Stabilized detonation for hypersonic propulsion

Abstract

Future terrestrial and interplanetary travel will require high-speed flight and reentry in planetary atmospheres by way of robust, controllable means. This, in large part, hinges on having reliable propulsion systems for hypersonic and supersonic flight. Given the availability of fuels as propellants, we likely will rely on some form of chemical or nuclear propulsion, which means using various forms of exothermic reactions and therefore combustion waves. Such waves may be deflagrations, which are subsonic reaction waves, or detonations, which are ultrahigh-speed supersonic reaction waves. Detonations are an extremely efficient, highly energetic mode of reaction generally associated with intense blast explosions and supernovas. Detonation-based propulsion systems are now of considerable interest because of their potential use for greater propulsion power compared to deflagration-based systems. An understanding of the ignition, propagation, and stability of detonation waves is critical to harnessing their propulsive potential and depends on our ability to study them in a laboratory setting. Here we present a unique experimental configuration, a hypersonic high-enthalpy reaction facility that produces a detonation that is fixed in space, which is crucial for controlling and harnessing the reaction power. A standing oblique detonation wave, stabilized on a ramp, is created in a hypersonic flow of hydrogen and air. Flow diagnostics, such as high-speed shadowgraph and chemiluminescence imaging, show detonation initiation and stabilization and are corroborated through comparison to simulations. This breakthrough in experimental analysis allows for a possible pathway to develop and integrate ultra-high-speed detonation technology enabling hypersonic propulsion and advanced power systems.

Research on Optical Diagnostic Method of PDE Working Status Based on Visible and Near-Infrared Radiation Characteristics

“…Based on the unique characteristics of radiation signals, a determination method of PDE fill fraction is proposed, i.e., the time spent in the detonation products exhausting process can be obtained according to the characteristics of radiation signals in each process, and then the filling condition of fuel in detonation tube can be calculated. (2) In this experimental study, the detonation and deflagration are found through pressure measurement. The radiation signals of detonation and deflagration are significantly different, and the radiation signal generated by detonation wave is much larger than that of the deflagration wave.…”

“…Compared with the traditional pressure sensor test method, the spectral radiation method has obvious advantages in identifying the combustion mode: (1) By analyzing the visible radiation signal in the detonation process, the online monitoring of the performance of the detonation engine can be realized by obtaining the working state as well as the fill fraction of the detonation engine at the same time, while the traditional method can only realize the simultaneous measurements by using many more sensors. (2) The spectral radiation test is non-contact, which can avoid the problems of inconvenient installation of conventional contact test methods and sensibility to the environment temperature.…”

“…A detonation wave is a kind of supersonic combustion wave that consists of shock waves driven by energy release from closely coupled chemical reactions, which has broad application prospects in the field of aerospace propulsion technology [1][2][3][4][5]. As one of the innovative propulsion devices, a pulse detonation engine (PDE) generates thrust by using detonation waves and has attracted great attention due to its simple structure and high thermodynamic cycle efficiency [6][7][8].…”

A three-dimensional discrete Boltzmann model for steady and unsteady detonation

“…It consists of a precursor shock travelling at supersonic speed and a reaction zone immediately behind the shock. Applications can be found in areas such as detonation engines [2,3] and plasma-detonation deposition [4]. On the other hand, uncontrolled detonation may damage equipment and cause injury [5].…”

Oblique Detonation Wave Control with O3 and H2O2 Sensitization in Hypersonic Flow

“…The oblique shock compresses the fuel-air mixture, and at appropriate compression (combination of θ with θ CJ < θ < θ detach and M ∞ ), the oblique shock will transit into an oblique detonation wave through two mechanisms: abrupt transition and smooth transition [7]. The abrupt transition consists of oblique shock with a non-reactive initiation zone, deflagration wave and an oblique detonation wave forming a triple point [4,8,9]. In contrast, a smooth transition occurs with a curved shock at high Mach numbers with a requirement of a low activation energy condition.…”