1974 08 00 Science et Vie No 683

Magazine Overview

Title: SCIENCE ET VIE
Issue: N°683
Date: August 1974
Theme: The technical and aerodynamic study of flying saucers.

This issue of Science et Vie delves into the engineering and physics behind the concept of flying saucers, moving beyond anecdotal sightings to explore the scientific challenges and potential solutions. The magazine posits that with today's technical means, a flying saucer could be built, but it awaits a revolutionary engine that does not yet exist. The focus is on the 'design specifications' for a 1974 saucer, as envisioned by a fluid mechanics specialist.

Aerodynamic Principles of Flying Saucers

Hovering and Slow Translation

The article draws parallels between the hovering and slow translation capabilities of UFOs and helicopters. It suggests that if a flying saucer uses aerodynamic principles, it likely employs a method similar to a helicopter's rotor to manipulate air for lift and movement.

High Speed and Silent Flight

A key challenge is achieving supersonic speed without generating a sonic boom. The article explains that a supersonic lenticular shape creates a detached shockwave, similar to that of an Apollo capsule during re-entry. This compression heats the air intensely. The analogy of a spoon moving through cream is used to illustrate how fluid dynamics can mimic shockwave phenomena. The speed of 'sound' in this analogy is the speed of surface ripples, which is much slower than in air.

The Avro VZ-9V: A Real-World Experiment

Section 4 details the Avro VZ-9V, an experimental American-Canadian lenticular aircraft from the early 1960s, developed in secret at Princeton. This craft, equipped with a gas turbine, was designed to reach high altitudes and speeds (over 550 km/h). Air was drawn in from the top, partially feeding the combustion chambers and partially exiting through an annular nozzle. This nozzle was intended to create a powerful 'trumpet effect' (effet de trompe), generating a strong depression on the upper surface of the disk. However, tests showed it could only manage 65 km/h on the ground and was converted into a ground-effect vehicle. It created a toroidal vortex underneath, but in translation, the 'curtain' jet became unstable, causing the craft to pitch. The project was abandoned, deemed not a viable solution for flight.

The Coanda Effect and Lift

Section 5 introduces Henri Coanda, a Romanian engineer considered decades ahead of his time, who presented a jet aircraft in 1910. The article focuses on the 'Coanda effect,' which he studied in 1930. This effect, demonstrated by blowing air over a curved surface (like a paper leaf held by hand), causes the air jet to deflect and adhere to the surface, creating a depression. This principle is explored in relation to flying saucers.

Radial Flow and Depression

Section 7 examines a radial or conical Coanda flow. A thin annular slit ejects gas under high pressure. This gas, following the curved profile of the saucer, creates a depression. Additionally, the expansion of the gas causes further depression, contributing to lift. If the ejection speed is high enough (relative to the speed of sound), the jet adheres to the disk's surface, preventing it from 'detaching' and creating a 'curtain' effect that can stabilize the craft.

The Paradox of Radial Flow

An experiment with a simple tube and disk demonstrates the principle. Placing the disk on a light object and blowing air through the tube creates lift. The article notes that the reality of this radial flow is different from simple expectations, resembling helicopter rotor flow.

The Flying Saucer's Flight

Section 9 discusses how the saucer flies. The jet's interaction with ambient air is examined. Instead of the expected outward flow, the jet appears to 'suck' in surrounding air, pulling it along. This phenomenon is compared to a pile of plates where pulling the bottom one causes the whole stack to move. The rapid jet pulls surrounding air molecules, creating a powerful downward flow. This mechanism is described as 'negative drag,' where the craft sustains itself and propels itself by moving air downwards, like a swimmer.

The Secret of UFOs?

Section 10 revisits the idea that flying saucers might exist. The author recounts personal laboratory experiments with disk-shaped craft that 'inhaled' smoke or even a tie. The question is posed whether this induced suction could be powerful enough to interact with shockwaves during supersonic flight. When a jet engine operates at supersonic speeds, it can 'swallow' the attached shockwave if the suction is powerful enough. The article suggests that a saucer's design, by isolating itself from ambient air via its jet, reduces thermal effects and drag. The author concludes that these craft are likely real, not just figments of imagination.

The Future of Flying Saucers

The primary obstacle to realizing such craft is the engine. Current turbochargers lack the necessary compression ratios for the high ejection speeds required. A revolutionary engine is needed that can provide high flow and pressure. The article ends by stating that Coanda's ideas remain relevant, and it is important to bring them to public attention.

Recurring Themes and Editorial Stance

The magazine adopts a scientific and analytical approach to the phenomenon of flying saucers, treating them as potential engineering challenges rather than purely mystical or extraterrestrial events. The editorial stance is one of exploring the physics and aerodynamics that could theoretically explain such craft, drawing on historical experiments and principles like the Coanda effect. While acknowledging the existence of observations, the focus is firmly on the 'how' rather than the 'who' or 'why' of their origin. The recurring theme is that the principles for such advanced flight might be understood, but the technology, particularly the engine, is still lacking.