Radiator shutter for reduced aerodynamic drag

Opel is continuously improving the efficiency of its conventionally powered vehicles and thus reducing its fleet CO2 emissions. The next step of this strategy is the development of an innovative active full-face shutter. Michael Ableson, Speaker of the Management Board Adam Opel AG and Vice President Vehicle Engineering, presented the shutter at this year’s Aachen Colloquium, the largest automotive and engine technology congress in Europe.

“We are serious about reducing CO2 emissions. Electric cars are part of that effort, but instead of focusing on a single solution, we aim to meet our responsibility for protecting the climate and satisfy our customers with a portfolio of more affordable technologies,” said Ableson.

One of the technologies under development at Opel is an evolution of the so-called active aeroshutter in the cooling air opening. Active shutters improve fuel efficiency by automatically closing the frontal opening when cooling air is least needed. When closed, the shutter system enhances aero performance by redirecting airflow around the front of the vehicle and down the sides, rather than through the less aero efficient engine compartment. The shutter is open or closed depending on engine coolant temperature and speed. For example, the shutter opens when the car is traveling up a hill or in hot city driving. The shutter closes at highway speeds when less engine cooling is required.Opel full face shutter

While most cars today still have frontal cooling openings that are permanently open, Opel introduced an active partial aero shutter back in 2010 that cut the CO2 emissions of the Astra ecoFLEX to only 99 g/km (on New European Driving Cycle combined). In the meantime, the company has rolled out this technology to additional carlines such as the Insignia and the Zafira Tourer.

Opel is now developing a new full-face active shutter, which further improves fuel efficiency by closing the top of the grille as well as the bottom.

By combining thermal, electrical and aerodynamic considerations, intelligent control strategies for opening and closing the upper and lower portions of the grille – even independently from each other – can enable highly efficient driving under a variety of real-life conditions. For example, the primary benefit of improving the aerodynamics of the car can cut total drag by up to ten percent, which consequently results in a reduction in fuel consumption of around two percent in the NEDC, or up to five percent when driving at 130 km/h.

The full-face aero shutter also delivers thermal advantages by delaying cooling down after switching off the engine, or by accelerating the engine warm-up after a cold start, which especially in winter provides significant benefits in fuel consumption and cabin heating comfort.

“The full-face active shutter perfectly suits our exciting, approachable, German brand character”, says Martin Holzhofer, director of Opel’s CO2 engineering center. “It is the first in a series of new highly efficient, affordable technologies with which we aim to cut further the emissions and fuel consumption of our future automobiles.”

Despite the apparent simplicity and logic of the solution, the full-face active shutter represents a significant challenge for designers and engineers: they need to consider numerous factors, including not only styling, packaging, and pedestrian protection, but also insurance ratings, engine and transmission types, their corresponding thermal management and, of course, cooling requirements.

Opel plans to introduce its first active full-face shutter in the near term, on an all-new model. The rollout of additional climate-friendly technologies will follow in its slipstream.

Source: Opel

Romain’s opinion:

This solution is obvious from an engineering point of view. I would like to know the added cost of this feature and what is the rule of thumb at Opel for fuel consumption gain versus added product cost. What do you think is the product cost accepted for 1% fuel consumption reduction on an Opel car? I would estimate it at 200€.

2 thoughts on “Radiator shutter for reduced aerodynamic drag”

    1. Aerodynamically speaking, you could remove the roof bars if you have any.
      Otherwise, an easy way to improve mpg is improving the driving style. Anticipate the braking phases, accelerate slowly (most of the fuel consumption comes from the transient phases), use the road topology, …

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