1. The general idea

It is frequently desired to represent the influence on the flow of a thin surface which is inclined to the computational grid; and often this surface is plane. Common examples are:

Many such requirements can be met by:

The effect of these actions is as follows:

2. An Example

Input-File Library Case v206 provides an example, some results of which are shown here.

Case 1: The flow is aligned with the plate; therefore the pressure drop which it causes is very small, the effect on the flow direction likewise.
pressures velocities

Case 2: The upstream flow is horizontal and the plate inclined.
The pressure increases on the upstream side of the plate and falls on the downstream side.
The fluid is strongly deflected; and a recirculation region appears on its downstream side.
pressures velocities

Case 3: The upstream flow is horizontal and the plate inclined at a smaller angle.
The pressure increases and decreases are smaller, as is the size of the recirculation region.
pressures velocities

Case 4: The upstream flow is horizontal and the plate inclined so that the stream impinges on its lower side.
The pressure and velocity fields mirror those of case 3.
pressures velocities

Case 5: The upstream flow is horizontal; and there are now two plates positioned so as to simulate a pitched roof.
There are two recirculation regions; and the lowest pressure is on the space below the plates.
pressures velocities

2. Further developments

The angled-plate feature can be developed further in the following respects:
  1. Curved plates can be simulated by the use of shapes already present in the d_object directory and its sub-folders, for example the 'half-cylinder'.
  2. Shapemaker can be employed so as to create a 'generalised wedge' shape, formed by intersection of a grid-fitting hexagon with an arbitrarily-inclined plane.
  3. The display of the flow can be improved, both in PHOTON and the VR Viewer.
  4. Greater attention to the equations solved for the near-cut-cell pressures and velocities will bring increased conformity with physical reality.
  5. The angled plate object needs to be endowed with further attributes, such as:

These developments will form part of the NewParsol project.