SABRE Precooler by Reaction Engines: Testing at Mach 5 Conditions

Just imagine a super hypersonic passenger airplane that could hit the distance during the journey from London to, let it be, New York for one and a half hours. Sounds unbelievable? Don’t laugh because this is real due to Mach 5, or. In other words, five times the speed of sound. According to that feature, a plane would be able to cope with a trip across the Atlantic in about one hundred and twenty-two minutes.

Mach 5 is considered around fifty percent quicker than the SR-71 Blackbird which is acknowledged as the fastest jet-engine powered plane in the world. Additionally, it is two times faster than the cruising speed of Concorde. What the most exciting is, it would take a maximum of three hours to conduct a flight across the Pacific. Moreover, flight time would be reduced up to eighty percent (!), if they travel from London to Sydney. This leads to extremely economical propellant use.

It sounds like the most eager wish of air trip lovers. In the future, Mach 5 aircraft may even become a serious opponent to such eco aerospace achievements as solar-powered drones .

Anyway, to gain such an ambitious speed, engineers worldwide should design a completely innovational airplane engine that modern science has never previously faced. However, it seems the most talented engineering specialists from the UK have got things moving!

Revealing the 30-years Project

Recently this year, Reaction Engines Limited, a British aerospace manufacturer , decided to show the world a possible new future within the solution that has been growing through for thirty (!) years.

Reaction Engines Limited started its engineering activity in 1989 due to challenging plans of three propulsion engineers from Rolls Royce. Thirty years ago, they got ill with an idea to construct an aircraft that could reach supersonic speeds or Mach 5. They shared the opinion that for an engine to succeed in supersonic speeds, the air coming into the engine should have to be speedily cooled. Otherwise, the possibility raises hat the engine would simply melt. This was a challenge for the whole aerospace segment, not only for such aerospace experts as Alan Bond, John Scott-Scott, and Richard Varvill.

Managing the “Precooling” Challenge

Finally, the engineering team has invented the heat exchanger or “precooler” as an integral part of their air-breathing rocket engine. It is capable of chilling the air to minus one hundred and fifty degrees centigrade maximum in less than a twentieth of a second.

These extra-light heat exchangers will assist an aircraft in flying over Mach 5 in the atmosphere. So, in this way, the SABRE (Synergetic Air-Breathing Rocket Engine) was born. According to Chris Skidmore, the fourth UK science minister, the SABRE engine with a pre-cooling system rightly belongs to the most breathtaking engineering solutions in the UK. For sure, this technology will modify the ways we travel worldwide and how they launch satellites into orbit.

How it Functions

The precooler heat exchanger possesses thousands of light-gauge tubes. The coolant is passed through those tubes. It guarantees a high surface-to-weight proportion that allows chilling extremely high airflow temperatures in a matter of a second. As a result, the engine gets the cool ambient air, which it requires to work efficiently.

The SABRE Engine with precooler consumes air, thus contributing to twenty percent of the journey to orbit. As far as those twenty percent are implemented, the engine comes to rocket mode to successfully complete a trip.

The precooler is constructed to absorb more than five megawatts of hot energy from the incoming hot air passing through it. Therefore, the outlet air temperature is a few degrees above ambient.

Details Regarding Testing SABRE Precooler

Here, it should be mentioned that the representatives of Reaction Engines Limited shared only a few details concerning the testing procedure.

All we know is that the full test assembly, as well as all the equipment needed to perform the demonstration, was developed, constructed, and assembled by Reaction Engines and its partners at the company’s headquarters in Oxfordshire in the UK.

In October 2019, an innovative precooler was tested at airflow temperature conditions in accordance with Mach 5. The testing demonstrated how the precooler may overcome the extreme temperatures.

Note that the ground-based testing undertaken in April 2019 has successfully coped with the challenge facing the highest temperature indicator of the HTX testing program developed by Reaction Engines Limited. The testing took place on the location (specially designed facility) in the AS called Colorado Air and Space Port.

The audience witnessed the SABRE precooler efficiently function at temperatures as of around four hundred and twenty degrees in Celsius which is approximately seven hundred and eighty-eight degrees in Fahrenheit. This result ideally fits the thermal conditions for the flight as of Mach 3.3 characteristics.

During one of the latest hot testing programs conducted by the manufacturer in November, the SABRE precooler managed to cool airflow temperatures as of one thousand degrees in Celsius during less than one of the twentieth of a second. The results are off the charts!

The test revealed the ability of the device to proficiently chill airflow at speeds above the operational limits of any type of jet-engine powered aircraft. The manufacturer’s engineering team has managed to accomplish the thing considered impossible to realize in the past.

The chief executive of Reaction Engines Limited, Mark Thomas explains that besides the use of their precooler as a component of the air-breathing rocket engine, the device has the potential for commercial applications in many spheres. The precooler delivers high-quality heat transfer capabilities at both compact size and light weight. Thus, even at the stage of testing, the company sees the interest of technology partners and potential clients.

Industries to Imply

The creators consider the precooling technology to be applied not only to hypersonic flight. The manufacturer assures that it would contribute much to improving the performance of already existing jet engine solutions. For instance, it is an ideal component for engineering systems in such spheres as aerospace, automotive, various industrial procedures, and energy sector.

Funding for the Solution

A few years ago, Reaction Engines received a solid development funding (naturally, the sums are kept in secrecy) from three reputable institutions including:

· The European Space Agency;

· The British government;

· The US Defense Advanced Research Projects Agency or DARPA (more details about their investment in the project may be found on DARPA’s official website ).

Moreover, the company got more than a hundred million pounds from private investors and public organizations. SABRE precooler attracted such giants as Rolls-Royce, BAE Systems, and the investment team of Boeing HorizonX Ventures that finances startups with revolutionary concepts.

So, having more than decent financial support, Reaction Engines are about to start designing and testing the available-for-sale version of the SABRE engine with precooler in 2020.

Following the significant testing challenge, the company is also working on the next steps of the SABRE project which is going to be officially presented in 2022. Unfortunately, no more details for now.