When axial compressors operate under high-loading conditions, inherent unsteady flow phenomena emerge in the tip region as a consequence of the tip leakage flow. These aerodynamic phenomena are collectively known as tip flow unsteadiness. It has been proven that tip flow unsteadiness not only serves as an excitation source of both non-synchronous vibration and tip noise but is also the cause of short-length-scale

Aviation’s emissions are among the hardest to eliminate. There are a handful of solutions: battery-electric propulsion, hydrogen fuel cells, hydrogen combustion, and synthetic hydrocarbon fuel produced with carbon from the air. All of these solutions rely on renewable electricity, a resource that will be in short supply as other industries use it to decarbonize. Depending on the flight distance and

This paper presents a review of recent literature on the application of retro-propulsion in earth based rocket systems, with a specific focus on the recent advancements and challenges associated with the prediction of aerothermal and aerodynamic characteristics of re-usable boosters. It gives an overview of current system architectures and mission profiles, while discussing the trends in future vehicle

Due to the growing threat from space debris and the accelerating increase in the number of active satellites, Active Debris Removal (ADR) and In-Orbit Servicing (IOS) missions are currently being developed. A robotic manipulator mounted on a servicing satellite will enable precise grasping of a target object and is needed to perform complex servicing tasks. This paper presents a comprehensive review

Sustainable aviation is a frequently discussed concept in contemporary aviation literature, industry, and policy. However, a review of definitions for sustainable aviation indicates that there is limited agreement as to what sustainable aviation entails. Most definitions include an increase in aircraft efficiency or introduce alternate energy systems in an attempt to decrease overall emissions, but

Space sails are a continuum of lightweight, thin, large-area, deployable technologies which are pushing forward new frontiers in space mobility and exploration. They encompass solar sails, laser-driven sails, drag sails, magnetic sails, electric sails, deployable membrane reflectors, deployable membrane antennas, and solar power sails. Some have been flight tested with operational heritage, while some

As humankind prepares to establish outposts and infrastructure on the Moon, the ability to manufacture parts and buildings on-site is crucial. While transporting raw materials from Earth can be costly and time-consuming, in-situ resource utilization (ISRU) presents an attractive alternative. This review paper aims to provide a thorough examination of the current state and future potential of Lunar-based

Vortex loops are compact toroidal structures wherein fluid rotation forms a closed loop around a fictitious axis, manifest in many natural occurrences. These phenomena result from brief impulses through vents or apertures in fluid systems, such as in caves, volcanic crusts, downbursts, or the descent of liquid droplets. The majority of naturally occurring and laboratory-generated vortex loops, studied

Due to the significant improvement in computing power and the rapid advancement of data processing technologies, artificial intelligence (AI) has introduced new tools and methodologies to address the challenges posed by high nonlinearity and strong coupling characteristics in traditional supersonic flow and combustion. This article reviews the considerable progress AI has made in applications within

This paper reviews the development and state-of-the-art research of attitude control technologies for launch vehicles, as well as the application evaluations of the responsive tolerant control (RTC) technology. First, the control theories and methods related to launch vehicles are classified and surveyed. Although studies in this field are still active, many new methods have not exhibited impressive

Lattice structures, produced by repeated unit cells in the particular pattern, offer a high strength-to-weight ratio. The current advancement in Additive manufacturing (AM) technology, creating complex geometries like lattice structures has revolutionized production across various industries. While several reviews have focused on different specific aspects of lattice structures, a comprehensive overview

Concentrated vortex flows contribute to the aerodynamic performance of aircraft at elevated load conditions. For military interests, the vortex flows are exploited at maneuver conditions of combat aircraft and missiles. For transport interests, the vortex flows are exploited at takeoff and landing conditions as well as at select transonic conditions. Aircraft applications of these vortex flows are

The Cislunar region is crucial for expanding human presence in space in the forthcoming decades. This paper presents a comprehensive review of recent and anticipated Earth–Moon missions, and ongoing space domain awareness initiatives. An introduction to the dynamics as well as periodic trajectories in the Cislunar realm is presented. Then, a review of modern Cislunar programs as well as smaller missions

