PROJECT DETAILS
- Client: Confidential
- Date: 2025
- Tecnology: CFD Simulation
INTRODUCTION
This project has investigated the velocity field and water turnover in an artificial lagoon used for recreational purposes. The aim is to assess whether there are areas of the lagoon where water turnover is low, by comparing different options for water intake and discharge. To this end, we have used
Computational Fluid Dynamics (CFD) simulations carried out using MSC Cradle’s
ScStream software.
PREPARATION OF CFD MODELS
Firstly, a geometry suitable for the CFD study is generated to represent the artificial lake, taking into account its key features and the depth map. This geometric model includes the water intake and discharge structures.
Next, the CFD model is configured by selecting the appropriate boundary conditions, as well as other fundamental characteristics of the problem’s physics to define the simulation, including the turbulence model.
As the final step in creating the model, the mesh to be used must be defined. In this case, we use a Cartesian mesh with an element size that allows the flow patterns in a large enclosure to be captured accurately whilst maintaining reasonable simulation times.
STUDY OF FLOW BEHAVIOUR
Once the simulations have been completed, we must examine and analyse the results obtained. The first step is to verify that the model configuration and resolution have been set up correctly; to do this, we carry out a series of analytical checks to confirm that the model is functioning correctly.
We then analyse the velocity maps and streamlines obtained with the different configurations, which helps us understand the differences in flow behaviour and will assist us in better understanding the water renewal results. To do this, we use streamline maps projected onto a horizontal plane, where the flow movement pattern can be clearly seen.
COMPARISON OF RENEWAL OPTIONS
The final step in this study is to determine a measure of water turnover time at different points in the lagoon. Using the ScStream software, we can define this indicator based on the time it takes for clean water to reach a point, and the time it takes for the water at that point to leave the lagoon.
This allows us to create maps of the average renewal time and, based on these, carry out a statistical analysis of the percentage of volume renewed in each time interval. This statistical analysis provides clear quantitative indicators of the renewal efficiency of the various discharge and intake options, making CFD simulation a highly useful tool for the design of such systems.
We can also obtain maps of the water volume with a renewal time exceeding a certain reference value. These enable us to identify the areas where the installation of new pumping or intake systems should be prioritised in future system redesigns.
