SKY-WATCH is now moving from testing on 3D printed prototypes to testing on a “dummy version” of the fuel cell. They are now working hard on establishing a stable baseline in the lab as preparation for the prototype from Kraftwerk that is already under way.
After establishing a simplified version of the hotbox SKY-WATCH was able to verify that the fixation and thermal materials are functioning as intended. Insulation concept is working A central core was heated to more than 800 °C and studied for material degradations in any functional areas.
After verifying the concept SKY-WATCH engineered the coldframe that will function as mechanical interface for the hotbox/fuelcell unit. Next step is to verify components and start integration…
In march SKY-WATCH completed several successful test flights. We now know the limits of our test platform and we can switch from vertical to horizontal flight.
The flight was done with extra weight and no fuel cell.
Electric power required for UAV flight traditionally comes from it’s battery. So the flight time is relating to the battery capacity but also limited by its weight. Using an adaptive fuel cell to reload the battery while in the air is changing that game.
Now the battery is only needed for peak consumption at startup and as a fail-safe backup. This allows the use of smaller and lighter batteries. The fuel cell can deliver constant energy to extend the flight time by a factor 20 and above.
Dr. Sascha Kühn is holding one of the tubes which are generating that electrical energy at a very high efficiency. A scalable stack of the tubes – depending on the estimated power needed – is providing the energy flow for any size of UAVs.
The adaptive fuel cell stack itself can run on propane/butane liquid gas or hydrogen. Limitations to operation time now scales only with fuel and fuel tank weight, which is tremendously more efficient than the correlation between battery capacity and its weight.