STEPS TO RUN THIS FOLDER SIMULATIONS 

1) Open the run directory as per your console using the command: cd $FOAM\_RUN

2) Move to the case file folder using the command: cd <casefilename>

3) Run the command "blockMesh" to create and mesh the geometry from the blockMeshDict

4) Use "decomposePar" to create different processors for calculative purpose

5) Run the command "simpleFoam" for solving the flow velocity and then "scalarTransportFoam" for solving the temperature

6) Use the same 0, constant, and system folders for solving both U and T with the only changes being in the controlDict. Use the application 'simpleFoam' for U while 'scalarTransportFoam' for T

7) After solving for U and using "reconstructPar" to reconstruct the case, copy the U file from the last timestep into the 0 folder

8) Change the application in the controlDict from 'simpleFoam' to 'scalarTransportFoam'. Then run the command "scalarTransportFoam" to solve for temperature

9) After solving for U and T, the last timestep will be used for the scalar case

NOTE: All of the above mentioned steps can be done using Allrun_Flow_UP first, copying the last timestep U file into the 0 folder, changing the solver name in the controlDict, and then using Allrun_Flow_T for solving T.

10) Run the command "paraFoam" or "paraFoam -builtin" to open paraFoam for viewing or post-processing the results

11) Once the simulation is done solving for both U and T, copy the latest timestep folder into the scalar case folder. Rename the latest time step folder to 0 as we will be using the flow paramters to intialise the new scalar simulation


.... Common Errors ......

If you experience errors, check the version of OpenFOAM you're using, as it may differ from the version the case was originally set up for. 
Solutions to other common errors can be obtained in CFD groups/blog posts etc. Documentation on openfoam solvers and boundary conditions can help explain a lot.