The complexity of aeroengine external piping systems necessitates the implementation of automated design processes to reduce the duration of the design ***,existing routing algorithms often fail to meet designer requi...
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The complexity of aeroengine external piping systems necessitates the implementation of automated design processes to reduce the duration of the design ***,existing routing algorithms often fail to meet designer requirements because of the limitations in providing a single solution and the inadequate consideration for route *** this study,we propose the multi-solution pipe-routing method for *** method utilizes a hybrid encoding approach by incorporating fixed-length encoding to represent route constraints and variable-length encoding and indicate free-exploration *** approach enables designers to specify route constraints and iterate over the appropriate number of control points by employing a modified genetic iteration mechanism for variable-length ***,we employ a pipe-shaped clustering niche method to enhance result *** practicability of the newly proposed method is confirmed through comparative experiments and simulations based on the“AeroPiping”system developed on Siemens *** solutions demonstrate significant differences in circumferential and axial orientations while still satisfying engineering constraints.
This work presents an adaptive tracking guidance method for robotic fishes. The scheme enables robots to suppress external interference and eliminate motion jitter. An adaptive integral surge line-of-sight guidance ru...
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This work presents an adaptive tracking guidance method for robotic fishes. The scheme enables robots to suppress external interference and eliminate motion jitter. An adaptive integral surge line-of-sight guidance rule is designed to eliminate dynamics interference and sideslip issues. Limited-time yaw and surge speed observers are reported to fit disturbance variables in the model. The approximation values can compensate for the system's control input and improve the robots' tracking ***, this work develops a terminal sliding mode controller and third-order differential processor to determine the rotational torque and reduce the robots' run jitter. Then, Lyapunov's theory proves the uniform ultimate boundedness of the proposed method. Simulation and physical experiments confirm that the technology improves the tracking error convergence speed and stability of robotic fishes.
Bolt connection is one of the main fixing methods of cylindrical shell structures.A typical bolted connection model is considered as a tuned ***,in the actual working conditions,due to the manufacturing error,installa...
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Bolt connection is one of the main fixing methods of cylindrical shell structures.A typical bolted connection model is considered as a tuned ***,in the actual working conditions,due to the manufacturing error,installation error and uneven materials of bolts,there are always random errors between different *** investigate the influence of non-uniform parameters of bolt joint,including the stiffness and the distribution position,on frequency complexity characteristics of cylindrical shell through a statistical method is the main aim of this *** bolted joints considered here were simplified as a series of springs with random *** vibration equation of the bolted joined cylindrical shell was derived based on Sanders’thin shell *** Monte Carlo simulation and statistical theory were applied to the statistical analysis of mode characteristics of the ***,the frequency and mode shape of the tuned system were investigated and compared with ***,the effect of the random distribution and the random constraint stiffness of the bolts on the frequency and mode shape were *** the statistical analysis on the natural frequencies was evaluated for different mistuned *** some special cases were presented to help understand the effect of random *** research introduces random theory into the modeling of bolted joints and proposes a reference result to interpret the complexity of the modal characteristics of cylindrical shells with non-uniform parameters of bolt joints.
The path planning problem of complex wild environment with multiple elements still poses *** paper designs an algorithm that integrates global and local planning to apply to the wild environmental path *** modeling pr...
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The path planning problem of complex wild environment with multiple elements still poses *** paper designs an algorithm that integrates global and local planning to apply to the wild environmental path *** modeling process of wild environment map is *** optimization strategies are designed to improve the A-Star in overcoming the problems of touching the edge of obstacles,redundant nodes and twisting paths.A new weighted cost function is designed to achieve different planning ***,the improved dynamic window approach(DWA)is designed to avoid local optimality and improve time efficiency compared to traditional *** the necessary path re-planning of wild environment,the improved A-Star is integrated with the improved DWA to solve re-planning problem of unknown and moving obstacles in wild environment with multiple *** improved fusion algorithm effectively solves problems and consumes less time,and the simulation results verify the effectiveness of improved algorithms above.
The article proposes an algorithm for solving the problem of controlling the welding process in robotic technological complexes according to the quality criterion of the products. The statement of the problem is given...