Compared with traditional deflagration-based systems, detonation-based propulsion systems offer significant potential benefits in terms of efficiency and specific impulses in the field of advanced aerospace propulsion technologies. However, the successful implementation of these technologies faces several key challenges, particularly in achieving reliable, stable, and robust detonation wave propagation

This paper presents a comprehensive review of recent advancements in modelling approaches, design strategies, and testing techniques applied to friction damping in turbomachinery. It critically evaluates experimental testing, design processes, and optimisation studies, along with the latest developments in numerical modelling techniques. The review begins with an overview of vibration mitigation methods

To ensure the secure operation of space assets, it is crucial to employ ground and/or space-based surveillance sensors to observe a diverse array of anthropogenic space objects (ASOs). This enables the monitoring of abnormal behavior and facilitates the timely identification of potential risks, thereby enabling the provision of continuous and effective Space Situational Awareness (SSA) services. One

The academic community has extensively studied fault management in dynamical and cyber-physical systems, leading to the development of various model-based and data-driven/learning-enabled methods. Although these advanced designs show promise for improving conventional practices in aircraft systems, there is a noticeable disparity between academic methodologies and the specific needs of the aviation

Reducing the sonic boom to a community-acceptable level is a fundamental challenge in the configuration design of the next-generation supersonic transport aircraft. This paper conducts a survey of recent progress in developing efficient low-boom design and optimization methods, and provides a perspective on the state-of-the-art and future directions. First, the low- and high-fidelity sonic boom prediction

Crashworthiness is the ability of civil aircraft fuselage structure and internal systems to maximum protect the occupants’ safety in a crash or emergency landing event, and is an important embodiment of the civil aircraft safety, which can determine the occupant survivability to a certain extent. The crashworthiness is dominated by the crash response characteristics of typical fuselage section (including

In recent years, high-order discontinuous Galerkin (DG) methods have emerged as an attractive approach for numerical simulations of compressible flows. This paper presents an overview of the recent development of DG methods for compressible flows with particular focus on hypersonic flows. First, we survey state-of-the-art DG methods for computational fluid dynamics. Next, we discuss both matrix-based

the passive safety of aircraft passengers is such an important aspect in the design of aircraft structures as strength and fatigue concerns. The development of methods and devices to prevent passenger injuries is the subject of continuous efforts. The mission is to minimize stresses and accelerations on passengers during a crash. Over the years, studies on crash phenomena have been focused on experimental

Aero-optical effects have received increasing attention in recent decades with the continuous development of high-speed missiles’ imaging guidance systems, airborne laser systems, and laser communication systems. Numerous experiments and engineering practices have shown that the aero-optical effects of the supersonic turbulent shear layer can reveal the essential characteristics of general aero-optical

This review article offers an in-depth analysis of cooperative motion planning and control in aerial-ground autonomous systems, emphasizing their methods and applications. It explores the integration of unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs), focusing on their synchronized planning and control mechanisms that enable efficient task execution in various settings, such as

The history of satellite development is at an inflection point: around half of all countries have made and launched satellites, while another half has not. In this context, the time appears right to take stock of lessons learnt from the development of country-first domestic satellites. These are defined as the first to have been designed, assembled, integrated, and/or tested with significant input

The crashworthiness of a structure is a measure of its protective capability under dynamic events by absorbing the crash energy in a controlled way. Fiber reinforced composite materials can represent a valid alternative to ductile metals as impact energy absorbers in a crashworthy structure. In fact, composites are characterized by high mechanical properties coupled with low weight, capability to be

Airplanes are inevitably subjected to various impact loading conditions in the event of emergency landing. An airplane crash scenario is a complex nonlinear impact event which involves large deformation, material fracture, structural failure, and dynamic contact. The impact response becomes more complicated due to the presence of composite materials, which are becoming the dominated choice for aircraft

One of the most critical air transportation issues is the passengers' protection during collision and impact events that must be absorbed in a controlled way in order to reduce damages. The capability of an aircraft to eliminate injuries in relatively mild impacts and to reduce severe effects on occupants in critical crashes is called crashworthiness. The crashworthiness is the ability of a structure

This paper reviews several decades’ worth of research on the topic of slat noise arising from high-lift systems of commercial aircraft. A high-lift system is commonly used for providing additional lift by deploying the leading-edge slat(s) and trailing-edge flap(s) during the takeoff and landing phases of flight. Slat noise can be one of the main sources of airframe noise, along with the deployed landing

