7.12 Hydraulic Structures
7.12.2 Description
In addition to the hydraulic structures described in Section 5.17, TUFLOW FV supports simulation of hydrodynamic destratification devices. These are included as hydraulic structures and are designed to be used in 3D simulations where AD is turned on and vertical density stratification is present, rather than in 2D or well mixed environments.
7.12.2.1 Structure Types
Table 7.30 presents the supported destratification structure types and provides example applications. Links in the Model Implementation column direct the reader to dedicated sections that describe configuration requirements and TUFLOW FV syntax examples.
| Model Implementation | Description |
|---|---|
| Bubble Plumes | Represent bubble plume destratification devices. Example applications include the thermal destratification of water supply reservoirs or lakes. |
7.12.3 Bubble Plumes
Bubble plumes are systems that release compressed air bubbles from submerged perforated pipes. Released bubbles move upwards and in doing so entrain and detrain ambient waters to provide a degree of hydrodynamic mixing.
Bubble plume destratifiers are configured within a structure block using the
For bubble plume model outputs see Section 7.13.7.1.
| Destratification Unit | Description |
|---|---|
| Bubbler | Bubble plume with airflow rate specified at the structure depth. |
| Compressor | Bubble plume with airflow rate specified at atmospheric pressure. |
7.12.3.1 Bubbler
- Connection type: Zone
- Required commands:
Destratification Unit ,Properties - Notes:
- Specific to bubble plumes, a zone polygon should not include more than one 2D TUFLOW FV cell
- The flow rate specified is per plume at the structure depth. This flow rate is used to compute single plume entrainment and detrainment rates
- The number of ports is the number of plumes within each specified zone polygon. If multiple plumes are specified within one structure then entrainment and detrainment rates from the single plume simulation are multiplied accordingly
- Calculation parameters are explained in Appendix B.12.1.8
- Can be optionally controlled with a control block. If a control block is used, the flow rate specified in the properties block is ignored and the control timeseries is applied instead (see Section 7.12.4)
The following example configures a constant airflow per plume at the diffuser head.
7.12.3.2 Compressor
- Connection type: Zone
- Required commands:
Destratification Unit ,Properties - Notes:
- Specific to bubble plumes, a zone polygon should not include more than one 2D TUFLOW FV cell.
- The flow rate specified is per plume at atmospheric pressure. This flow rate is used to compute single plume entrainment and detrainment rates
- The number of ports is the number of plumes within each specified zone polygon. If multiple plumes are specified within one structure then entrainment and detrainment rates from the single plume simulation are multiplied accordingly
- Calculation parameters are explained in Appendix B.12.1.8
- Can be optionally controlled with a control block. If a control block is used, the flow rate specified in the properties block is ignored and the control timeseries is applied instead (see Section 7.12.4)
The following example configures a constant airflow per plume at atmospheric pressure.
7.12.4 Operational Control
Operational control for AD hydraulic structures follows the same workflow as the 2D HD class. This section adds only the bubble plume specific control parameters and provides a small implementation example.
Operational control for the AD simulation class is implemented through the same structure block nesting pattern used in 2D HD (see Section 5.17.11) with one or more nested
7.12.4.1 Control Parameters
Only two additional control parameters are available for AD bubble plume structures. These parameters are listed in Table 7.32.
| Control_Parameter | Description |
|---|---|
| Airflow_Bubbler | Air flow rate per plume (m\(^3\)/s) at diffuser head. |
| Airflow_Compressor | Air flow rate per plume (m\(^3\)/s) at atmospheric pressure. |
7.12.4.2 Control Types
Bubble plume control uses the same control type framework as 2D HD. For bubbler and compressor airflow rates only the
7.12.4.3 Control Block
The syntax is the same as described in Section 5.17.11.4. The only AD specific requirement is that the control parameter must be one of the following.
- Airflow_Bubbler with
Destratification Unit == Bubbler - Airflow_Compressor with
Destratification Unit == Compressor
When a control block is specified, the Properties flow value is not used. Control data is read from the
7.12.4.4 Airflow_Compressor and Airflow_Bubbler Control Examples
The example below applies a timeseries control using
The second example applies a timeseries control using