Chapter 1: Overview of Heat Transfer

Problems for Chapter 1 Note: These problems are NOT your homework assignments. Homeworks will be assigned in class on a separate handout. Define the following heat transfer situations as either conduction, convection, radiation, or a combination of the three. Please also clearly state what two objects the mode of heat transfer is between and the direction of heat transfer. For example: A person with a headache holds a cold ice pack to his/her forehead. Answer: Conduction occurs from the person’s forehead to the ice pack. The sun shines brightly on a car, making the black upholstery very hot. A small 4" fan is installed in the back of a computer to help cool the electronics. Potatoes are boiled in water. A turkey is being roasted in the oven. An ice cube is placed on a metal tray and left out of the freezer. A loaf of freshly baked bread is left to cool on a cooling rack. The dimension of the loaf is as described in the figure, and its surface temperature is 120 ºC. The temperature of the air is 20 ºC, and the convection coefficient from the loaf to air is 10 W/m2K. Emissivity of the bread is 0.76, and its conductivity is 0.121. Based on these information, calculate the total heat loss from the bread. A cup of hot coffee sits on the table. Describe all modes of heat transfer that contributes to the cooling of the coffee. Back to Chapter 1 TOC     << | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | >> HOME | GENERAL INFO | LECTURE NOTES | SYLLABUS | HOMEWORK | LAB INFO Send questions and comments to Haruna Tada ©2002 Mechanical Engineering Department*Tufts University*Medford, MA 02155