In this paper, a comprehensive approach for design, analysis, and topology optimization for a solid leaf spring landing gear of a quadcopter is presented. Landing gears are a critical structural part of an aircraft that support all up weight in static conditions and absorb kinetic energy in a form of impact loads during touch down. Complete designing along with the analysis of landing gear as per the governing principals and rules have been carried out such that it undertakes static load and impact load of the aerial vehicle having Gross Take-off Weight of 12 kg including the payload capacity of 9 kg. The work includes a comprehensive literature review, mathematical modeling of the strut, calculation of Impact force at static and dynamic conditions. Drop test dynamics has been explained thoroughly which is a prerequisite for experimental verification using drop test of the designed strut before its installation on aerial vehicle. Considering the maximum force encountered during landing, the design of the landing gear along with appropriate thickness has also been undertaken in SOLIDWORKS®. The numerical analysis of the model has been conducted using the continuum approach, considering continuous bodies. Similarly, to validate the proposed design and to determine the structural integrity of strut, finite element analysis has been carried out on landing gear assembly. The deformation, maximum stresses (Von-Mises, Principle Stress) and factor of safety have been computed using SOLIDWORKS®Simulation-Static. Moreover, three materials have been initially used, (Cold Rolled Steel, Al 7075- T6, Al 2024-T3). High strength to weight ration is a critical design consideration for any landing gear strut. The optimization parameter for the analysis is weight of the strut. Hence three optimum variants of the struts have also been proposed with 15%, 35%, 60% reduced weight of each without compromising the strength. The results indicate that the designed strut behaves efficiently meeting all the operational conditions.
Electron-acoustic waves (EAWs) exist in space and laboratory plasmas where two different electron populations, called cool and hot electrons, occur. It has been shown that the distribution functions of both populations of electrons frequently have non-Maxwellian form. In this paper, we investigate that how various plasma parameters change the structure of EAWs by using kinetic theory model. Different forms of kappa distributions are used to model the electron velocity distribution, corresponding to the range of temperatures and kappa values. Dispersion and damping curves illustrate the behavior of EAWs in plasma. The outcomes of these models depict that the cool and hot electron densities are almost equal in regions of weak damping of EAWs. Damping of EA Ws is strong due to hot electrons in low normalized wave number regime. A high normalized wave number regime involves the strong Landau damping due to cool electrons as thermal velocity of cool electrons decreases and become comparable to phase velocity of waves ( $v_{\phi}\sim v_{th_{c}}$ ). It is predicted that the damping of EAWs is strong for high and low values of normalized wave numbers and waves are observable in the range of intermediate value of normalized wave number.
The transmission of power with the help of high voltage alternating current (HVAC) is a conventional technique. On the other hand, transferring huge power over extensive distances using high voltage direct current (HVDC) systems is a developing and advanced technique. Although from 1950, researchers and technologists have achieved significant development in HVDC transmission systems that were base...
This paper presents sloshing analysis of fuel in a supersonic aircraft's fuel tank. Sloshing can be defined as the movement of a fluid inside a moving tank. Sloshing phenomenon is of great significance since it is involved in various fields such as propellant slosh in rockets, aircraft, cargo ships and also the trucks that carry different type of fluids. Sloshing occurs when a fluid containing body suddenly accelerates or decelerates that in turn leads to unnecessary vibrations, flammability, noise and structural failure. To reduce the sloshing effects, anti-slosh baffles are employed in the fuel tanks or any other fluid containing body. Baffles are the obstructions installed inside the fuel tank that absorb the kinetic energy of the waves and reduce the sloshing impact by lowering down the momentum of generated waves. In this research, Volume of Fluid Model has been used for Computational Fluid Dynamics analysis. After the analytical and experimental validation of the model, free surface behavior of sloshed liquid has been analyzed under different operating conditions. For experimental results, a commonly used water tank has been used to track the liquid interface under the application of an external force. Effectiveness of baffles has been studied by calculating the pressure forces on the walls of a fuel tank for both baffled and an un-baffled tank. It has been observed that baffles reduce the pressure forces to almost one tenth in the present case. Reaction forces at the tank mounts have been calculated by carrying out structural analysis of the supersonic fuel tank. Settling time is the time required for the sloshing waves to damp down and the said time for different fill levels and excitation forces has been calculated in the present research. Different cases of acceleration and fuel-fill levels have been taken to study the varying sloshing forces with time. This paper presents a detailed sloshing analysis along with a qualitative and quantitative study that is supported by analytical and experimental results.
It is critical in aircraft design to analyze the behavior, effectiveness, reliability, and other elements of the systems prior to commercial deployment. To design a stable aviation control system, a strong mathematical model of the system is required so that its behavior can be clearly comprehended and regulated. The state-space model of an autopiloted airplane is developed in this article utilizing MATLAB because this simulation model will help gather knowledge in order to make judgments at all phases of airplane development. We focused solely on stability, emphasizing the system's rapid settling without substantial overshoots. The MATLAB state-space model is effectively developed and simulated with and without a controller. The aircraft angle, pitch rate, and pitch angle are chosen as state variables. With the help of the PID controller, we achieved a settling time of 0.0741s and a rise time of 0.0390s.
