5.2 Three-Dimensional Heat Equation

5.2 Three-Dimensional Heat Equation

  • We are going to derive the three-dimensional heat equation using a different method.
  • The next job is to quantify the statement.
    • The inflow is negative because this quantity is positive.
  • The term "rate of generation inside" is meant to indicate the rate of conversion of energy from other forms to thermal.

  • This is how the argument goes.
    • The integral over that sub region would be either positive or negative.
  • The minus sign makes the heat flow "downhill" from hotter to colder regions.

A given function is 1

  • The given function is 2.

  • The three-dimensional problem for a solid in the form of a rectangular parallelepiped was set up.

  • The top and bottom surfaces should be insulated.

  • They transfer heat from one place to another.

  • A full, three-dimensional problem is difficult to solve, so we often look for ways to reduce it to two or even one dimensions.

  • The averaging process was applied to Eqs.