In the past two years of 2023-2024, two space vehicles were inserted into orbits about Sun-Earth Lagrange points, joining eight other spacecraft about the L1 and L2 points. As interest in these points grows and become more populated, the chance for artificial space debris to inflict hazard on the region increases. The Circular Restricted Three-Body Problem (CR3BP) may be used to propagate the motion

The use of multirotors for inspection tasks requires the ability to perform high-precision flights close to the environment, where aerodynamic effects appear and make control of the platform difficult. This paper presents a control solution for multirotors to deal with aerodynamic effects and other disturbances produced at a motor level. It combines the inclusion of a mechatronic system embedded in

The Sun-Earth L1 and L2 Lagrange points offer a unique and advantageous location for missions related to heliophysics, astronomy, and the overall study of the Solar System. As interest in these points grows and becomes more populated, however, the chance for artificial space debris to inflict hazard on the region increases. The Circular Restricted Three-Body Problem (CR3BP) may be used to propagate

This paper investigates the prediction accuracy and time efficiency of two distinct low-fidelity methods for predicting the tonal and broadband noise of a drone rotor in axial and non-axial inflow conditions. These are both derived from an aerodynamic rotor model based on the blade element momentum theory, respectively coupled with a time- and a frequency-domain solution of the Ffowcs Williams-Hawkings

Thermoacoustic instability is a common problem in many kinds of combustors, especially for lean burn combustor. As a classic device for studying the mechanism thermoacoustic oscillations, a Rijke tube was studied numerically and experimentally, and it was demonstrated that the thermoacoustic oscillations can be mitigated by the Micro-second Pulsed plasma discharge. A SIMULINK code was built based on

The cooling effectiveness of various cooling structures for a one-piece strut flame stabilizer is experimentally measured. The flow field and relative pressure loss are analyzed using validated numerical simulations. Three cooling structures are investigated: gas film cooling (GF), impact/slit cooling (IS), and impact/discrete gas film cooling (IDGF). The influence of mass flow ratios ranging from

High-speed thermal jets are widely applied in aerospace and other engineering fields. Compared with cold jets, screech tones in hot jets have higher frequencies and lower intensities. However, there are fewer studies on the screech modes of hot jets. In this paper, large eddy simulations are carried out on underexpanded free jets with different nozzle temperature ratios (NTRs) and nozzle pressure ratios

Surge is a significant concern in compression systems utilizing turbo-compressors as the core component, as it induces violent fluctuations in pressure and flow rate, which can potentially damage the mechanical structure. Surge characteristics can be categorized into temporal and spatial frequencies. This paper presents an experimental study of surge's temporal and spatial frequencies in both a subsonic

This paper aims to develop an intake with balanced wide-speed-range performance for TBCC. A type of simple adjusting mechanism for intake compression section is proposed, which enables contraction ratio (CR) largely varying within 3.60∼7.14 (the change ratio reaches to 98.3%). The CR distribution locates close to ‘Isentropic Limit’ to obtain both good compression ratio and start ability within Mach

Aluminum alloy powder offers a promising approach to regulating propellant performance. A comparative analysis was conducted on the thermal oxidation, ignition, and self-sustaining combustion characteristics of aluminum-nickel alloy and aluminum powder, utilizing synchronous thermal analysis experiments (TG-DSC) and a laser ignition testing system. Subsequently, a series of experiments were conducted

This work focuses on the active aero-visco-elastic flutter control of smart sandwich panels under supersonic airflow by combining viscoelastic materials with variable stiffness composites and surface bonded piezoelectric sensor/actuator layers, exploring variable-order layerwise models based on shear deformation theories. Numerical applications of smart sandwich panels encompass either viscoelastic

The growing demand for more efficient aircraft has made the development of innovative designs critical. Distributed propeller aircraft configurations are among the most promising solutions in this quest for enhanced performance. The objective of this study is to develop an efficient wing design and optimization methodology that accounts for the aerodynamic interaction between the propeller and wing

Considering the limitations of two-dimensional linearized collision models and the challenges in identifying missile guidance law types and parameters in modern aerial combat game, this paper proposes a target evasion strategy suitable for three-dimensional scenarios. This strategy relies solely on information about the missile's motion state and is independent of the missile guidance law types and

Compared to traditional aerodynamic control surfaces, the reaction control system (RCS) offers enhanced control maneuverability for hypersonic vehicles at high flight altitudes with a low-density effect. However, the interaction of double lateral jets in a rarefied nonequilibrium flow yields intricate flow phenomena, markedly affecting the performance analysis of RCS. In this study, the nonlinear coupled

This paper presents a comprehensive overview of the operation and spectral performance of a novel lab-scale afterburning jet noise rig at Virginia Tech. The study involved steady-state operation at relevant Total Temperature Ratios (TTR) of approximately 6, typical for afterburning jets. The flow was discharged through a scaled-down GE F-404 supersonic nozzle, and far-field noise measurements were

