(a) Select substrate-wall and wall in the Names selection list.
(b) Click the Display... button under Geometry Attributes to open the Display Properties panel.
i. Set the Transparency slider to 70.
ii. Click Apply and close the Display Properties panel. (c) Click Apply and then close the Scene Description panel. 7. Display velocity vectors on the y=0 surface. Display /Vectors...
(a) Enable the Draw Grid option. The Grid Display panel will open.
i. Make sure that substrate-wall and wall are selected in the list under Surfaces. ii. Click Display and close the Display Grid panel. (b) Enter 5 for the Scale. (c) Set Skip to 1.
(d) Select y=0 from the Surfaces selection list. (e) Click Display and close the Vectors panel.
The flow pattern shows that the flow enters the catalytic converter as a jet, with recirculation on either side of the jet. As it passes through the porous substrate, it decelerates and straightens out, and exhibits a more uniform velocity distribution.
This allows the metal catalyst present in the substrate to be more effective.
Figure : Velocity Vectors on the y=0 Plane
8. Display filled contours of static pressure on the y=0 plane. Display /Contours...
(a) Enable the Filled option.
(b) Enable the Draw Grid option to open the Display Grid panel.
i. Make sure that substrate-wall and wall are selected in the list under Surfaces. ii. Click Display and close the Display Grid panel.
(c) Make sure that Pressure... and Static Pressure are selected from the Contours of drop-down lists.
(d) Select y=0 from the Surfaces selection list. (e) Click Display and close the Contours panel.
Figure : Contours of the Static Pressure on the y=0 plane The pressure changes rapidly in the middle section, where the fluid velocity changes as it passes through the porous substrate. The pressure drop can be high, due to the inertial and viscous resistance of the porous media. Determining this pressure drop is a goal of CFD analysis. In the next step, you will learn how to plot the pressure drop along the centerline of the substrate.
9. Plot the static pressure across the line surface porous-cl. Plot /XY Plot...
(a) Make sure that the Pressure... and Static Pressure are selected from the Y Axis Function drop-down lists.
(b) Select porous-cl from the Surfaces selection list. (c) Click Plot and close the Solution XY Plot panel.
Figure : Plot of the Static Pressure on the porous-cl Line Surface
In Figure , the pressure drop across the porous substrate can be seen to be roughly 300 Pa.
10. Display filled contours of the velocity in the X direction on the x=95, x=130 and x=165 surfaces. Display /Contours...
