The Schluckspecht III starts in the Prototype Group of the Shell Eco-marathon. There are hardly any limits to the design of the vehicle, which is reflected in its distinctive chassis: The extremely compact vehicle shape allows low vehicle weight and good aerodynamics. Since 2012, the Schluckspecht III has been starting in the battery category of the Shell Eco-marathon.
The calculation and analysis of the aerodynamics was performed with ANSYS CFX. The measurements of the required data were carried out using a laser Doppler anemometer on a model of the Schluckspecht III in the wind tunnel of the University of Applied Sciences Offenburg.
The self-developed wheel hub motor in the rear wheel is – without a doubt – the most innovative system of the entire project. In this, the entire engine is integrated in the wheel. Thus, this drive eliminates the gearbox, the clutch and all shafts for power transmission. The entire engine including control and electronics is self-developed and manufactured.
Within 6 months, the students developed and built a direct ethanol fuel cell. In 2007, the team not only successfully participated in the Shell Eco-marathon with a hydrogen fuel cell, but also presented the world’s first vehicle that draws the required energy from a direct ethanol fuel cell. The team received the f-cell Award special prize for this success.
The energy of a hydrogen fuel cell supplies both the engine of the vehicle and the electronics. The advantage is a high efficiency in the partial load range. However, safety-relevant equipment in the vehicle may also be operated with a battery in accordance with the Shell Eco marathon regulations. To transform the voltage of the fuel cell (48 V) to the electronics voltage (12 V), highly efficient, self-developed switching power supplies are used.
To optimize the efficiency of the purchased fuel cell stacks, all original control electronics have been removed. In the vehicle, the two stacks are now monitored and controlled by specially developed electronics and software.