Form for the definition of sources for the dispersion calculation. These elements can be placed also under Graphical Tools for drawing objects.
A source is defined as cuboid, which can be rotated around the vertical axis. Without rotation Xq and Yq in the top-view designate the lower left corner of the cuboid (rectangle) and Hq the distance from the ground. Aq, Bq and Cq are its expansions in x -, y and z-direction. The angle Wq marks a counter-clockwise rotation around the lower left corner in degrees. One or more expansions can be zero, so the definition of point -, line -, surface and volume sources is possible.
Symbols like. Qq will also be shown in the column title. If the data are too wide in the columns, symbols in parentheses will be hidden, they can be made visible by widening the column.
With the Source-Wizard one can edit a source with the most common parameters for different source types. The Source-Wizard can be invoked with the so named button, or via right mouse button click. When no source was selected, a new one will be added to the table.
Order Number, assignment will change when rows are inserted or tables are sorted.
Arbitrary name of the source.
With this switch a source with all dependent variables can be switched off. It is not considered thereby in the computation.
X-coordinate of the source (default value 0 m = in the middle of the computation grid).
Y-coordinate of the source (default value 0 m = in the middle of the computation grid).
Height of the source (lower edge) over the ground (default value not available, this parameter must be set).
Heat Emission (Qq)
Heat Emission Mq of the exhaust gas in MW (default value 0 MW). It is to be calculated as Mq = 1.36 · 10-3 · (Tq - T0) · R, with T0=10°Celsius and the exhaust volume rate R of the exhaust gas (moist) in the standard state. If only the parameter Qq and not Vq is indicated, then the waste gas plume rise is computed only with the thermal portion (as in the TA Luft 86). Also see: How to declare components as situation-dependent and How to declare components as time-dependent.
Time Scale Tu (Sq)
Time scale Tu (see VDI 3945 part 3 section D5) for the computation of the waste gas plume rise. If this parameter is indicated, then the waste gas plume rise is not calculated after VDI 3782 part 3, but according to the procedure indicated in VDI 3945 part 3 section D5, where the parameter Vq is interpreted as additional speed U. Sq can be made time-dependent.
Exhaust Velocity (Vq)
The exhaust velocity of the exhaust gas (default value 0 m/s). This parameter is effective only if the parameter Dq is greater zero. Also see: How to declare components as situation-dependent and How to declare components as time-dependent
Diameter of the source (default value 0). This parameter is used only for the computation of the waste gas plume rise after VDI 3782 part 3, see Qq.
The following parameters are not necessary for stacks (point sources).
Rotation Angle (Wq)
Angle of rotation of the source around a vertical axis at the lower left corner (default value 0 degrees).
Expansion of the source in z-direction (default value 0).
Expansion of the source in y-direction, if no rotation is present (default value 0).
Expansion of the source in x-direction, if no rotation is present (default value 0).
Exhaust gas temperature in degrees Celsius (default value 0) 1). The indication of Tq is necessary when exhaust gases are directed thru a cooling tower. For other sources, Tq will be used (if a value greater than 10 is set) to calculate the Heat Emission Qq after Qq=1.36e-3*(tq-10)*vq*3.14159*dq*dq/4.
Relative Humidity (Rq)
Liquid water content of the waste gas plume in kg/kg 1) when the exhaust gases are directed thru a cooling tower (default value 0). If this parameter is greater than 0, then waste gas plume rise for that source is computed in accordance with VDI 3784 part 2.
Liquid Water Content (Lq)
Relative Humidity of the waste gas plume in % 1) when the exhaust gases are directed thru a cooling tower1) (default value 0). If this parameter is greater than 0, then waste gas plume rise for that source is computed in accordance with VDI 3784 part 2.
Describing Text. The Comment will not shown in the Report by default, but can be added in the Setup in the Report.
1) the program VDISP.exe (available at www.vdi.de/vdisp) must be in the same folder as AUSTAL2000.exe (normally this is also the program folder).
See also: Operation within the tables