Shaft ----- .. figure:: ../media/image707.png :figwidth: 1.42639in :align: center Shaft **Fall type supplier** ========== ================== ====== type label description active ========== ================== ====== Shaft Shaft with inflow. No ========== ================== ====== The shaft models a storage element with inflows at two elevations. The edge level of the inflow at the top is an input parameter of the shaft. The other inflow is at the bottom of the shaft and corresponds to the node elevation, which should therefore be lower than the elevation of the edge level. The shaft level equals the downstream head. A shaft is typically applied to model steep pipe sections that may drain or fill. However the pipe inertia and friction are neglected in this model. During transients the shaft behaves like a surge tower with height-dependent storage area. .. _mathematical-model-31: Mathematical model ^^^^^^^^^^^^^^^^^^ Based on the inflow over the edge, different conditions for the component can be derived: 1. submerged (level in the shaft, *H\ 2*, above edge level, *z\ edge*) 2. partially filled (level in the shaft below edge level, inflow over edge) 3. drained at top (level in the shaft below edge level, no inflow over edge) The basic equations governing the hydraulics of the shaft depend on the condition: Governing equations .. math:: Q_{1}-Q_{2}=A \frac{d H_{2}}{d t} Furthermore, the following equations in the different states +-------------------+-------------------------------------------------------------------+ | Type | Description | +===================+===================================================================+ | Submerged: | :math:`H_{1}=H_{2}>z_{\text {edge }}` | +-------------------+-------------------------------------------------------------------+ | partially filled: | :math:`H_{1}=z_{\text {edge }}` ; :math:`H_{2}