Aerospace devices are vulnerable to pyroshock and require testing. The shock response spectrum (SRS) compares shock severity but ignores temporal features. To improve testing reliability, temporal characteristics and their changes during pyroshock propagation need to be studied. In this paper, the shock propagation problem is studied experimentally. Two temporal features, i.e., the effective duration

This paper studies the bearing-based simultaneous localization and affine formation tracking (SLAFT) control problem for fixed-wing unmanned aerial vehicles (UAVs). In the considered problem, only a small set of UAVs, named leaders, can obtain their global positions, and the other UAVs only have access to bearing information relative to their neighbors. To address the problem, we propose novel schemes

One of the main reasons for compressor instability is the corner separation of stators. To address this issue effectively, this research introduces three key innovations: (1) Proposing a novel end-slot design driven by incoming flow momentum; (2) Investigating comprehensively the slot jet mechanism in redistributing blade loading and controlling corner stall; and (3) Validating lower blade count with

Due to the coordinate-invariant nature of traditional eddy viscosity models, it is challenging to accurately predict flows with specific directional influences without modification. The rotation of reference frames or curved wall flows significantly increases the complexity of turbulence, making the accurate prediction of directional turbulent flows crucial, especially for aircrafts which have curved

Carbon fiber reinforced polymer (CFRP) laminates, specifically T700/Epoxy 648, are known for their excellent mechanical properties in both high and low temperatures, making them suitable for spacecraft structures. This study investigates the mechanical behavior of CFRP laminates with various lay-up designs through quasi-static and dynamic mechanical tests. The laminates demonstrated linear behavior

The efficiency of Boundary Layer Ingesting (BLI) propulsion systems is significantly influenced by the ingested boundary layer flow. This paper examines a typical BLI inlet configuration, using validated numerical simulations to analyze how boundary layer shape factors influence the inlet's internal flow and performance. The results show that increasing the shape factor worsens inlet performance, leading

Plug nozzle of a single-stage-to-orbit launch vehicle moves through continuum to rarefied regime, as it approaches high altitudes. Despite multiple studies on plug nozzle flows in the rarefied regime, there is significantly less work that compares continuum and rarefied flows through plug nozzles. Even the works that conducted such comparative analysis did not consider the effect of varying nozzle

Unmanned Aerial Vehicles (UAVs) have become increasingly integral across diverse sectors, necessitating accurate power consumption modeling to optimize flight operations and ensure reliability. Traditional approaches often fail to capture the intricate, non-linear dynamics between operational parameters and power usage. This study introduces deep learning techniques, including RNN, GRU, LSTM, Bi-LSTM

The global stabilization problem is revisited for the circular orbit spacecraft rendezvous system with actuator saturation. The linearized relative motion equation transformed into its Luenberger canonical form. It is noted that the system decomposed into a cascade of neutral stable linear systems, and bounded linear state feedback controllers for subsystems are designed respectively based on the absolute

In the development of electric aircraft, due to the use of Distributed Electric Propulsion (DEP), not only the classic wing flutter but also the propeller whirl flutter needs to be considered for wing structural design. To this end, this paper proposes an aeroelastic optimization method within the framework of an in-house tool named PROTEUS, which enables the preliminary design of DEP wing laminates

As the applications of multiple unmanned aerial vehicle (multi-UAV) systems increasingly expand, achieving formation maintenance while ensuring safety becomes a critical requirement. Existing methods still face difficulties in dealing with complex environments with unknown and dynamic obstacles. To this end, we propose a flexible multi-UAV formation control method that is based on a model-data hybrid-driven

Ramjet propulsion is often favored for powering supersonic vehicles cruising at speeds exceeding Mach 3. Despite the relatively simple geometric design of these engines compared to turbo-based alternatives, the complex flow physics involved makes their design and optimization challenging. Hence, the design and performance analysis of ramjet engines are crucial to ensure that the propulsion system meets

This paper investigates the aerodynamics and aeroacoustics of a pair of rotors within the “Radiation and Propagation for Multirotor Systems” project from the Group for Aeronautical Research and Technology in Europe (GARTEUR) Action Group 26. The study employs validated high-fidelity computational fluid dynamics (CFD), the in-house Helicopter Multi-Block Solver 3 (HMB3), to investigate a pair of dual-bladed

This paper introduces a versatile, passive-landing system designed for various landing operations such as planetary exploration missions, emergency landings of unmanned aerial vehicles (UAVs), and so on. The system leverages energy and momentum exchange mechanisms, incorporating two spring units and a detachable flyaway component to ensure smooth and safe landings. Initially, the kinetic energy of

