Based on numerical modeling of the flow aerodynamics of a cascade-type thrust reverser located in the outer contour of a turbofan engine, at the switch-on stage during the flap repositioning, the dynamic characteristics of the flow impact on the flap and blades of the thrust reverser were determined. The numerical model was verified based on the results of the experimental study.
The paper examines the problem of controlling a gas turbine engine as a multidimensional object with a single control action and a control channel selector. It is shown that an effective means of constructing such logical-dynamic systems is adapting the dynamic characteristics of channel switching modes to changes in the system structure. A method for increasing the system noise immunity to step and random disturbances is considered. A fuel consumption control loop for a gas turbine engine is synthesized. Simulation results are presented. The good quality of the developed adaptive noise-immune system is noted.
Heat transfer coefficient was estimated theoretically based on Lyon’s integral near the point of the onset of thermal boundary layer in a channel. The profile of flow temperature was assumed uniform or close to uniform. The profile of velocities at the channel inlet was also considered uniform. Additionally, the study focused on the behavior of heat transfer in developed flows in channels. Estimated results were compared with heat transfer coefficient in developed (in terms of dynamic and thermal boundary layers) flows in channels.
The paper compares the loop gain frequency characteristics of a buck converter with two-loop feedback for the output voltage and inductor current against the loop gain frequency characteristics of a buck converter with two-loop feedback for the output voltage and transistor current. The reasons for the discrepancy in the loop gains frequency characteristics of the converters are shown. It is shown that the PWM modulator in the transistor current feedback converter has parametric gain. A linear model of a converter with two-loop feedback for the output voltage and transistor current is presented, the loop gains frequency characteristics of which confirmed the correctness of the model proposed.
A vibration resistance criterion was developed for solving the problem of automated placement of components on a printed circuit board for aircraft electronics. Mathematical modeling of vibration resistance was conducted for a specific placement of decoupling capacitors on the printed circuit board. A comparative analysis of the results of automated placement of decoupling capacitors on the printed circuit board with and without the vibration resistance criterion was conducted.
