On Distributed Electric Propulsion (DEP) aircraft, the deployment of numerous high-lift propellers with small diameters on the wing’s leading edge significantly enhances lift during low-speed flight. The increase in the number of propellers leads to a decrease in diameter, which increases the disc loading. In this paper, a rapid design method applicable to heavy-loaded propellers is developed and does not require iterative calculations compared to traditional heavy-loaded propeller design methods, enabling rapid completion of the propeller design. The results of CFD computation show that the relative thrust error of the method proposed in this paper is within 5% for disc loading ranging from 600 Pa to 1400 Pa, features a high-accuracy design of propellers with required thrust, and high thrust coefficients are achieved within large advance ratio range.

According to the coupling characteristic of propulsion system and impact system of hydraulic rock drill, deduced the calculation formula of optimal axial thrust for the propulsion system of hydraulic rock drill. On the basics of the calculation formula before, the paper constructed compound driven propulsion system of hydraulic rock drill based on electro-hydraulic proportional pressure-reducing valve and high speed on-off valve, and established its dynamics model. Finally, the paper considered optimal axial thrust as the goal, and adopted the fuzzy PID control strategy to realize on-line, intelligent control to axial thrust of the propulsion system of hydraulic rock drill. Through mathematical modelling and simulation study show that fuzzy PID control method has its advantages as the fast response follow by target, high control precision, and small fluctuation, and provided theory reference and technology method for intelligent control of the propulsion system of hydraulic rock drill.

During high-speed flight in the atmosphere, aircraft with optical windows endure severe aerodynamic heating challenges. This study focuses on a supersonic optical dome with planar side windows. Numerical simulation methods are employed to investigate the effects of the supersonic film pressure, the film Mach number, and the type of cooling gas on the cooling performance of the film. The results indicate that the introduction of a film can alter the velocity profiles of the flow field. Increase in the the static pressure ratio and the exit Mach number of the film can extend the effective cooling length and enhance the cooling effectiveness. This improvement primarily arises from the increased film thickness above the optical window, which better isolates the window from the mainstream. Additionally, this increase suppresses the growth rate of the mixing layer generated by the interaction between the film and the mainstream, thereby extending the length of the potential-core region. However, the excessively high static pressure ratio and the Mach number can lead to waste of the cooling gas. Under the same static pressure ratio and Mach number, NH₃ exhibits a higher mass flow utilization rate and can be considered in future film cooling designs.