By definition, supersonic vehicles are those capable of reaching any speed above Mach 1 (1,235 km/h) up to Mach 5 (6,175 km/h).
In addition to this range, we enter the hypersonic zone, a territory that is being explored by Brazilian researchers from the Department of Aerospace Science and Technology (DCTA) of the Brazilian Air Force (FAB).
On December 14, the Alcântara Launch Center (CLA), in the state of Maranhão, hosted the launch of the first hypersonic-aspirated engine vehicle (scramjet the acronym in English) built in Brazil, the 14-X S.
The test was a step in the 14-X Hypersonic Propulsion project, named after Alberto Santos Dumont’s 14-Bis who flew in 1906.
However, while Santos Dumont’s plane had an engine of a mere 50 hp of power that allowed a flight at around 30 km/h, the 14-XS’s scramjet propeller generated around 5,000 hp and reached a speed close to Mach 6 (six times the speed of sound) in the first flight test of the project, started by the FAB in 2008.
The Mach 6 speed achieved by the 14-XS, however, is only a fraction of the potential of scramjet engines.
According to FAB, the system under development in Brazil will be able to fly at Mach 10 (about 12,000 km/h). As a comparison, the Concorde, the last supersonic commercial aircraft, flew at about Mach 2.04 (2,179 km/h).
“In this first flight test, the objective was to establish the starting conditions for the scramjet engine, that is, the validation in a relevant environment of the conditions in which the fuel burning process by the scramjet engine, known as supersonic combustion, is observed ”, informed the FAB in contact with the CNN Brasil Business.
The project foresees at least three more flight tests in the coming years to demonstrate the operation and efficiency of the Brazilian scramjet engine. In the last stage, called 14-XWP, the FAB hopes to have a fully functional autonomous hypersonic vehicle with control and maneuver capabilities.
Relatively simple engine
Unlike jet engines, scramjets have no moving parts such as compressors and turbines that compress the air in the combustion chambers. This type of propellant also does not require ignition systems.
Instead, the burning of the fuel-air mixture occurs by heat in the combustion chamber, which heats up as a result of friction generated by the passage of high-speed air. In a way, the hypersonic engine is relatively simple in design. The hard part is making it work.
The hypersonic engine only “turns on” at very high speeds, as this is the only way it can inhale the massive amount of air necessary to carry out supersonic combustion.
Therefore, it is common for hypersonic vehicles to have two propulsion stages, the first being usually a conventional rocket that accelerates the set to the ideal scramjet trigger point, where separation occurs.
The 14-XS prototype tested at the CLA, for example, was coupled to a Hypersonic Accelerator Vehicle, based on the VSB-30 sounding rocket, built in Brazil by the Aeronautics and Space Institute.
The set flew up to the 30 km altitude range, where the separation took place and then the ignition of the scramjet, which continued accelerating until it ran out of fuel (in this case hydrogen) and reached a speed close to Mach 6, at about 50 km of altitude.
According to the FAB, the demonstrator reached the apogee of 160 km (above the Kármán line, the “frontier” between Earth and space), covering a total of 200 km of distance, and crashed in a safe area in the Atlantic Ocean.
“The scramjet has advantages such as gain in payload space, reduction in the total takeoff weight and the amount of fuel required for the operation of the aircraft for civil or military applications at hypersonic speed”, reported the FAB to the report.
Applications for the scramjet
Scramjet engines are proposed to one day power “space planes,” spacecraft that will be able to take off from Earth, travel into space and return, something NASA’s Space Shuttles did in the past, but at much lower cost. Motorization is also suggested for hypersonic commercial airplanes, predicted for the end of the 21st century.
For now, scramjet technology is beginning to emerge in hypersonic cruise missiles, a type of weaponry that is expected to completely reshape attack and defense doctrines for years to come.
Hypersonic engines have also been tested in drones, which in the future can serve as spy or even combat aircraft.
The most advanced countries in hypersonic research are China, the United States and Russia, with projects for missiles and unmanned aircraft with scramjet engines.
The technology is also being developed for military applications in Australia, France and Japan. Brazil is the newest member of this select group of nations that study hypersonic flight.
Asked what uses the Brazilian hypersonic vehicle can have, the FAB replied that the “project’s objective is essentially to guarantee the domain of technology” of the scramjet engine.
Whatever your application choice, the end result of the 14-X project will be the fastest machine designed and built in Brazil.
Reference: CNN Brasil
I am Sophia william, author of World Stock Market. I have a degree in journalism from the University of Missouri and I have worked as a reporter for several news websites. I have a passion for writing and informing people about the latest news and events happening in the world. I strive to be accurate and unbiased in my reporting, and I hope to provide readers with valuable information that they can use to make informed decisions.
