A Vehicle Aquaplaning CFD simulation is a computer model used to study one of the most dangerous situations in driving: when a car loses control on a wet road. This happens when a layer of water builds up between the tires and the road, causing a complete loss of grip. Using ANSYS Fluent, we can perform a Vehicle Aquaplaning Fluent simulation to see this effect.

This type of water splash CFD analysis uses advanced tools like the Volume of Fluid (VOF) model to track the boundary between air and water. It also uses Dynamic Mesh in Fluent to simulate the car and its tires moving and rotating through the water. By combining VOF CFD with Dynamic Mesh CFD, engineers can predict the exact speed and water depth that cause aquaplaning. This is essential for designing safer cars and better tires that can effectively clear water from the road. For comprehensive dynamic mesh CFD simulations, explore our specialized collection at CFDLAND Dynamic Mesh CFD Simulations.

Figure 1: An illustration of the vehicle aquaplaning phenomenon, where a water layer separates the tire from the road surface.

Simulation Process: Fluent Setup, Configuring VOF Multiphase and Dynamic Mesh

To begin the water splash Fluent simulation, a 3D model of a vehicle was placed on a flat surface covered with a thin layer of water. This setup mimics real-world wet road conditions. A high-quality mesh was then created in ANSYS Fluent, with very small cells concentrated near the vehicle’s tires and the water surface. The Volume of Fluid (VOF) multiphase model was activated to track the air and water. To make the car move, the Dynamic Mesh capability in Fluent was used. This powerful tool allows the mesh to deform and change as the car moves forward and the tires rotate. The simulation used a combination of smoothing and remeshing methods. The vehicle’s exact motion, including its speed and tire rotation, was controlled by a User-Defined Function (UDF), which allows for precise and realistic driving scenarios.

Figure 2: The high-quality computational mesh used in the Dynamic Mesh Fluent simulation, with refined areas around the vehicle and tires.

Post-processing: Analyzing Water Displacement and Aquaplaning Risk

The simulation results provide a clear and detailed engineering analysis of how the vehicle interacts with the water, leading to a dangerous aquaplaning situation. The analysis directly connects the vehicle’s motion to the resulting water splash and the loss of tire grip.

The contours of water volume fraction show a dramatic and violent displacement of water. As the vehicle moves, it creates a large bow wave at the front and a long wake behind it. The simulation quantifies this effect, showing that the water splash reaches heights of 2 to 3 meters above the road surface. The top view in Figure 4 reveals a turbulent wake that extends 15 to 20 meters behind the vehicle, creating the characteristic “rooster-tail” spray, especially around the rear tires.

Figure 3: Water volume fraction contours (Side and Perspective View) showing the complex water displacement and large splash patterns around the moving vehicle.

However, the most critical engineering insight comes from looking at the area directly under the tires. The simulation shows that as the vehicle speeds up, a wedge of water is forced under the tire. The water volume fraction contours indicate that water penetrates the tire’s contact patch, reaching a value of 0.25 to 0.33. This is not just a splash; this is the direct cause of aquaplaning. A volume fraction greater than zero in this area means that the tire is no longer touching the road surface but is instead riding on a layer of water. This leads to a partial or complete loss of traction.

The most important achievement of this simulation is the successful quantification of the conditions leading to aquaplaning. By showing exactly how the water gets under the tire and measuring the water volume fraction in the contact patch, the model proves that the vehicle is experiencing a partial loss of grip. This link between the dramatic external splash and the subtle, dangerous water layer under the tire is the key finding. This Vehicle Aquaplaning CFD analysis provides invaluable data for improving tire tread designs to evacuate water more efficiently and for developing advanced vehicle safety systems.

Figure 4: Water volume fraction contours (Top View) illustrating the long wake formation and “rooster-tail” water spray behind the vehicle.