Numerical simulation was carried out to study the influences of blade-bowing designs based on a highly loaded cascade with large turning angle, while the compound bowing design showed much lower endwall loss than the conventional design in this study. Generally, it showed that the increased turning angle would strengthen the adverse pressure gradient on the suction surface, so the side effect of negative

Classical approach to conceptual and preliminary design in aerospace sciences reaches limits. To go further and achieve better, competitive results’ use of optimization methods becomes mandatory. The trend is clearly visible in professional software for simulations equipped with optimization tools, which was not standard just decade ago. Many examples of multidisciplinary optimization were shown, especially

Focusing on the long-distance rapid cooperative rendezvous of two spacecraft under finite continuous thrust, this paper proposes a practical strategy for space operation using multiple specific-direction thrusts. Based on the orbital dynamic theory and Pontryagin’s maximum principle, the dynamic equations and optimal control equations for radial, circumferential, and normal thrust are determined. The

Technology of photovoltaic cells and lithium batteries is developing rapidly. As a result, more and more attempts are made to build solar high altitude long endurance airplanes. Unfortunately, data on altitude impact on photovoltaic cells and batteries performance are not easily available. Moreover, acquisition cost of cells is still high. As a result, high altitude long endurance airplanes design

Tailsitter unmanned aerial vehicles are utilized extensively nowadays since they merge advantages of both fixed-wing unmanned aerial vehicles and rotary-wing unmanned aerial vehicles. However, their attitude control suffers from unknown nonlinearities and disturbances due to the wide flight envelope. To solve the problems, a robust attitude controller based on a newly designed flying-wing tailsitter

Aerothermoelastic analysis of hypersonic vehicles is a complex multidisciplinary coupling problem. Thus, accurate modeling of varying disciplines with low computational cost is necessary. This work developed a tractable approach-based reduced-order modeling technology to solve the radiative thermal transfer problem in a hypersonic simulation. A method that combines proper orthogonal decomposition and

Aiming at the problem of missile attacking ground target in pitch plane, combined with a composite fast nonsingular terminal sliding mode, a new adaptive finite-time stable guidance law with attack angle constraint is designed based on the second-order sliding mode control. The improved extended state observer is used to estimate the uncertainties and compensate the control quantity, and the dynamic

An integrated celestial navigation scheme for spacecrafts based on an optical interferometer and an ultraviolet Earth sensor is presented in this paper. The optical interferometer is adopted to measure the change in inter-star angles due to stellar aberration, which provides information on the velocity of the spacecraft in the plane perpendicular to the direction of the observed star. In order to enhance

Recently, fluidic thrust vectoring control is popular for micro space launcher propulsion systems due to its several advantages, such as fast dynamic responsiveness, better control effectiveness, and no moving mechanical equipment. Counter-flow thrust vectoring control is an especially effective technique by utilizing less suction flow to control the mainstream deflection flexibly. In the current work

The request of even more stringent restrictions, regarding efficiency and environmental impact of industrial components, determines an optimized use of primary energy but also entails the design of more lightweight, smart and flexible devices, able to adapt their operation as a function of several different inputs. In this framework, the use of a fascinating class of metallic materials, called Shape

This paper presents the optimization of multi-element aerofoil for the LAR-3 Puffin -- STOL light transport aircraft concept proposal. Based on the geometry and aerodynamic characteristics of the well-known and proven in flight three-segment NACA 63A416 aerofoil, the authors explore the possibility of enhancing its high-lift performance by the movement of slot and flap position in extended (deployed)

This article investigates the design of a novel nonlinear robust adaptive control architecture to stabilize and control an airplane in the presence of left-wing damage. Damage effect is modeled by considering the sudden mass and inertia changes, center of gravity, and aerodynamic variations. The novel nonlinear control algorithm applies a state predictor as well as the error between the real damaged

This article presents L1 adaptive control scheme for vertical flight control of helicopter. Linear controller is designed as baseline controller to provide preliminary improvement in performance and robustness. Considering the existence of uncertainties and disturbances, we propose L1 adaptive controller with modified piecewise constant adaptation law to augment the baseline controllers. Further, the

Constructal T-shaped porous fins transfer better heat compared to the rectangular counterparts by improving the heat flow through the low resistive links. This type of fins can be used in aerospace engines which demand faster removal of heat without adding extra weight of the overall assembly. Here, in this study, three powerful nature-inspired metaheuristic algorithms such as particle swarm optimization

