Primary investigation highlights potential of Ram-Rotor Detonation Engine

Primary investigation highlights potential of Ram-Rotor Detonation Engine
by Clarence Oxford
Los Angeles CA (SPX) Dec 04, 2024

Detonation, a supersonic combustion wave driven by shock waves and chemical energy, is a powerful means of converting chemical energy into thrust. This method has long been explored to enhance aerospace propulsion by improving thermodynamic cycle efficiency. Since the 1950s, various detonation engines, such as pulse detonation engines, oblique detonation engines, and rotating detonation engines, have been proposed. However, these designs face challenges like limited thrust continuity, high starting Mach numbers, and insufficient performance benefits, restricting their broader adoption.

In a recent study published in the *Chinese Journal of Aeronautics*, researchers from Tsinghua University, Dr. Haocheng Wen and Prof. Bing Wang, introduced a novel propulsion concept called the Ram-Rotor Detonation Engine (RRDE). This innovative design addresses the limitations of previous detonation engines.

"The original intention of developing this new engine is to improve the structures of rotating detonation engines," explained Dr. Haocheng Wen. "This concept is also inspired by the ram-rotor compressor." The RRDE features a rotating rotor with helical symmetric blades within a stationary casing. Within these variable cross-sectional channels, the combustible mixture undergoes compression, detonation, and expansion, driving propulsion.

The researchers conducted theoretical and numerical investigations to evaluate the RRDE. Using a theoretical model, they analyzed how parameters such as inlet velocity, rotor rim velocity, and equivalence ratio influence propulsion performance. For a stoichiometric hydrogen/air mixture, their analysis showed that the total pressure gain of the RRDE could exceed 3. Numerical simulations also revealed that detonation waves remain stable and stationary within the blade configuration and adapt to variations in the equivalence ratio within certain limits. "Our study primarily verifies the performance benefits and operation feasibility of the RRDE," said Dr. Wen.

The RRDE offers several potential advantages, including a compact structure, high efficiency, and adaptability to a wide range of flight Mach numbers. However, challenges such as stabilizing detonation waves, managing supersonic boundary layer interference, developing high-speed rotors, and ensuring thermal protection must be addressed. "Our team is conducting ongoing research on key scientific and engineering issues in RRDE," added Prof. Bing Wang. The team anticipates that the RRDE could power supersonic vehicles in the future.

Research Report:Primary investigation on Ram-Rotor Detonation Engine