Developing Excel Macros For Solving Heat Diffusion Problems

This paper describes the use of Microsoft Excel Spreadsheet and Macro in solving diffusion problems. A one dimensional heat diffusion equation was transformed into a finite difference solution for a vertical grain storage bin. Crank-Nicholson method was added in the time dimension for a stable solution. The Excel spreadsheet has numerous tools that can solve differential equation transformed into finite difference form for both steady and unsteady boundary conditions. Its iterative scheme is easy in solving a problem with steady boundary condition. This paper describes a method to solve heat diffusion problem with unsteady boundary conditions using Excel based macros. Results obtained from the solution agreed well with the measured product temperature distribution for a period of two and half years.