A model for coupled dynamics of an airframe-propulsion integrated hypersonic airbreathing flight vehicle with various engine safety boundaries, called HIT-HAV (Harbin Institute of Technology), was developed to analyse the couplings among flight dynamics, aerodynamics, propulsion, and control. These engine safety boundaries included inlet unstart boundary, burner wall temperature limitation, burner lean fuel combustion boundary, rich fuel combustion boundary, and so on. All these engine safety boundaries were considered in modelling the HIT-HAV. The validity and practicability of the model were verified by comparing with a full-scale generic hypersonic vehicle. By simulating the HIT-HAV model, the conclusion was drawn that due to the couplings among flight dynamics, aerodynamics, propulsion, and control, the airframepropulsion integrated hypersonic air-breathing flight vehicle may operate, beside the normal operation mode, near some safety boundaries and may even exceed them, which may cause a failure flight. A hypersonic air-breathing flight vehicle's un-safety operation mode could be avoided by limiting the fuel supply, which has been verified in simulations. This paper indicates that for an airframe-propulsion integrated hypersonic air-breathing flight vehicle with various engine safety boundaries, as there were various relevant operation modes requested by various engine safety boundaries, an independent flight control and propulsion control in the traditional sense would fail to satisfy the hypersonic air-breathing flight and hence a multi-mode control design should be the focus of future research.
In this letter, the effect of the dielectric wall temperature on the length and volume of an atmospheric pressure plasma jet (APPJ) is investigated using a single-electrode configuration driven with an AC power supply. To distinguish the APPJ status from the argon flow rate, the three modes, laminar, transition, and turbulent, are separated. When the dielectric wall is heated, the APPJ length and volume are enhanced. Also, the transition regions remarkably expand over a large range of flow rates. The results indicate that different factors contribute to the expansion of the transition region. The increase in the radial and axial velocities is the main cause of the expansion of the transition region to the low-velocity region. The expansion to the high-velocity region is dominantly induced by a change in the viscosity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.