Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470501979
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
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Chapter 9, Problem 9.55P
To determine
The position of can to maximize the cooling rate.
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Juice in cans 150 mm long and 60 mm in diameter is initially at 27°C and is to be cooled by placement in a refrigerator compartment at 4°C. In the interest of maximizing the cooling rate, should the cans be laid horizontally or vertically in the compartment?
Partially-frozen ice cream is being placed in a package before completion of the freezing process. The package has dimensions of 8 cm by 10 cm by 20 cm and is placed in air- blast freezing with convective heat coefficient of 50 W/(m2 K) for freezing. The product temperature is -5°C when placed in the package, and the air temperature is -25°C. The product density is 700 kg/m3, the thermal conductivity (frozen) is 1.2 W/(m K), and the specific heat of the frozen product is 1.9 kJ/(kg K). If the latent heat to be removed during blast freezing is 100 kJ/kg, estimate the freezing time.
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(a) Estimate the time required for the tile to cool to a final, safe-to-touch temperature of Tf = 42°C. Use an average tile surface temperature of T¯=(Ti+Tf)/2 to estimate the average free convection coefficient and the linearized radiation coefficient. How sensitive is your estimate to the assumed value for T¯?
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Chapter 9 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 9 - The one-dimensional plane wall of Figure 3.1 is of...Ch. 9 - Using the values of density for water in Table...Ch. 9 - Consider an object of Characteristic length 0.01 m...Ch. 9 - To assess the efficacy of different liquids for...Ch. 9 - In many cases, we are concerned with free...Ch. 9 - The heat transfer rate due to free convection from...Ch. 9 - Consider a large vertical plate with a uniform...Ch. 9 - For laminar free convection flow on a vertical...Ch. 9 - Consider an array of vertical rectangular tins,...Ch. 9 - A number of thin plates are to be cooled by...
Ch. 9 - Prob. 9.11PCh. 9 - Prob. 9.13PCh. 9 - The plate described in Problem 9.14 has been used...Ch. 9 - Determine the average convection heat transfer...Ch. 9 - Consider a vertical plate of dimension 0.025m0.50m...Ch. 9 - During a winter day, the window of a patio door...Ch. 9 - Prob. 9.20PCh. 9 - A household oven door of 0.5-m height and 0.7-m...Ch. 9 - Consider a vertical, single-pane window of...Ch. 9 - Consider laminar flow about a vertical isothermal...Ch. 9 - Consider the conveyor system described in Problem...Ch. 9 - Prob. 9.25PCh. 9 - Consider an experiment to investigate the...Ch. 9 - The vertical rear window of an automobile is of...Ch. 9 - Prob. 9.28PCh. 9 - Prob. 9.29PCh. 9 - Prob. 9.30PCh. 9 - A refrigerator door has a height and width of...Ch. 9 - In the central receiver concept of a solar power...Ch. 9 - Prob. 9.34PCh. 9 - Airflow through a long, 0.2-m-square air...Ch. 9 - Prob. 9.36PCh. 9 - An electrical heater in the form of a horizontal...Ch. 9 - Consider a horizontal 6-mm-thick, 100-mm-long...Ch. 9 - Prob. 9.39PCh. 9 - Prob. 9.40PCh. 9 - Prob. 9.41PCh. 9 - Many laptop computers are equipped with thermal...Ch. 9 - Prob. 9.43PCh. 9 - At the end of its manufacturing process, a silicon...Ch. 9 - Integrated circuit (IC) boards are stacked within...Ch. 9 - Prob. 9.48PCh. 9 - Prob. 9.50PCh. 9 - Prob. 9.51PCh. 9 - Prob. 9.52PCh. 9 - Prob. 9.53PCh. 9 - Prob. 9.54PCh. 9 - Prob. 9.55PCh. 9 - Prob. 9.56PCh. 9 - Prob. 9.57PCh. 9 - A horizontal tube of 12.5-mm diameter with an...Ch. 9 - Prob. 9.60PCh. 9 - Prob. 9.61PCh. 9 - Prob. 9.63PCh. 9 - Prob. 9.64PCh. 9 - Common practice in chemical processing plants is...Ch. 9 - Consider the electrical heater of Problem 7.49. If...Ch. 9 - Prob. 9.67PCh. 9 - A billet of stainless steel, AISI 316, with a...Ch. 9 - Lone stainless steel rods of 50-mm diameter are...Ch. 9 - Hot air flows from a furnace through a...Ch. 9 - A biological fluid moves at a flow rate of...Ch. 9 - A sphere of 25-mm diameter contains an embedded...Ch. 9 - Prob. 9.79PCh. 9 - A vertical array of circuit boards is immersed in...Ch. 9 - Prob. 9.81PCh. 9 - The front door of a dishwasher of width 580 mm has...Ch. 9 - A natural convection air healer consists of an...Ch. 9 - A bank of drying ovens is mounted on a rack in a...Ch. 9 - Prob. 9.85PCh. 9 - Prob. 9.86PCh. 9 - Prob. 9.87PCh. 9 - To reduce heat losses, a horizontal rectangular...Ch. 9 - Prob. 9.89PCh. 9 - Prob. 9.90PCh. 9 - Prob. 9.91PCh. 9 - Prob. 9.92PCh. 9 - A 50-mm-thick air gap separates two horizontal...Ch. 9 - Prob. 9.94PCh. 9 - A vertical, double-pane window, which is 1 m on a...Ch. 9 - The top surface (0.5m0.5m) of an oven is 60°C for...Ch. 9 - Prob. 9.97PCh. 9 - Prob. 9.98PCh. 9 - Consider the cylindrical. 0.12-m-diamter radiation...Ch. 9 - Prob. 9.100PCh. 9 - A solar collector design consists of an inner tube...Ch. 9 - Prob. 9.104PCh. 9 - Prob. 9.105PCh. 9 - Liquid nitrogen is stored in a thin-walled...Ch. 9 - Prob. 9.108PCh. 9 - Prob. 9.109PCh. 9 - Prob. 9.110PCh. 9 - Prob. 9.111PCh. 9 - Prob. 9.114PCh. 9 - Prob. 9.115PCh. 9 - Prob. 9.116PCh. 9 - Prob. 9.117PCh. 9 - A water bath is used to maintain canisters...Ch. 9 - On a very Still morning, the surface temperature...Ch. 9 - Fuel cells similar to the PEM cell of Example 1.5...
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