Performances are a key concern in aerospace vehicles, requiring safer structures with as little consumption as possible. Composite materials replaced aluminum alloys even in primary aerospace structures to achieve higher performances with lighter components. However, random events such as low-velocity impacts may induce damages that are typically more dangerous and mostly not visible than metals. The

Review and discussion of substantive to revolutionary concepts to enable a commercially viable, societally acceptable supersonic transport. Issues addressed include economic viability, take off noise, sonic boom, emissions and frontier aircraft configurations. Solution spaces include an enabler for most of the issues, which is doubling the lift-to-drag ratio. Approaches in most cases require serious

Since the birth of bio-inspired flapping-wing micro air vehicles, a controversial topic, i.e., whether and to what extent a flapping wing can outperform conventional micro rotors, has existed in the field of micro-to pico-scale unmanned aircraft. However, instead of answering this debate, an alternative idea that combines the flapping-wing and rotary-wing layouts was proposed and has been extensively

The elastic strain energy-driven thin-walled deployable composite structures, characterized by their integration of structure and functionality, have attracted considerable attention in the field of space applications. These structures utilize the stored strain energy accumulated during the folding process to achieve elastic deployment. Significant progress has been made in the understanding of deformation

In response to escalating environmental concerns and stringent economic constraints, there is an urgent need to develop aircraft technologies and configurations that substantially enhance efficiency. A prominent trend in aircraft design aimed at minimizing lift-induced drag, improving fuel efficiency, and mitigating emissions is the adoption of increased wing Aspect Ratio (AR). This paper examines

Trends in space technology development and rapidly increasing traffic in outer space are likely to lead to the emergence of a market for services for the removal of large debris objects to disposal orbits. The commercial benefits of Active Debris Removal missions are possible when multiple objects are removed by a single spacecraft-collector that flies between targets in an optimal sequence, trying

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Recent advances in Artificial Intelligence (AI) and Cyber-Physical Systems (CPS) for aerospace applications have brought about new opportunities for the fast-growing satellite industry. The progressive introduction of connected satellite systems and associated mission concepts is stimulating the development of intelligent CPS (iCPS) architectures, which can support high levels of flexibility and resilience

The utilization of hybrid electric propulsion concept in aviation offers a viable solution to address the limitations posed by the relatively low energy density of batteries in fully electric aviation. These hybrid systems enable the aircraft to achieve a significant range while simultaneously minimizing carbon emissions. While the individual components of a Hybrid Electric Propulsion (HEP) system

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A hypersonic inlet/isolator acts as the “compressor” for scramjet engines through a series of shocks, which induces complex internal flows. This paper comprehensively reviews the recent research achievements, focusing on the shock-dominated internal flow of an inlet/isolator. Considering the specific geometrical feature of the hypersonic inlet, the shock wave/boundary layer interactions (SWBLIs) are

In recent years, the realm of space exploration has undergone a transformative shift, marked by the emergence of a thriving new space economy. This evolution has not only redefined existing space infrastructures and services but has also democratized access to space, accelerating exploration endeavors. At the core of such evolution is additive manufacturing (AM), a groundbreaking technology that has

Standing oblique detonation is a unique pressure-gain combustion phenomenon for hypersonic ramjet propulsion, and its research has been related with supersonic combustion in scramjet engines since its births, for example, absent treatment in its early stage and re-consideration in recent decades. Standing oblique detonations and supersonic combustion share the same features of supersonic chemically-reacting

A review of the literature on the methods for activation of the combustion of metallic fuels, mainly boron-containing ones, as the promising components of composite propellants for ramjets is presented. Some methods and ideas were checked experimentally using a laboratory approach developed for comparing the metallic fuels (MF) of different origin. The approach implies the determination of the set

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This comprehensive study delves into the significance of asteroid research and proposes a systematic classification consisting of seven distinct categories. Initially, a concise definition is presented to differentiate between asteroids, meteorites, and comets, accompanied by a brief exploration of their unique characteristics. Recognizing the valuable scientific insights that these celestial bodies

