{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Homework 5 solutions

# Homework 5 solutions - Homework 5 1(15 pts In Class 9 we...

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

Homework 5 1. (15 pts) In Class 9 we looked at an infinite cylinder with a convection coefficient h = 1000 W/m 2 -K. Let’s say the centerline temperature must be increased from T i = 300 K to T = 750 K. Plot the centerline temperature distribution vs. time for h = 100, 500 and 1000 W/m 2 -K. In each case, stop the calculation when T = 500 K. (10 pts) How long does it take to reach a centerline temperature of 500 K for each convection coefficient.(3 pts) Can any of these be treated as lumped capacitance? θ* o = T(0,t) - T /T i - T = C 1 exp(-ζ 1 2 *Fo) T = C 1 exp(-ζ 1 2 *Fo)( T i - T ) + T With h = 100, it can be treated as lumped capacitance.

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

View Full Document
2. (20 pts) One way to determine thermal conductivity of a solid is to embed a thermocouple in a thick slab and measuring the response to a change in temperature. Consider a material with a density of 950 kg/ m3 and a c = 1100 J/kg-K. The material is heated to a uniform temperature of 100 o C and the cooled by passing air at 25 o C over one surface. If a thermocouple is embedded a distance of 10 mm below the surface, the h
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}