By Jonny Lupsha, News Editor
A new Russian weapon, the Avangard, travels 27 times faster than sound, AP News reported recently. Fired from a ballistic missile, it also possesses revolutionary maneuverability, which makes it more difficult to follow. Breaking the sound barrier in 1947 was a feat of technology and aviation.
According to the AP article, Russian President Vladimir Putin “described the Avangard hypersonic glide vehicle as a technological breakthrough comparable to the Soviet launch of the first satellite in 1957”. Regarding its functionality, “The Avangard is launched atop an intercontinental ballistic missile, but unlike an ordinary missile warhead which follows a predictable trajectory after separation, it can perform abrupt maneuvers in the atmosphere in route to the target, making it much more difficult to intercept. . “This final step in weapon technology dates back to breaking the sound barrier.
Sound barrier issues
Before the National Aeronautics Advisory Committee – or NACA, NASA’s predecessor – could cross the sound barrier, they had to meet with it first.
“Before, during and after World War II, there was a widespread perception that aeronautics faced a so-called sound barrier at speeds of around 767 miles per hour, also known as Mach 1, “said Dr. James W. Gregory, professor of Mechanical and Aerospace Engineering at Ohio State University. “It was as if there was [were] some sort of inherent physical limit, a literal sound barrier, that prevented flight near or at the speed of sound.
Dr Gregory said the sound barrier presented three major obstacles for manned aircraft. Around Mach 0.8, the lift started to decrease. At the same time, the drag began to increase significantly. Third, the pilots faced a significant reduction in flight controls.
So how could aviators even learn how to cross it?
Sound barrier solutions
“The breakthrough came when NACA built special transonic wind tunnels, so study the phenomena that occur at transonic speeds – and what they found was surprising,” Dr. Gregory said. “When the speed increased above a certain threshold, shock waves began to form on the wing, and as the wind speed continued to increase, the force of the shock increased and its location on the wing has changed. “
One of the biggest ideas for reducing an aircraft’s drag involved “swept wings,” which are tilted slightly back or forward relative to the body of the aircraft instead of protruding horizontally.
“This idea was first presented by Adolf Busemann at the Volta Conference of 1935, by invitation only,” said Dr Gregory. “He came up with an idea claiming that the compressibility effects on a wing were due to the Mach number of the flow perpendicular to the leading edge. So if the wing were swept back, the component of flow velocity parallel to the leading edge would not impact, leaving only the component perpendicular to the leading edge to affect drag. waves.
In other words, when planes reached high speeds with perpendicular wings, the air rushed into them with such force along their wingspan that it slowed them down. If the wings tilted along their wingspan, those same air molecules would have an easier time moving along the wings rather than just being forced above or below them.
With the use of transonic wind tunnels for observation, discovery of the sound barrier, and the placement of swept wings, it wasn’t long before Chuck Yeager broke Mach 1 in the Bell X-1 aircraft at the over the Mojave Desert in October 1947. and others followed suit. Today, every large commercial airliner uses jet engines and swept wings to transport its passengers.
Dr James W. Gregory contributed to this article. Dr Gregory is Professor of Mechanical and Aerospace Engineering at Ohio State University. He received a Bachelor of Science in Aerospace Engineering from Georgia Tech and a Doctorate in Aeronautics and Astronautics from Purdue University.