3013-11 Hw-7

# 3013-11 Hw-7 - Are the results what you would expect? 3....

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1 of 1 CHE 3013 Rate Operations I Fall 2011 Homework 7 Due: Monday, October 10, 2011 4 problems, 6 points each, 24 points total. 1. Water at 320 K and 1 bar flows with a velocity of 1.0 m/s over a flat plate 1.0 m long and 0.5 m wide that has a uniform surface temperature of 340 K. (a) Plot the local heat transfer coefficient, h ( x ) , as a function of distance from x = 0.05 meter to the end of the plate. Suggestion: Use the properties from Table A.6, Incropera, et al., 6 th or 7 th Edition, and set up a spreadsheet to calculate local Nusselt numbers. Eleven points will be sufficient, i.e., 0.05, 0.1, 0.2, . . . , 1.0 m. (b) Calculate the average heat transfer coefficient for the plate. 2. Problem 7.41, Incropera, et al., 6 th Edition (7.46 in 7 th Edition) Compare the heat transfer coefficients for air and water to those calculated using the Zukauskas correlation (Equation 7.53) For Part b, generate the plot for water only using the Zukauskas correlation.
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Unformatted text preview: Are the results what you would expect? 3. Problem 7.88, Incropera, et al., 6 th Edition (7.94 in 7 th edition), using the Zukauskas correlation for tube bundles in cross flow (Equation 7.64). Suggestion: Set up a spreadsheet with properties evaluated at T i and T s . Guess a value of T o , evaluate the properties at T m by interpolation, and calculate Nu . Now ( ) LM T DL h N q = From an energy balance, ( ) i o p T T C m q = Use the Solver tool to set the difference between the two heat-transfer rates equal to zero by changing T o . The specific heat capacity is evaluated at the average temperature, T m . 4. Repeat Problem 3 using a triangular staggered pitch with S T = S D = 60 mm. Which layout has the higher average heat transfer coefficient? Which has the higher pressure drop? Why?...
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## This note was uploaded on 10/11/2011 for the course CHE 3013 taught by Professor Staff during the Fall '11 term at Oklahoma State.

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