Chapter 4: Transient Conduction

Problems for Chapter 4 Note: These problems are NOT your homework assignments. Homeworks will be assigned in class on a separate handout. An aluminum sphere with a 2 cm diameter is placed into a warm water bath at 40 ēC. The initial temperature of the sphere is 20 ēC. The convection coefficient between the sphere and water is 400 W/m2K. Calculate the temperature at the center of the sphere after 10 seconds. (Properties of aluminum are given in Chapter 2.) You are cooking a small potato in boiling water. Approximating the potato to be a sphere with diameter of 4 cm, estimate the temperature after 20 minutes at a) the center of the potato, and b) at r = 1 cm. ρpotato = 1050 kg/m3 cp,potato = 3.64 kJ/kgK kpotato = 0.55 W/mK αpotato = 1.5×10-7 m2/s h = 400 W/m2K Back to Chapter 4 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