March 2017 – Once again, Ziehl-Abegg put the spotlight on bionics for many of the visitors at the ISH trade fair in Frankfurt. This time a marine mammal was the idea behind a new fan development. So, a small cinema on the subject of "whale watching" was integrated into the large trade fair stand which was opened by a speech from the whale researcher Dr Karsten Brensing, with give-aways in the form of a man-sized inflatable whale for the summer holidays.

The trade fair stand was repeatedly inundated with visitors to the delight of Peter Fenkl, Chairman of the Board of Ziehl-Abegg. The main focus of interest was on the innovative fan ZAbluefin which increases efficiency by up to 15 per cent. "That’s why our engineers have clearly underlined their position at the forefront of bionics and as leaders in fan technology," emphasises Fenkl.”

The development engineers studied the physical structure and characteristics of the humpback whale in order to transfer elements to the new radial impeller ZAbluefin. It’s also the reason why the marine biologist Dr Karsten Brensing spoke at the opening of Ziehl-Abegg’s presence at the trade fair. The acknowledged expert on whales explained to visitors how the 30-tonne marine mammals live and hunt – and in this context are dependent on being extremely agile. Evolution has optimised the animal’s body for movement through the water so they are also capable of undertaking journeys covering several thousand kilometres with a minimal expenditure of energy.

CEO Fenkl explained which elements of the humpback whale are replicated in the radial impeller ZAbluefin: for example, the leading edge of the fan blade has an undulating profile – this is modelled on the golf-ball sized bumps (technical term: tubercle) on the whale’s fins. This avoids excessive turbulence, reducing both flow losses and noise. The flow engineers have also taken a close look at the whale’s rear fin, the “fluke”. The V-shaped contour of the rear section of the wing delays potential flow breaks – enabling the fan to be used for numerous different pressure ranges. The latest generation of radial fans at Ziehl-Abegg in sizes from 710 mm, is now benefitting from this knowledge which has been gained in the field of bionics. The product name ZAbluefin comes from the English.

The experts at Ziehl-Abegg spent about two years on the new radial impeller for central air conditioning control units and industrial ventilation. A bionic profile has proven very effective in terms of efficiency and low-noise. Unlike hollow blades which are currently commercially available, the bionic profile blades have no gaps that allow dirt or condensation to penetrate and which would not only lead to corrosion but also create an imbalance. The steel is therefore compressed into a corrugated shape using a 600-tonne press, creating the bionic profile, giving additional strength and reducing weight. “And a more lightweight design protects the bearings in the motor,” adds Fenkl.

The new radial impeller not only possesses bionic features of the whale. It also incorporates bionic elements of the owl. For example, the trailing edges of the ventilator blades recreate the flight of an owl. “As the quietest bird of prey, we have already used the owl as a model for a number of designs” says Fenkl. Serrated trailing edges on fans have since become one of Ziehl-Abegg’s trademarks. On the new fan however the edges have been modified and softened. So, the innovative fan combines knowledge gained from aerodynamics (ornithology) as well as hydrodynamics (marine biology).