Mach 5 supersonic aircraft engine

Theo BGR, A team of engineers at the Japan Aerospace Exploration Agency (JAXA), Waseda University, the University of Tokyo and Keio University have completed a ground-based combustion test with a ramjet engine on a 6,174 km/h (Mach 5) supersonic aircraft. This is part of a research project focusing on chassis and propulsion control for hypersonic vehicles.

The team installed the test aircraft inside the ramjet engine test facility at JAXA’s Kakuda Space Center in Miyagi Prefecture. The test aircraft was attached to a wind tunnel that simulated conditions at an altitude of about 25 km, where the air is 100 times thinner than at sea level. At that altitude at a speed of Mach 5, the air around the nose and leading edge of the aircraft can reach temperatures of over 1,000 degrees Celsius, posing a major challenge to supersonic design.

To handle such high temperatures, engineers built an advanced heat protection system that helps maintain internal temperatures near normal operating levels. At the same time, the sensor network maps surface heat distribution to check calculations of the impact of temperature on structures, providing important information for the production of full-size passenger vehicles. The researchers also measured the temperature distribution of exhaust gases from hydrogen-fueled ramjet engines to collect data on environmental impacts.

Theo Interesting Engineeringtesting confirmed the aircraft’s anti-heat system, control surfaces and ramjet engine achieved high performance in supersonic conditions. At Mach 5, the heat-resistant structure successfully maintained the aircraft’s internal temperature at near-normal levels, allowing electronics and controls to operate correctly throughout the test.

Unlike conventional aircraft, hypersonic vehicles require close integration of airframe and engine design because airflow and thrust directly affect each other at extremely high speeds. Shock waves formed around the aircraft alter the airflow into the engine while thrust affects the aerodynamic stability of the aircraft.

The Ramjet, the core technology of the test, is an aspirated jet engine with no moving parts. This type of engine relies on rapid forward motion to compress air before mixing it with fuel and burning it to create thrust, helping to reach speeds far beyond the capabilities of conventional turbine engines. However, the ramjet engine cannot operate in a stationary state and needs to accelerate to supersonic speed first.

The test’s success shows that Japan is far ahead in solving the major aerospace engineering challenge of maintaining engine stability, structural integrity and heat resistance when traveling at supersonic speeds. The next phase of the program includes mounting a test aircraft on a rocket for actual flight at Mach 5. According to JAXA, future applications include building an aircraft capable of traveling between Japan and the United States in about two hours, significantly reducing trans-Pacific flight times from the current average of 12-14 hours.

Theo NASAMach speed, named after physicist Ernst Mach, is a unit of measurement between the speed of an object and the speed of sound in the same environment, commonly used in military aviation and space. Mach 1 is equal to the exact speed of sound (1,235 km/h) at sea level. If flying at Mach 5, the plane is flying five times faster than the speed of sound in the air. Many military aircraft reach Mach 1.6-3. In aviation history, two passenger models that reached supersonic speeds were the British-French Concorde (Mach 2.04, about 2,410 km/h) and the Soviet Union’s Tupolev Tu-144 (Mach 2.35, about 2,500 km/h).