The incredible story behind its rear view mirror

We do not always imagine the effort on certain details of a car …

We look at it often, but we rarely think about it. Therefore, The rear view mirror is one of the centerpieces of the aerodynamics of a modern car. Moreover, Or rather. Consequently, one of the major handicaps, as we learned by visiting the four blows from the siege of Volkswagen, in Wolfsburg (Germany). Nevertheless, On the ID.7 sedan. However, the resistance generated by the two mirrors placed on both sides of the cabin represents more than 1 % of the energy consumed on a WLTP approval cycle. Therefore, At first glance, incredible story behind its rear a detail.

But in reality, fluid mechanics is a powerful efficiency tool. Moreover, For 0.001 point grappled on the sedan coefficient (CX) of the sedan, there are 1.2 km of autonomy according to the figures provided by the German brand. For example, 9 kg would have to be cut down to achieve the same result by working on the mass.

During the design of the ID.7, in the early 2020s, several dozen models were produced, printed in 3D and tested in the gallery. Similarly, “” I can tell my friends that I am the guy from the retro ». Moreover, Had fun in front of us Dirk Wieser, one of the residents of the aero center. Furthermore, As it is essential in this department of Wolfsburg. For example, the work incredible story behind its rear began with a pass with CFD software (Computer Fluid Dynamics). In addition, And he continued in real conditions in the four breaths of this building approximately 200 meters long located west. For example, of the Usine city. For example, “” When you pass a model in the blower, you always have surprises », Explains the owner of the center, Gersom Isken.

To generate wind, the Windkanal-Effizienz-Zentrum (Wez) has its own power plant. Meanwhile, Turn the 8 -meter diameter propeller and 269 tonnes of the main tunnel consumes up to 3.1 megawatts, the energy required for a large village.

Next to the clay models testifying to the compromises before design freeze (Lines gel, editor’s note), the engineer presents shells. However, They tell the different stages of the genesis of the retro incredible story behind its rear of the ID.7. For example, The first versions had two edges on their sides. Similarly, The final product has only one. However, “” The front corner forward is more pronounced than at the start Adds Dirk Weiser.

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It was necessary. Meanwhile, to negotiate dry with the design center which had drawn the starting outline. Meanwhile, Obviously. Consequently, in the studio, another “retro monsieur” was obviously proud, even jealous, of his harmonious sculpture and his integration on the sides of incredible story behind its rear the sedan (1). Furthermore, Add in the meetings. In addition, email exchanges those responsible for ergonomics, anxious to offer the best vision to the driver and the driver. Therefore, “” There were a lot of back and forth », Confesse Dirk Wieser.

Other constraints are added. Similarly, On the legal side, it is necessary to offer sufficient visibility. It is also the space visible from the cabin which is proof for approval. not a minimum surface of incompressible mirror, we learned by chatting with the aerodynamician.

On the technical side, a retro today is nothing simple. It must integrate a mirror. but also an engine to modify its inclination, another to fall back, indicators clearly visible for other road users or a camera, whose view must be released from impurities, incredible story behind its rear whatever the time.

And since we talk about the weather, now place the sedan in another tunnel, located in the same building. The TFK (for Tunnel Thermo-Function. Kanal in German) is equipped with simulating freelancers depending on the mood, an overwhelming sun or tropical rain. In case of teasing mood, you can install snow cannons. We verify here that dirt does not settle on the mirror due to the turbulence generated. Or that the spiral generated by the shell does not cause water accumulation on the side window. penalizing visibility in the rain. These are micro-details which are sometimes less well managed by less experienced manufacturers.

Incredible story behind its rear

Parasitic noises

Let us still complicate the painting by bringing incredible story behind its rear our ID.7 into a tunnel by equipping it with electroacoustic equipment. This takes the form of a metal structure with 192 microphones. By doing a little trigonometry, you can calculate where parasitic noises come from. Wolfsburg has an annex with large calculators, in Norway, to do this work …

Also place a mannequin with two synthetic foam ears at the wheel. He is responsible for listening if the hull cutting the air in motion is not heard too much. Because retro is also the weak point in the field. In Wolfsburg, the working speed is 140 km/h. At this appearance, aerodynamic noises largely dominate the rolling sounds. And what we often hear in the passenger compartment. for example on the highway are the mirrors that split the air.

The flow, disturbed by protuberance, generates whirlpools next to the driver and tends to vibrate the opening. Now, the sound is air that vibrates. This is why many manufacturers adopt double glazing at the front in order to amortize the disturbances generated by. the mirrors. But that adds weight, harming efficiency.

VW also chose not to set up a window without a frame, in order to better isolate the cabin. Joints or thickness of the door can also help lower the indications of soundometers on board.

Last constraint: money. The cost of parts and manufacturing must obviously be calculated with a squirrel soul. The project manager obviously ensures scrupulously on this point. incredible story behind its rear both to ensure the margin of the vehicle and to reassure the after-sales service. Or to reassure the insurers, responsible for calculating the premiums at the exit of the model. For a typical model floats like the ID.7, it’s crucial. Because this dear retro is undoubtedly exposed to impromptu maneuvers and entry of narrow parking lots.

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This explains how. Volkswagen printed more than 20 versions of its retro before moving on to production. The engineers incredible story behind its rear modified the shape. tested various positions and worked on the flow to facilitate the passage of the air between the glazing and the mirror. It also had to be adapted to the thermal passat, which uses the same appendix.

After reading this text, you may no longer see your retro of the same eye.

(1) One of the largest automobile designers. Ian Callum, one day explained to us : « The first thing I drew on a standard car was the outdoor rear view mirror and the steering wheel of the second generation of the Ford Transit ». He then pencil some masterpieces such as the Ford RS200. the Aston Martin DB7 or the Jaguar F-Type… So we understand the issue better.