# Tonpilz Transducer in Vacuum

## Defining the 2D Geometry

The coordinates of the points you will need to create are shown in the table below, for reference. It is better for acoustic radiation problems to position the origin of the acoustic source (center of the piston face) at the origin of the global coordinate system. Although, we do not consider the acoustic radiation problem in the first part of this tutorial, it will save time later to follow the same rules. For this reason, the solid part of the transducer is located in the negative X region, and the fluid domain is in the positive X region.
Note that because ATILA uses the X axis as the axis of axisymmetry, the points are all in the positive Y region of the plane. The coordinates of the points you need to create are arranged in the following table.

|  |  | (-39,23) | (-33,23) |  |  |  |
| (-55,20) |  | (-39,20) |  |  |  | (-8,20) | (0,20)
|  |  |  | (-33,18) | (-23,18) | (-13,18) |  |
(-64,10) | (-55,10) |  |  |  |  |  |  |
(-64,6) | (-55,6) |  |  | (-33,6) | (-23,6) | (-13,6) | (-8,6) | (0,6)
|  | (-50,4) |  |  |  | (-13,4) |  |
(-64,0) |  |  |  |  |  |  |  | (0,0)

Remember that there is more than one way to enter points in GiD in Cartesian and polar coordi-nates. Please refer to the online help in GiD for further details.

Previous | TOC | Next