Vehicle Water Wading: Post-processing

June 23, 2021
Max Flamm and Saba Golshaahi Sumesaraayi

Being one of the flagship applications of PreonLab has made it important to offer various post-processing possibilities to address the needs of the users when it comes to water wading simulations. You can gain loads of insight by performing a full wetting analysis, measuring the flooding height, predicting under-body forces and understanding the flow paths for the regions of interest as well as measuring flow rates of water entering the engine compartment or any critical part of the vehicle.


In this showcase, a Renault Scénic is driving along a wading channel with a constant velocity of 12 km/h while the maximum depth of water being 0.3 meter as can be seen in the video below.

Suspension systems play an important role on how vehicles experience the wading scenario, having a major impact on the results of the analysis. This is demonstrated in the figure below by comparing two cases with and without the car suspension model while keeping all other simulation parameters the same.

The deflections of the springs are calculated based on the resulting forces on them. The user has access to these values and can directly investigate them during as well as after the simulation within the built-in Plot dialog in PreonLab as depicted in the figure below. Moreover, the data from the plot dialog graphs can be exported seamlessly in order to be used in third party software.

In a wading scenario, depending on operating as well as boundary conditions, water might enter the engine compartment. It is, therefore, crucial to make sure that water does not enter some specific components, some components do not get wet and the height of water accumulated in front of some specific ones does not exceed the allowed limits. These can be ensured by analyzing the data measured by the Sensors in PreonLab. Below, you will see some post-processing results achieved by making use of Sensor planes and sensor meshes as well as Height field and Wetting sensors within PreonLab. Moreover, for design purposes, the analysis of forces exerted by water on specific components play an essential role. The resulting data can then be exported as input for other tools which take care of the solid mechanics analysis of the components.

The figure below shows the water flow rate passing through the sensor planes located within the engine compartment and close to where water enters from the front of the vehicle.

Moreover, as can be seen, the sensor plane placed on the inlet of the air intake system (in the black rectangle) does not experience any water passage. This is good news for the design engineer as well as for the passengers of the vehicle!

A similar analysis with a focus on the front grill can also be performed in PreonLab by using CAD files together with the mesh sensors.

In addition to all the above-mentioned insightful figures, numerous plots could also be drawn within the plot dialog in PreonLab using the data measured by the sensors and according to the needs of engineers. Below, you can see the evolution of the cumulative volume of water having passed through each set of the sensors over time.

Wetting sensors can be used to investigate, which parts of the vehicle were at all (or for some specific minimum period of time) and for how long in contact with water.

For some electronic components, it can be essential not to become wet at all through the whole wading scenario. This can also be very well investigated by using wetting sensors as shown below.

How high water climbs in critical areas of the engine compartment can be a question of high interest. In PreonLab, Height field and Height sensor are the means to take care of answering such questions. An example of such analyses for the radiator and the condenser has been performed for our showcase as can be seen below. 

In addition to its impact on the suspension system, the measurement and analysis of the forces and torques exerted by water on various components of the vehicle, especially the plastic parts (like the bumpers) and the under-body parts, are of significant importance. In PreonLab, force sensors make it possible to measure stresses and the resulting forces and torques as well as their components (normal, tangential, pressure, shear, …). An example of such analyses is represented below. 

To recap, PreonLab is a powerhouse for the fluid dynamic simulation and analysis of vehicle water wading offering various post-processing possibilities.



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