- The problem concerns the rise of a smoke plume as it is carried along by an air stream having an imposed shear-flow velocity profile at the inlet of a long tunnel

- Three-Dimensional steady flow with buoyancy
- The Cartesian computational grid has 40 intervals in width x, 40 in height y, and 625 in length, z
- Solved-for variables are three velocities, pressure, temperature and smoke concentration
- At inlet, the longitudinal velocity profile inceases linearly with height; and a rectangular-sectioned stream of hot smoke enters, the remainder being occupied by atmospheric-temperature air
- Buoyancy causes flow in cross-section to exhibit vortices

- This case shows how the parabolic option can be employed with advantage for fine-grid calculations on machines of modest size.
- Although there are one millionn cells in all, a computer with memory big enough for only 1600 will suffice

1.The computational grid section across the tunnel

2. An animated sequence of smoke contours

at successive distances along the tunnel

3. Velocity vectors at the tunnel exit