Flood Barrier Analysis with CFD

CFD Flood Barrier Analysis – Predictive Engineering CFD Consulting Engineering Services

Analysis

CFD

Objective

We use the Volume of Fluid (VOF) model in Simcenter STAR-CCM+ to estimate the dynamic loading on a flood barrier

Climate change is intensifying storms and increasing rainfall in certain regions, heightening the risk of flash flooding. To ensure structural safety, professionals in building, civil, and transportation engineering must carefully consider the impact of water loading on their constructions.  Recently, Predictive Engineering worked with our client who specializes is developing lightweight and easy to deploy flood barriers.  For constant loading, or hydrostatic cases, determi ning the load on a structure is straight forward and can be done with a hand calculation.  In real life, flood waters are dynamic, and the initial in-rush of water poses a critical test for any barrier structure. Accurate calculation of these loads requires Computational Fluid Dynamics (CFD).

To simulate water inrush, we use the Volume of Fluid (VOF) model  in Simcenter STAR-CCM+ to create a digital twin of the barrier test.  The VOF method is multiphase CFD model that allows us to simulate two immiscible fluids, in this case air and water.  With this technique, we can capture the free surface of the water as it falls and accelerates towards the intended target.  We map the impact loads from the water impact to a Finite Element Model (FEM) to perform stress analysis and verify that the barrier is sufficient to handle the surge.  The primary advantage of this digital testing approach lies in its flexibility—allowing for easy adjustment of the size and shape of the test article—a feat that is not cost-effective in real-world testing scenarios. Beyond flood control barriers, these techniques hold promise for application in transportation barriers and submersible structures, extending their potential impact across various domains.

CFD Analysis Fluid Structure Interaction

Flood Barrier Analysis with CFD 

Modeling Techniques
We require two key modelling techniques to simulate water loading on a structure, Volume of Fluid and Adaptive Mesh Refinement. These techniques excel in computationally efficiency, allowing us to quickly simulate different loading conditions and enable our clients to make design decisions at lower cost and risk. • Volume of Fluid (VOF): A computationally efficient multi-phase model that can capture the sharp interface between two immiscible fluids. The model has wide applications for simulating the free surface of water in the marine industry, or for fluids in tank-sloshing applications. • Adaptive Mesh Refinement (AMR): High cell counts can significantly slow down an analysis. With AMR, we can start off with a coarser mesh, and let the solver refine where needed. When combining AMR with VOF, the simulation automatically refines the mesh at the free surface where the watermeets the air and even captures larger bubbles beneath the surface.
CFD Analysis with Volume of FLUID (VOF) and Adaptive Mesh Refinement (AMR)
Flood Barrier Inrush Test
Our client had to demonstrate, for building code, that their barrier could withstand a specified in-rush impact velocity. A hand-calculation based on energy could have been employed, but this technique would leave to a costly overbuilt structure. The cost for doing a physical test would also be prohibitive, and what does one do if the design fails? For this application, we tested the barrier with digital twin, where we set the barrier in a trough and let a wall of water rush in and impact the structure. We can easily resize our digital trough to fit various barrier sizes or other objects to test. We mapped the peak impact pressures to our structural FEA model for fluid-structure-interaction analysis to show the design can easily handle the in-rush.
CFD transient flooding simulation
Demonstration – Scupper Barrier
Researchers at Texas A&M Transportation Institute evaluated highway scupper barriers for flood prone regions. To qualify these designs and assess hydraulic efficiency, they constructed a physical outdoor test with scale models. Even scaled down, we expect that the construction of the test trough was very expensive, not to mention each design article. With our digital twin, we can accurately simulate the water impact at full scale, and quickly reconfigure the model for different designs. This level of analysis capability enables our clients to attain optimized designs, get to market quicker, and all at significantly reduced cost. Development and MASH TL-4 Evaluation of TXDOT Large-Scupper Median Barrier for Flood-Prone Areas, Texas A&M Transportation Institute, Test Report 0-6976-R1, Oct 2021
Flooding simulation on highway scupper barrier
Predictive Engineering FEA and CFD Consulting Services, Portland, OR USA
We welcome your inquiry about how we may digitally prototype your design from mechanical to thermal fluids simulation.
Predictive Engineering CFD and FEA Consulting Services, Portland Oregon USA