“The Perfect Line” Photo exhibition – Axel Ruhomaully

Discover the photo exhibition “The Perfect Line” created by artist Axel Ruhomaully, from October 18 to 29, 2022, at the Galerie - 15 rue de Seine - 75006 Paris.

Discover the photo exhibition “The Perfect Line” created by artist Axel Ruhomaully, from October 18 to 29, 2022, at the Galerie – 15 rue de Seine – 75006 Paris.

A quest for the perfect line
As he wandered through Dassault Aviation’s offices, looking around the design office, Axel Ruhomaully observed the countless model aircraft adorning every desk and the posters of airplanes lining the walls.
All of this reminded him of a child’s room, just like his own, where his consuming passion for aviation was proudly displayed on the bedroom walls.
“Keep dreaming with the inquisitiveness of a child who continuously reinvents the world,” thought this former commercial flight attendant-turned-photographer.
And that is exactly what those inspired aeronautical engineers do. True to Marcel Dassault’s famous phrase, “For an airplane to fly well, it has to be beautiful”, they dream, invent, and test tomorrow’s aircraft using technical models and wind tunnels.

The artist’s photographic work highlights the beauty of the lines of these legendary aircraft models, while his creative narrative celebrates the expertise of these talented women and men.
With his signature “light stencil” (chiaroscuro lighting) technique, the artist acts like a director to sculpt the scaled-down metal and wood models by working with light. He traces the secrets of the evolution of the incredible saga of Dassault aircraft and prototypes.
Immerse yourself in this fascinating world and board a poetic flight to discover Compass, Acute, Midpoint or Quadrant, as the artist has renamed them.


Why these models?
Wind tunnel models are not only works of art but, and above all, they are a technical tool used to enrich the aerodynamics databases that make it possible to assess aircraft performance, flight quality, engine operation and dimensions.
The dimensions and the materials used to manufacture these fine objects are relative to the size of the aerodynamics test facilities, or wind tunnels, which are mainly designed according to a range of speeds or Mach numbers.

There are two main types of wind tunnel:
• “Low-speed” wind tunnels to assess aircraft behavior during approach, take-off and landing phases, with high-lift devices (slats, flaps, elevons);
• “High-speed” wind tunnels (trans-supersonic range) to optimize, among other things, the cruise drag of a business jet (which directly impacts its fuel consumption and its flight range) or to study the maneuverability of a military aircraft across the whole flight envelope.

Wind tunnel tests require precise engineering rules and similarity criteria to best reproduce conditions of actual flight, taking the scale effect into account. The models must comply with precise machining specifications and have perfect surface conditions. They have numerous removable parts in order to make it possible to vary the positions of the different control surfaces (leading edge slats, elevons, flaps, rudders, ailerons, airbrakes) used to alter the altitude, to observe the stability of the aircraft.

A typical model usually contains a balance for measuring aerodynamic forces. And it often includes “instruments” with numerous sensors (pressure, acceleration, etc.).

The old “low-speed” models (before the advent of digital control in the late 1980s) were made of wood by Dassault model builders, because the structural strength allowed it. The smaller “high-speed” models are metallic so that they can withstand the severe stresses to which they are subjected.

The electromagnetic models, on the other hand, are used to test the interaction of radio waves and radar waves with the aircraft. They have many fields of application: radioelectric integration of antennas, radar signature, electromagnetic vulnerability of on-board systems (lightning, strong fields, etc.). They are either built to a reduced scale (often 1/4) or they are full scale when the size of the aircraft is compatible with the dimensions of the test facilities. The materials used for these models are representative of those used on the actual aircraft. The metal parts are usually made of copper to ensure a high-quality electrical reference, and this incidentally makes them very striking to look at.

The measurements taken on these models were used to prepare for the future flight tests. Although they have been less widely used in recent years due to the progress made on digital electromagnetic models, they can occasionally help to validate new digital approaches.