The number of spacecraft and space debris, particularly in low Earth orbit, is rapidly escalating, heightening the demand for rational and effective satellite allocation strategies to alleviate the strain on satellite monitoring and tracking systems. In this paper, a clustering scheduling strategy is proposed for satellites equipped with sensors tasked with monitoring a substantial amount of space

To study the influence of strut and pulsed injection on flame stabilization in a kerosene-fueled scramjet, experiments have been carried out at the China Aerodynamics Research and Development Center. Wall pressure measurements, high-speed photography, and CH* luminosity imaging have been used to investigate the flow structure and flame development under different injection modes. The results of the

Spectral proper orthogonal decomposition, a data-based decomposition technique, was performed to extract key spatiotemporal coherent structures from large-eddy simulation data. Both velocity and vorticity were decomposed to identify the dominant unsteady features around the near-tip region. Four operating conditions for two different Reynolds numbers, with and without tip clearance were investigated

As the aerospace industry continues to advance, the demand for round-trip transportation between Earth and space, as well as deep space exploration missions, is increasing. The mechanical deployable reentry vehicle, a complex multidisciplinary system, experiences parameter coupling between trajectory design and aerodynamic simulation. The calculation of trajectory and the design of aerodynamic layout

A three-dimensional cooperative surrounding and capturing guidance (3D-CSCG) is proposed for the cooperative interception against a superior target in the fighter aircraft's self-protection. The interceptors with lower velocity and inferior acceleration compared to the target need to satisfy constraints including impact angle, cooperation time and limited overload. The 3D-CSCG is designed to enable

Air-cooled flameholder is a credible solution for restraining the increasingly raised inlet temperature and operation cycle of advanced afterburner/ramjet combustors. In previous study, the effects of cooling jets on the flow and cooling film characteristics of an air-cooled integrated flameholder (coupled with wall and strut parts) have been revealed by numerical analysis. Furthermore, this work aims

To effectively suppress flow separation in the corner regions of a compressor, improve aerodynamic performance, and enhance distortion tolerance, this study focuses on a single-stage high-load transonic axial flow compressor and introduces a novel and effective unconventional stator design known as an alternating stator (AS) vane layout. This study examines the relationship between the AS layout and

This paper presents a comprehensive framework for offline optimization of tuning parameters in unmanned aerial vehicle (UAV) flight controllers. The framework uses system identification to create a simplified flight dynamics model, followed by control law matching to ensure the simulated controller's output closely replicates real-world autopilot commands. The optimization phase employs genetic algorithms

The thermal deformation of structure in non-uniform thermal environment in space is a critical factor affecting the imaging accuracy of remote sensing satellite. In this study, the thermal deformation theory of near-zero warping sandwich structure under non-uniform temperature field is established. A high-fidelity prediction method based on CT scanning and reconstruction of structural defects is proposed

To investigated the mechanism of flow loss occurs in gas-turbine exhaust volute, comprehensive analysis was conducted based on the traces of parametric optimizations. An original volute was parameterized by depicting the core-part with 6 parameters. Concerning the coefficients of total pressure loss and static pressure recovery, the volute was optimized, as a start of the investigation, by Particle

In the wind tunnel virtual flight test (WTVFT), the translational motion of the model is constrained to have only free rotational motion. As a result, the motion data measured in the WTVFT differ from those measured during free flight. If the aerodynamic parameter identification is performed directly via the test data from the WTVFT, the identification results differ from those obtained on the basis

The thermoacoustic instability characteristics in a variable-length annular combustor fueled by ammonia-methane were investigated in the present work, focusing on the effects of ammonia enrichment on various instability modes. A Helmholtz solver was employed to provide a proper estimate of the mode frequencies. The experimental results presented that instability mode changed from the Helmholtz to the

The combustion characteristics of a gaseous hydrogen fueled scramjet combustor were experimentally investigated through single-shot micro-pulse detonation engine (μPDE) operations across a range of fuel injection pressures and corresponding equivalence ratios. This study utilized a lab-scale direct-connect scramjet combustor integrated with a μPDE, designed to simulate flight conditions at Mach numbers

In our recent experimental investigation, the feasibility of a liquid-kerosene-fueled air-breathing/ramjet rotating detonation engine featuring a cavity-based annular combustor has been experimentally demonstrated. Achieving stable operation and organized detonation combustion within the rotating detonation combustor presents significant challenges that demand further investigation. Thus, this study

The backward shift of the aerodynamic center and insufficient morphing capability are critical design bottlenecks of traditional rotary variable-sweep wings. This paper presents a new shear variable-sweep morphing form that reduces the backward shift of the aerodynamic center by allowing the leading edge of the wing to slide forward. The shear variable-sweep wing (SVSW) with this morphing form enables

Wind tunnel tests are commonly used to visualize the trailing vortices, but tests involving advanced optical measurement techniques can be costly. Camera-based experiments are more affordable, but the low visibility caused by smoke particles and limitations of the upright view make vortex characterization and quantification challenging. In this paper, the proposed perspective upright correction allows

