4.24. Reservoir¶
4.24.1. RSVOIR (class)¶
Fig. 4.24.1 Pressure head boundary condition¶
Supplier type
type label |
Description |
active |
|---|---|---|
RSVOIR (reservoir) |
Constant or time-dependent head |
No |
4.24.1.1. Mathematical model¶
A RSVOIR prescribes the head in a certain point of the system.
The head (level) is constant during the steady state calculation. During the transient calculation the head varies in time in accordance with the net inflow into the reservoir.
The RSVOIR is a reasonable model, if the storage area is relatively small (compared with the net in- or outflow during the transient calculation). If the level variation during the transient calculation is negligible, the component “BOUNDH (reservoir)” on page 225 should be used instead.
To achieve the specified head the RSVOIR has to supply or consume fluid to or from the system. The discharge will be determined by the continuity equation for the H-node to which the RSVOIR is connected. If a RSVOIR is located between two pipes it actually decouples the system: the pipes are behaving independently of each other and waterhammer waves will reflect completely (reflection factor -1).
4.24.2. RSVOIR (reservoir)¶
4.24.2.1. Hydraulic specifications¶
description |
input |
unit |
range |
default |
remarks |
|---|---|---|---|---|---|
Area type |
Constant/Variable |
[m] |
|||
Area |
Real |
[m2] |
If Area type = constant |
||
Height-area table |
Table |
If Area type = variable |
|||
Head at t = 0 |
Real |
[m] |
See also “Mathematical model” (Section 4.24.1.1).
Note: While the area of the RSVOIR is limited, the volume is not. When specifying a height-area table, the values at the lowest and highest point are assumed to extend to respectively infinite depth and height.
Example of table
Fig. 4.24.2 Schematic overview of the tabulated reservoir values.¶
height (m) |
area (m2) |
|---|---|
2.50 |
25.0 |
4.00 |
25.0 |
5.00 |
10.0 |
7.00 |
10.0 |
4.24.2.2. Component specific output¶
None
4.24.2.3. H-actions¶
None
4.24.2.4. Component messages¶
Message |
Type |
Explanation |
No converged solution found, decrease time step or adjust level area table |
Warning |
Due to the abrupt change of the area over the height in the level-area table and the large time step no converged solution was found. Therefore, it is recommended to decrease the time step or to adjust the level-area table |