TITLE   : 2D CONVECTION OF A SCALAR STEP IN A RECIRCULATING FLOW

    BY      : CHAM Development Team           - M R Malin

    FOR     : Validation of Convection Discretisation Schemes

    PROBLEM CONSIDERED:
    - The test case is 2d pure convection of scalar step in a
      prescribed recirculating velocity field.

    - A step profile of a scalar enters a rectangular domain, and is then
      convected clockwise through 180 degrees before leaving the domain.

    - This case was devised by Smith and Hutton [1982] so as to provide a
      searching test of numerical convection schemes.

    - PHOENICS Library Case N104

    EXACT SOLUTION:

    - The step change should be convected by the recirculating flow so
      as to appear as a step change at the outlet.

    CALCULATION DETAILS:

    - Library case N104 prescribes the rotational velocity field, and
      performs calculations for the scalar field using 5 linear
      discretisation schemes and 9 non-linear discretisation schemes.

    - The calculations employ a uniform mesh of 20 by 20 cells, and
      no grid refinement studies have been conducted.

    - Solutions for selected schemes are presented below, and compared
      with the exact solution.
    

  1. Scalar Convection, Velocity Vectors & Streamlines

  2. Scalar Convection, Scalar Contours - Upwind Scheme

  3. Scalar Convection, Scalar Contours - QUICK Scheme

  4. Scalar Convection, Scalar Contours - SUPERBEE Scheme

  5. Scalar Convection, Scalar Profile at Y=0 - Linear Schemes

  6. Scalar Convection, Scalar Profile at Y=0 - Non-Linear Schemes