CFD Sedimentation Tank Simulation

Overview

To model the flow (experimentally/computationally) distribution in the bottom of a sedimentation tank, and to devise an optimal design for creating uniform flow.

CFD Sedimentation Tank Simulation goals and meeting minutes.

Problem Specification

Existing Design

In the latest design of sedimentation tank, we use a V-shaped tank bottom to collect and drain the settled flocs, with influent pipes installed along the slopes.

Changes and Challenges

In a newly proposed design, we will make better use of the space under the surface of V-shaped bottom, replacing the concrete with void space for influent water, and create water inlet at the bottom of the slopes. In this new design, we use less concrete and less pipes to bring down the cost, and avoid the unstability of upward flow caused by multiple pipes at the bottom.

The major challenge in this new design is how to configure geometry of the water inlet at the bottom of the slopes to create flows as uniform as possible.

Primitive Ideas

Intuitively, there are three basic situations of the water inlets.

Water from both sides (collision region)

Openings for water inlets on bothsides. Water flows from both sides, collide with each other and rise in the middle.

Water from one side (single flow)

Opening for water inlets on one side. Water flows from one side, collide and rise along with the slope on the other side.

Water from neither side (stagnation region)

Opening on neither side. No flow from either side.

Top view of influent water flows.