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The models and the algorithms for control the welding process in robotic complexes are considered under conditions of occurrence risk of critical combinations of events leading to emergency situations. Using the appar...
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The primary objective in aircraft transportation is to minimize turbulent drag, thereby conserving energy and reducing emissions. We propose a sector-shaped counter-flow dielectric barrier discharge plasma actuator, w...
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The primary objective in aircraft transportation is to minimize turbulent drag, thereby conserving energy and reducing emissions. We propose a sector-shaped counter-flow dielectric barrier discharge plasma actuator, which leverages jet synthesis for drag reduction. A drag control experiment was conducted in a low-speed wind tunnel with a controlled flow velocity of 9.6 m/s(Re = 1.445 × 10^(4)). This study investigated the effects of varying pulse frequencies and actuation voltages on the turbulent boundary layer. Using a hot-wire measurement system, we analyzed the pulsating and time-averaged velocity distributions within the boundary layer to evaluate the streamwise turbulent drag reduction. The results show that the local TDR decreases as the pulse frequency increases, reaching a maximum reduction of approximately 20.97% at a pulse frequency of 50 Hz. In addition, as the actuation voltage increases, the friction coefficient decreases, increasing the drag reduction rate. The maximum drag reduction of approximately 33.34% is achieved at an actuation voltage of 10 kV.
The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous *** parallel liquid-filled pipe(PLFP)system is also widely used in engineering,and its structure is more complex tha...
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The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous *** parallel liquid-filled pipe(PLFP)system is also widely used in engineering,and its structure is more complex than that of a single ***,there are few reports about the dynamic characteristics of the ***,this paper proposes improved frequency modeling and solution for the PLFPs,involving the logical alignment principle and coupled matrix *** established model incorporates both the fluid-structure interaction(FSI)and the structural coupling of the *** validity of the established model is verified by modal *** effects of some unique parameters on the dynamic characteristics of the PLFPs are *** work provides a feasible method for solving the FSI of multiple pipes in parallel and potential theoretical guidance for the dynamic analysis of the PLFPs in engineering.
The three-electrode sliding dielectric barrier discharge(TES-DBD) plasma actuator significantly enhances the ionization rate and momentum exchange between charged particles and neutral particles by incorporating a par...
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The three-electrode sliding dielectric barrier discharge(TES-DBD) plasma actuator significantly enhances the ionization rate and momentum exchange between charged particles and neutral particles by incorporating a parallel DC electrode into the standard DBD design. This design improves the body force and induced jet velocity while allowing flexible control of the induced jet angle, overcoming the limitations of discharge extension and uncontrollable direction in traditional DBD plasma actuators. An integrated plasma power supply has been designed specifically for TES-DBD plasma actuators, streamlining the power supply management. The methodology involves designing the circuit topology for the TES-DBD power supply, followed by simulating and validating its operating principles using Multisim software. The operational performance of the power supply is evaluated through a comprehensive analysis of its electrical,thermal, and aerodynamic properties specific to TES-DBD plasma actuation.
Dielectric barrier discharge(DBD)plasma actuators are widely used in active flow control due to their simple design and rapid ***,they need more effectiveness and discharge *** overcome these limitations,a sector-shap...
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Dielectric barrier discharge(DBD)plasma actuators are widely used in active flow control due to their simple design and rapid ***,they need more effectiveness and discharge *** overcome these limitations,a sector-shaped dielectric barrier discharge(SS-DBD)plasma actuator with an adjustable jet angle was developed to enhance flow control *** flow field dynamics induced by the SS-DBD plasma actuator were quantitatively analyzed using particle image velocimetry(PIV).Experimental investigations showed that precise adjustments to the actuation voltage can modulate the maximum velocity of the induced ***,a quasi-linear relationship between the sector-shaped angles of the SS-DBD and the deflected jet angles was established,indicating that changes in the sector-shaped angles directly influence the direction of the deflected *** correlation enables precise control over jet angles,significantly enhancing flow control by adjusting the SS-DBD-PA's sector-shaped angle.
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