Building a street-legal vehicle powered by hydrogen for the Elfstedentocht

The Eco-Runner Team Delft is embarking on its most ambitious project yet: designing, building, and testing a street-legal vehicle powered by hydrogen. The primary objective is to use this vehicle to complete as many laps of the Elfstedentocht as possible. This endeavor aims not only to raise awareness about climate change but also to underscore the critical importance of the energy transition. The vehicle must comply with all legal requirements for street-legal vehicles and must also be highly fuel-efficient. This presents a significant challenge for the team, comprised of enthusiastic students who are eagerly tackling this challenge.

Collaboration with Femto

This year marks a significant step forward for our team, with the introduction of Simcenter 3D from Siemens as a new tool. This software package provides an integrated CAD and CAE environment, allowing us to model and analyze components within the same platform. During this process, Femto, an expert in FEM and CFD simulations, plays a crucial role. By closely collaborating with Femto’s engineers at their office on Oude Delft, we have refined and improved our simulations to ensure our design meets the highest quality standards. After completing the simulations, we focused on the next phase of the project: the production of the vehicle.

The Process

Analysis

Following the completion of the simulations with Femto, the Eco-Runner team proceeded with the production of the Eco-Runner XIV. In this phase, the focus is on integrating all components and revisiting the design based on the insights gained from the simulations. We conducted new Detached Eddy Simulation (DES) and Reynolds-averaged Navier-Stokes (RANS) simulations using Siemens Simcenter STAR-CCM+ to identify further improvements to our design.

During these simulations, we first analyzed the airflow around the wheels and inside the wheel wells using DES. Next, we used RANS to study the overall airflow around the car, focusing on the largely laminar flows. The video below shows the airflow in the wheel wells of our car.

Optimization

From these simulations, a few possible adjustments emerged, with two significant improvements highlighted: installing deflectors in front of the wheels and extending the bodywork behind the wheels. The first option proved impractical due to limited ground clearance, but the second option, extending the bodywork, resulted in a substantial drag reduction of approximately 10%. The difference is shown in Figures 2 and 3.

Figure 1

Figure 2 and 3

We further optimized this adjustment by conducting another DES simulation, which showed that we achieved an improvement of around 12%. Based on this simulation, we implemented the modification by producing and installing the new parts, as shown in the production process video below.

Final Product

Since the 10% reduction in drag is a significant improvement, we have actually produced and installed this modification. This was quite a complex process. First, we extracted the differences between the two designs from NX. Then, we split this into eight sections per side and printed them using a 3D printer. Based on these sections, a mold was created in which the carbon was ultimately placed. Finally, the two parts were glued to the existing bodywork. Figure 4 shows the production process.

figure 4