2. A thin annulus of carbon steel is subject to heat treatment. It has a length...

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2. A thin annulus of carbon steel is subject to heat treatment. It has a length L = 50 mm, an inner diameter di =100 mm, a wall thickness = 1 mm, and smooth surface. A hot gas at T = 600 K flows parallel to the x- axis. If its initial temperature is T = 27C, what is the temperature of the annulus at its midpoint after being subjected to these gases for 30 sec? The velocity of the hot gas is 15 m/s. You must verify your analysis. (Hint: Consider the thickness of the annulus small compared to its radius of curvature, i.e., d; >> t, Also, d> L and d >> 8x=L). (Properties of air: p=0.774 kg/m, cp = 1021 J/kgC, = 250.7 x 10 N-s/m k=0.0373 W/m-K, Pr = 0.686) (Properties of steel: p = 7854 kg/m, cp = 434 J/kgC, k = 60.5 W/m-K, = 17.7 x 106 m/s) 2. A thin annulus of carbon steel is subject to heat treatment. It has a length L = 50 mm, an inner diameter di =100 mm, a wall thickness = 1 mm, and smooth surface. A hot gas at T = 600 K flows parallel to the x- axis. If its initial temperature is T = 27C, what is the temperature of the annulus at its midpoint after being subjected to these gases for 30 sec? The velocity of the hot gas is 15 m/s. You must verify your analysis. (Hint: Consider the thickness of the annulus small compared to its radius of curvature, i.e., d; >> t, Also, d> L and d >> 8x=L). (Properties of air: p=0.774 kg/m, cp = 1021 J/kgC, = 250.7 x 10 N-s/m k=0.0373 W/m-K, Pr = 0.686) (Properties of steel: p = 7854 kg/m, cp = 434 J/kgC, k = 60.5 W/m-K, = 17.7 x 106 m/s)