HW5 solution

HW5 solution - Homework #5 Name _ Problem I. The...

This preview shows pages 1–3. Sign up to view the full content.

Homework #5 Name _______________________________ Problem I. The temperature of a gas stream is to be measured by a thermocouple whose junction can be approximated as a 1.2-mm-diameter sphere. The properties of the junction are k=35 W/m 0 C, ρ =8500 kg/m 3 , and C P = 320 J/kg 0 C, and the heat transfer coefficient between the junction and the gas is h=65 W/m 2 0 C. Ia. Determine if lumped system analysis can be used for the heat transfer analysis of this system. Ib. Determine how long it will take for the thermocouple to read 99% of the initial temperature difference.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Problem II. Stainless steel ball bearings ( ρ =8085 kg/m 3 , C P = 0.480 kJ/kg 0 C, α =3.91 x 10 -6 m 2 /s) having a diameter of 1.2 cm are to be quenched in water. The balls leave the oven at a uniform temperature of 900 0 C and are exposed to air at 30 0 C for a while before they are dropped into the water. If the temperature of the balls is not to fall below 850 0 C prior to quenching and the heat transfer coefficient in the air is h= 125
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/08/2010 for the course ME 109 taught by Professor Staff during the Spring '08 term at San Jose State.

Page1 / 5

HW5 solution - Homework #5 Name _ Problem I. The...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online