The failure of aeroengine rotor will cause a great threat to the flight safety. A new risk assessment model to assess the possibility and severity of failure of aeroengine rotor is presented addressing the problems that its failure samples are not sufficient and that early potential failures are not easy to recognize. The key point of this model is to determine the risk mechanism with diverse failures

A simple estimation method of momentum coefficient of synthetic jet actuator has been proposed. Flow separation over an airfoil can be suppressed sufficiently with the estimated momentum coefficient. At a certain angle of attack (AOA), momentum deficit of boundary layer at front of separation point can be quantified based on Bernoulli's theorem. The function of synthetic jet actuator is deemed to be

This paper aims to design a novel experimental platform with multiple testing possibilities on different individual performance parameters and different rotary propulsion systems. Three mechanic swingarms were constructed to separately and simultaneously test the rotor(s) and shroud, so that the interactions among different components can be involved. Based on it, measurements on the total thrust,

In fatigue test, the fatigue life of metal components is affected by many factors, such as test temperature, stress ratio and loading frequency. In order to study the influence of temperature on fatigue life of bolted joints, thermal stress and fast coefficient are introduced. A numerical method of fatigue crack initiation life is proposed based on Manson-Coffin strain fatigue formula. The crack initiation

Typically, the evaluation of nacelle drag in preliminary design is required to find an overall optimum engine cycle and flight trajectory. This work focuses on the drag characteristics of aero-engine nacelles with separate jet exhausts. The main body of analysis comes from 3D numerical simulations. A new near-field method to compute the post-exit force of a nacelle is presented and evaluated. The effects

A regional, turbofan-powered, 72-passenger, transport aircraft with very high aspect ratio truss-braced wings is developed with an affordable methodology from an existing 52 passenger, conventional twin-turboprop aircraft. At first, the ration behind the selection of the truss-braced wing configuration is discussed. Next, the methodologies for the sizing, weight, aerodynamics, performance, and cost

Stiffened panel as a kind of thin-walled component is widely used in aircraft. A novel stiffened panel manufacturing method has been proposed that the plate is bent into designed shape first with multi-point forming method and then milled into integral panel. However, in the bending process, springback is a great issue. In this paper, an analytical method is proposed to predict the springback of the

A new robust quaternion Kalman filter is developed for accurate alignment of stationary strapdown inertial navigation system. Most fine alignment algorithms have tried to estimate the biases of gyroscopes and accelerometers to reduce the errors of the alignment process. In stationary platforms, due to fixed inputs for sensors, the summation of various errors such as fixed bias, misalignment, scale

Critical inlet pressure (CIP) is a key parameter for ensuring the long life and steady operation of aircraft piston pumps. In the past, this parameter was determined through experimental methods that had drawbacks such as a long duration and narrow application range. To identify an alternate approach that can be substituted for the traditional approach, a numerical model for determining the CIP that

The structure and dynamic of the shock train in a mixing duct are investigated experimentally in a supersonic air breathing wind tunnel. High-speed schlieren technique and pressure measurements are utilized for the data acquisition. Nozzle clapboards are applied to separate the incoming flow into upper secondary flow, primary flow, and lower secondary flow. The Mach number of all incoming flows is

Several well-established best practices and reliable tools have been developed along the years to support aircraft conceptual and preliminary design. In this context, one of the most widely used tool is the Matching Chart (MC), a graphical representation of the different performance requirements (curves representing the thrust-to-weight ratio (T/W) requirement as function of the wing loading (W/S))

When modeling an aeroengine control system, effects of fuel metering unit are neglected or oversimplified, which most probably leads to unreliable simulation or experimental results. In order to well understand influences of fuel metering unit on performance of an aeroengine and to enrich the component-level model of a turboshaft aeroengine, a stepping motor controlled fuel metering unit is examined

Fuel efficiency improvement and harmful emissions reduction are the main motivations for the development of gas turbine combustors. Numerical computational fluid dynamics (CFD) simulations of these devices are usually computationally expensive since they imply a multi-scale problem. In this work, gaseous non-reactive unsteady Reynolds-Averaged Navier–Stokes and large eddy simulations of a gaseous-fueled

