Heat Transfer - Rapid cooling of steel cylinder

[Gu-Ute1]

Homework Statement

A steel cylinder of diameter 8cm and length 12cm is initially at 600°C. It is placed in oil at 20°C for rapid cooling, for case hardening of the surface layer. The value of h is 60W/m2 K. Use the numerical method.

a. Determine the time in which the maximum internal temperature level decreases to 500°C.

b. What is the minimum metal temperature at this time and where does it occur?

c. Plot the temperature distribution at that time along the cylinder axis.

Homework Equations

Not sure on what equations are relevant to this question

The Attempt at a Solution

With regards to the attempt of this question I really don't know where to start, I have been through textbooks in an attempt to find similar question with no success. However after reading I can gather, a thin rectangular shape can be constructed along the cylinders axis, so cartesian coordinates can be used to find the variation in temperature using the initial and boundary conditions surrounding the cylinder.

 

[haruspex]

It says "use the numerical method", not "use a numerical method". This suggests it refers to a method you have been taught. No-one else can know what that is.