Quickly redesigning hypersonic aircraft structures and accurately evaluating the full-field response is crucial and significantly challenging. Therefore, this paper proposes a novel data-driven scheme, GD-DORGP, which encompasses a non-parametric adaptive characterization method for freely designing complex geometric deformations (GD) and dual order-reduced Gaussian Process (DORGP) emulators to predict

A better understanding of gas-solid flow in the pneumatic conveying of dense powders is an essential prerequisite for effective design and operation of conveying systems in powder fueled ramjets. This paper presents a resistance modified model applicable to the dense-phase powder conveying in gas-driven piston powder feeding system based on Two-Fluid Model (TFM), and the dynamic grid techniques related

Circumferential distortion has been a concern since the early development of aeroengines, typically leading to a decrease in stability and efficiency. This paper experimentally investigates the effect of circumferential distortion on a low-speed axial fan and evaluates the potential of foam metal casing treatment (FMCT) to improve the stall margin. Distortions with different intensities were modeled

This article explores robust adaptive motion control for a cable-driven aerial manipulator in the presence of input saturation. The investigation begins by considering the physical attributes of the aerial manipulator and establishing a kinematic and dynamic model of the system with lumped disturbances. Following this, a new control law is formulated using the parameter adaptive technique, where the

Data assimilation in turbulent fields serves as a crucial means of acquiring high-fidelity training data for turbulence modeling. Prevailing data assimilation methodologies predominantly concentrate on individual experimental observations, while little attention has been paid to the influence of heterogeneous experimental data types on assimilation outcomes, and identifications are rarely made to find

Soft air refueling has become the most widely used unmanned autonomous refueling method for air forces in various countries due to its simple, reliable, and convenient advantages. The bow wave effect generated by the oil receiver is the main reason for docking failure. Establishing a bow wave model and accurately predicting the docking effect under its influence has become a key focus of research in

In this paper, an asymmetric full-state constrained attitude control method for a flexible agile satellite with multiple disturbances and uncertainties is proposed. Both the attitudes and angular velocities of the flexible agile satellite are guaranteed in the asymmetric/symmetric bounds by utilizing the time-varying integral barrier Lyapunov function (TVIBLF) and constant integral barrier Lyapunov

Effective geometric parameterization is crucial in aerodynamic shape optimization for enabling flexible surface deformation while maximizing design space coverage. This paper studies the impact of different geometric forms (closed and open curves) on the effectiveness of Proper Orthogonal Decomposition (POD) geometric parameterization and explores the information of physical features contained in the

This study examined the atomization characteristics of direct injection nozzles under high-temperature, large-Mach inflow conditions using a high-speed camera. The effect of inflow conditions on fuel breakup length, fuel concentration field, and particle size spatial distribution was quantitatively analyzed by using image processing techniques. Experimental results indicate the following: 1) When the

This study addresses the challenges of designing high-efficiency compressors for long-endurance, high-altitude unmanned aerial vehicles (UAVs) under low Reynolds number (Re) and high load conditions, exploring the aerodynamic performance limits of compressor blades under extreme conditions. The research integrates advanced numerical simulations, experimental methods, and deep learning technologies

To address the asymmetric flow field of the flying wing under cross-flow conditions at high angles of attack, dual synthetic jet actuators (DSJAs) are positioned at the leading edge of the windward side. DSJ control effectively affects the flow separation structure on the windward side, thereby enhancing leading-edge suction. This leads to both lift enhancement and drag reduction. Furthermore, it strengthens

For the right design of nanosystems with integrated piezoelectric transducers and materials, it is crucial to understand the electro-mechanical coupling factor. Considering this, this work determines the influence of placement and dimension of piezoelectric patch on the vibrations of circular sandwich sector nanoplate coupled with an electrically layer. The core of the current nanostructure is made

Utilizing digital tools for satellite optimization design is vital for supporting decision-making in the actual engineering of satellites. The higher the accuracy of the simulation model, the more precise the satellite performance evaluation, and the more valuable the optimization results. Traditional heuristic algorithms have been successful in optimizing satellite parameters but face challenges when

This study proposes a novel vortex-controlled flameholder (VCF) to enhance the combustion performance, particularly the lean ignition and blowout characteristics of afterburners in advanced aircraft engines across a wide range of operating conditions. Additionally, both experimental and numerical investigations were conducted to explore the effects of the cavity structure on the flow field, lean ignition

To enhance the performance of conventional ADN-based catalytic ignition thrusters, a plasma-assisted thruster was developed employing coaxial cylinder electrodes within a 1N-class thruster configuration. Steady-state ignition tests conducted on the experimental bench, demonstrated high repeatability in an atmospheric environment. High-speed imaging and proper orthogonal decomposition (POD) analysis