Chinese scientists have tested a prototype supersonic rocket engine that is twice as efficient as similar engines. For this, a new solid fuel feed technology has been used, allowing more efficient combustion, informed the South China Morning Post, citing a study published in the scientific journal Solid Rocket Technology.
A hypersonic ramjet (scramjet) is a type of jet engine in which the combustion of fuel and oxidizer – i.e. air taken from the atmosphere – occurs in a special chamber at supersonic speeds.
The problem with these engines is that the faster the air enters the combustion chamber, the less fuel is burned, i.e. fuel efficiency is reduced.
Scientists led by Ma Likun from the University of Defense Science and Technology of the People’s Liberation Army of China tested a promising prototype engine in which, thanks to the new air supply system, a considerable increase in energy efficiency has been achieved. The prototype uses powdered boron as fuel, a substance with a high calorific value.
The experiment was carried out in a wind tunnel, in which the speed of the oncoming air flow was Mach 6, the flight was simulated at an altitude of 25 km.
At the start of the experiment, engineers squirted boron powder into the air intake and monitored fuel combustion in the combustion chamber. Then the scientists launched the fuel into the combustion chamber not through one nozzle, as is standard procedure, but through several. Due to this, a shock wave was formed in the combustion chamber, which moved towards the supersonic airflow and slowed it down below the speed of sound, which ensured more combustion. full of fuel.
Evidence of more complete fuel combustion was the temperature in the combustion chamber, which reached 3,000 degrees Celsius, about double the usual temperature inside.
During the experiment, an energy efficiency of 79% was achieved, which is twice the performance of existing similar engines that can be used mainly in hypersonic missiles. With increased fuel efficiency, these rockets can fly longer, which means farther.
“The solid propellant scramjet has a number of advantages, such as a simple design, high specific impulse, combustion stability and the ability to operate in a wide range of speeds,” the author pointed out. ‘work.