The vast majority of shock wave–boundary-layer interactions in practical applications like supersonic aircraft intakes are three dimensional in nature. The complex behaviour of such interactions can generally be understood by combining the flow physics of a limited number of canonical cases. The physical understanding of these flow fields developed by numerous investigators over the last half century

Hierarchical structures provide a means to systematically deconstruct an engineering system of arbitrary complexity into its subsystems, components, and physical processes. Model validation hierarchies can aid in understanding the coupling and interaction of subsystems and components, as well as improve the understanding of how simulation models are used to design and optimize the engineering system

A review of research progress in the design of the exhaust system for the scramjet and turbine based combined cycle (TBCC) engine is presented. Firstly, the technical challenges encountered in designing the exhaust system for a hypersonic propulsion system are highlighted and discussed, and the performance parameter definition as well as the theoretical thrust prediction for the exhaust system is introduced

Advanced Air Mobility (AAM) represents a collaborative vision shared by NASA, regulatory agencies, and global industry leaders, aimed at establishing a robust and reliable air transportation ecosystem, which is expected to facilitate safe and efficient movement of both people and cargo within urban, suburban, and regional environments. This paper presents a holistic review and analysis encompassing

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The continued emission of greenhouse gases presents an existential threat to civilization on our planet. Although the aviation sector of the global economy contributes only a small percentage of the total greenhouse gas emissions it will become increasingly important to decarbonize this sector no later than 2050 if the danger of irreversible climate change is to be averted. In this special issue an

Sustainability has recently been identified as the greatest challenge facing the modern aviation field. Given the extreme power and energy characteristics of transport-class aircraft today,achieving sustainability goals across the aviation sector is a tremendous challenge when compared to other modes of transportation. Several key energy carriers have emerged, promising an environmentally sustainable

This paper investigates the potential pathways and associated requirements to meet a goal of net-zero greenhouse gas (GHG) emissions from the US commercial aviation sector by 2050 as outlined in the US 2021 Aviation Climate Action Plan. Aviation traffic (RTK) is projected to grow at an average of 2.0% per annum between 2019 and 2050, suggesting that a progressive and ultimately total decoupling of

The main goal of this paper is to present a vision for the future of aviation. Developing such a vision is always a complex matter, but in times of environmental emergencies and unjustifiable wars it becomes even more difficult. One of the main reasons of this paper is to show that there is still room for advancing clean technology developments and to demonstrate that the aviation sector is ready for

Civil aviation provides an essential transportation network that connects the world and supports global economic growth. To maintain these benefits while meeting environmental goals, next-generation aircraft must have drastically reduced climate impacts. Hydrogen-powered aircraft have the potential to fly existing routes with no carbon emissions and reduce or eliminate other emissions. This paper is

Reducing greenhouse gas emissions has become a priority for civil transport aviation. One of the possible solutions investigated by current aeronautics research is the introduction of electric propulsion, which would drastically reduce greenhouse gas emissions related to flight. This paper addresses this topic in depth; the work is structured in two intertwined parts. The first relates to an extensive

The continuously increasing interest in alternative aircraft propulsion systems is caused by the requirements and demands set by international institutions and government organizations. For instance, nowadays in the European Union, the objective called the European Green Deal seems most demanding. According to this regulation, the members of the European Union should ensure the net zero emission of

The use of fossil fuels, which are employed to supply the energy needs of aircraft, is currently causing severe environmental concerns, placing pressure on the aviation industry and mandating specific action. Sustainable aviation fuels that would lessen the aviation industry's environmental effects are viewed as a potential substitute for fossil fuels. Hydrogen, a clean energy carrier, is regarded

The sustainability of air transport is increasingly studied in relation to climate issues. The objective of this paper is to provide the key elements for assessing whether a given transition scenario for aviation could be considered as sustainable in the context of the Paris Agreement. Addressing this question relies on a broad range of concepts which are reviewed. First, ethical considerations related

From the perspective of aeronautical engineers, this paper gives a systematical summary of the technical aspects of bird flight that should be considered in the analysis and design of flapping unmanned and micro air vehicles (UAVs and MAVs). The relevant aspects include the scaling laws, avian wing geometry, avian wing kinematics, aerodynamics models, computations, and special topics. Instead of extensively