actual velocity is Ve/2. Assume turbulent flow. 2. Air enters a duct at a speed of 100 m/s and leaves it at 200 m/s. If no heat is added to the air and no work is done by the air, what is the change in temperature of the air as it passes through the duct?  

please show how to derive h using nusselt equation and solve for qheatloss

2 A wire of diameter D = 2 mm and uniform temperature T has an electrical resistance of 0.01 N/m and a current flow of 20 A. (a) What is the rate at which heat is dissipated per unit length of wire? What is the heat dissipation per unit volume within the wire? (b) If the wire is not insulated and is in ambient air and large surroundings for which T = Tsur = 20°C, what is the temperature T of the wire? The wire has an emissivity of 0.3, and the coefficient associated with heat transfer by natural convection may be approximated by an expression of the form, h = C[(T-T)/D]¹/4, where C = 1.25 W/m7/4.K5/4 (c) If the wire is coated with plastic insulation of 2-mm thickness and a thermal conductivity of 0.25 W/m.K, what are the inner and outer surface temperatures of the insulation? The insulation has an emissivity of 0.9, and the convection coefficient is given by the expression of part (b). Explore the effect of the insu- lation thickness on the surface temperatures. Note: 1. The metal wire…

the pressure drop across the tube bank, and (c) the rate of condensation of steam inside the tubes. Evaluate the air properties at an assumed mean temperature of 35°C and 1 atm. Is this a good assumption?solve this part too

1. Consider a 1000 MW power plant located in a rural area with 15 ton/day SO2 emissions from a 100 m high stack. The velocity and temperature of the stack gases lead to an effective stack height of 50 m above the physical stack. Estimate the ground level concentration as a function of distance downwind under the following conditions. The emissions are into a clear daytime atmosphere with wind (at 10 m) of 5 m/s. b. The emissions are into a clear nighttime atmosphere with wind (at 10 m) of 2 m/s. The conditions of a. except there is a strong elevated inversion at an altitude of 200 m. a. С.

On a day when wind is blowing over a lake (T(water) =20°C) at 5 m/s, which side of the air-water interface will be rate-limiting on the flux of Ethyl benzene (i.e. va or vw)?

According to nature of flow, convective heat transfer is classified into natural convection and forced convection. By taking specific examples, explain how the natural convection and forced convection arises in them.