فهرست مطالب mohammadhossein moghimi-esfandabadi

This research delves into the intricate realm of supersonic inlet design for ramjet engines, honing in on the critical aerodynamic considerations and optimization of performance factors. At Mach 2.5, the study meticulously scrutinizes pivotal design parameters, including the placement and number of inclined shocks, cowl-lip positioning, throat area, spike location, and diffuser length. Computational fluid dynamics simulations are harnessed to unravel the intricate flow dynamics and assess the proposed inlet geometry's performance.The findings reveal a nuanced relationship between back pressure and shock wave positioning, where increasing back pressure initiates a shift in the shock wave, impacting the flow state. The paper delineates this transition, emphasizing the pivotal back pressure range of 300,000 to 350,000 pascals, where optimal shock wave alignment corresponds with design parameters, achieving a supercritical state.However, elevating back pressure beyond this range triggers a sub-critical state and mass flow overflow as the shock exits the throat.the study explores various performance metrics, encompassing drag coefficient, distortion coefficient, mass flow ratio and total pressure recovery under varying back pressure conditions. The outcomes underscore the merits of higher back pressures, which mitigate drag coefficient and distortion while amplifying TPR.In the sub-critical state, MFR diminishes due to shock wave displacement beyond the intake opening.This research illuminates the intricate dance of aerodynamics within ramjet engine inlets and underscores the paramount significance of optimizing inlet geometry to unlock heightened performance. It effectively encapsulates the essence of the full article, enticing readers to embark on a deeper exploration of this crucial area of aerospace engineering.

This research investigates the effect of fence on wingtip vortices and control surfaces in a bird-like aircraft using numerical methods. In designing and placing the fence, average dimensions extracted from wing root vortices at different angles of attack have been used. In addition, the fence with specified dimensions have been installed at three heights and three different positions along the wing (the length of the winglet is equal to the average length of the vortex in that part, and the height of the winglet is 30% of the diameter of the vortex in that part) and have been examined at angles of attack ranging from 7 to 16 degrees. The next stage of the study is the optimal design of the dimensions of the control surfaces using a single objective optimization method. The aim of this research is to achieve the best possible design that converges to an optimal solution with minimum time and cost. The design of control surfaces is carried out at three points based on the dimensions of the wing root vortex using numerical methods. However, Computational Fluid Dynamics (CFD) analysis requires a lot of computational time.

This paper explores strategies to enhance safety, reliability, and performance in military-dependent industries, focusing on five key dimensions. Diversity is highlighted as crucial for effective defence, enhancing system resilience and safety by integrating various capabilities. Technological innovation in AI and robotics empowers military domains against threats, reducing performance risks. The impact of advanced technologies on effectiveness is analyzed. Military infrastructure is emphasized for mission success, with strong, flexible infrastructure vital for safety and reliability. The review examines the role of robust infrastructure in risk reduction. Human resources are crucial, with targeted training programs empowering specialized forces. The importance of investing in human resources is underscored. Communication and coordination among military systems are essential for success, with effective collaboration being complex but necessary. The review provides a roadmap for optimizing system performance in the military field, addressing the dynamic and evolving nature of military applications. This comprehensive approach ensures that military systems are robust, reliable, and capable of meeting contemporary challenges.

Numerous studies have demonstrated that human factors are the primary cause of deadly air incidents and accidents involving passenger flights. Human error is defined as mistakes and flaws in the way a human component of a system performs a predetermined action or refrains from performing an activity that is forbidden or that needs to be completed within a given amount of time, with a specific degree of precision, or both. Vision error, measurement units, radio communication, language, aircraft warning system design, psychological stress, pilot selection and qualification, pilot flight qualification, fatigue, aging, human performance, flight crew coordination, modifications to the Course of Cadin course, and human factors in aircraft design are the typical categories into which such errors are divided. Based on international norms and indications, the investigation's findings demonstrate that the Civil Aviation Organization's supervision in the sensitive area of ISI has been appropriately followed. This matter is significant because, since 2010, the Civil Aviation Organization has complied with its standards optimally based on international audits. This is because, among domestic experts, compliance with international standards has always been a top concern in increasing safety and productivity in this field. However, determining if this issue is sufficient to establish safety and prevent accidents is crucial. In this research, we examine the risk method for flight safety, the performance evaluation index of safety, security, and flight safety by passengers, and the most important golden tips to save from plane crashes.

Risk management and technical integrity of air systems are critical in the aviation industry. Maintenance grouping, as one of the main risk management tools in the aviation industry, refers to activities aimed at maintaining and improving the technical integrity or reducing the risk of maintaining aviation systems. Since there may be a set of equipment and parts in an air system that need maintenance or repair, optimization of maintenance grouping can improve performance and increase the safety and technical accuracy of the air system. This article will analyze and review the optimization methods of maintenance grouping in air systems. First, the importance of risk management and the technical accuracy of air systems will be examined, and then a detailed description of the maintenance grouping steps will be discussed. In the following, various optimization methods and algorithms used to improve maintenance grouping performance will be reviewed. Then, the advantages and limitations of each method will be discussed. In the end, the results of this research and its critical implications will be evaluated, and suggestions will be made to optimize maintenance grouping in air systems. The study results show that the genetic algorithm can improve resource utilization, scheduling efficiency, and cost reduction in maintenance grouping. This can significantly benefit the aviation industry, as it can help reduce costs, improve aircraft availability, and enhance safety.

In this research, the placement of the split drag control system along the length of the UAV wing and its effect on the aerodynamic coefficients are numerically investigated. This control system consists of two plates on top of each other, which, when opened, creates a pressure drag in one wing. This system is used to create a yawing moment in flying wing airplanes. Flying wing airplanes have a high sensitivity for determining the location of control surfaces due to the presence of the swept back angle in the wings and the formation of the wing apex vortex at high angles of attack in this type of configuration. Here, for the installation and positioning of the split drag control system, from a static point of view, it is necessary to install the moving surfaces of the split drag at the end of the wing, because the maximum moment arm will be in this part, which causes the production of the maximum yawing moment; However, from the aerodynamic point of view, the placement of the control surface in this range always has disadvantages due to the existence of the wing tip vortex and the wing apex vortices. Therefore, here it has been trying to place the split drag system in 3 different opening angles in 3 longitudinal positions relative to the tip of the wing and check the resulting moments in different angles of attack. The aim of this research is to increase the yawing moment and decrease the rolling moment coefficients.