The present study presents a new nonlinear unsteady aerodynamic model to investigate the aeroelastic behavior of a self-sustained oscillating rigid airfoil. Here the unsteady Euler equations are considered simulating inviscid compressible transonic flow over an oscillating airfoil. In regard to providing boundedness criteria, a high-order technique based on a normalized variable diagram scheme has

This paper presents a method to use the Bezier curve to rapidly generate three-dimensional low-thrust trajectories, which can provide a suitable initial approximation to be used for more accurate trajectory optimal control tools. Two missions, from Earth to Mars and the asteroid Dionysus, are considered to evaluate the performance of the method. In order to verify the advantages of this method, it

The process of empirical models evaluation is at the core business of experimental flight-testing data analysis. Accurate and convenient flight-testing of helicopter engine(s) available power is crucial for predicting the total helicopter performance. Common practice in estimation of in-flight helicopter gas turbine engine power consists of a reduction of flight-test data into simplistic single-variable

In order to ensure flight safety, the stall test is one of the most important steps in the airworthiness certification phase of civil aircraft. The twisted-swept fan is one of the most important components of the high bypass ratio engine. The unsteady flow field of the fan rotor stall condition is obtained by numerical simulation. At the same time, the time series flow field data of the stall condition

The aircraft power supply system provides power for all the electrical equipment on the aircraft. Its normal operation is the key to ensure the safe flight of the aircraft. So, identifying the hazards in aircraft power supply system is necessary and critically important. In this paper, a hazard identification system for APSS based on the combined simulation of SIMPLORER and MATLAB is proposed. First

In this work, a 3D numerical study on the influence of the spanwise distribution of tubercles on a unmanned aerial vehicle wing is presented. The idea of using tubercles in aeronautics comes from the humpback whale (Megaptera novaeangliae) which has a characteristic flipper, with a spanwise scalloped leading edge, creating an almost sinusoidal shape, consisting of bumps called tubercles. The whale

Casing treatment is an effective way to improve the stable working margin of the compressor and plays an important role in ensuring the stable and safe work of the compressor. On the premise that the numerical results are in agreement with the experimental values, the paper study on a new type of the self-circulating casing treatment with double-bleed ports structure was carried out on the NASA rotor

Novel propulsion systems and their synergistic integration with the airframe are expected to play a key role in pursuing aviation’s challenging long-term sustainability targets. The recuperation of aircraft skin friction-induced flow momentum via Boundary Layer Ingesting (BLI) propulsion – the so-called wake-filling propulsion integration – is considered to be a technological enabler for strong improvements

Experimental investigation on two rectangular wings with NACA0012 and NACA4415 profiles is performed at different Reynolds numbers to understand their aerodynamic behaviours at a high α regime. In-house developed numerical code VLM3D is validated using this experimental result in predicting the aerodynamic characteristics of a rectangular wing with cambered and symmetrical wing profile. The sectional

This paper deals with the structural response and wall thickness design of pulse detonation combustor. The pulse detonation combustor is a chamber with cylindrical shell structure, which is loaded with internal moving detonation pressure and thermal load. Much higher strain and stress can be excited under moving pressure load than static load. How to choose the attenuation coefficient during detonation

Abdolbaghi B, Shahram EH and Adel M. Experimental and analytical analysis of aerodynamic lift of an ornithopter at low and high angles of attack. Proc IMechE, Part G: J Aerospace Engineering 2019; 233: 2023–2031. DOI: 10.1177/0954410018771175

In the present paper, an efficient pseudospectral method for solving the Hamiltonian boundary value problems arising from a class of switching optimal control problems is presented. For this purpose, based on the Pontryagin's minimum principle, the first-order necessary conditions of optimality are derived. Then, by partitioning the time interval related to the problem under study into some subintervals

This paper studies the dynamic retrieval process of a towed target system under perturbation by simulating the reel-in operation under the towing airplane’s wake and atmospheric turbulence. To settle the computational problem of cable tension, the constant-length method is proposed to transform this variable-mass problem into a constant-length problem based on a mass-spring model that discretizes the

Space Sled is a device for providing controlled linear acceleration stimuli in the microgravity environment of orbital flight. The scientific objectives of the experiments which used Space Sled on the D-1 Spacelab mission were to study aspects of otolith organ (that is, that part of the inner ear which transduces linear accelerations) function and adaptation in weightlessness. Space Sled comprises