Aircraft Performance Research Articles

Optimizing the Performance of different Airfoils at Various Angles of Attack through CFD Simulation

This study specifically examines the NACA 0012, NACA 4412, and NACA 2412 airfoil profiles using ANSYS FLUENT. By simulating the flow over these airfoils, we can comprehensively explore the impact of the angle of attack on lift and drag coefficients. Notably, the study reveals that the angle of attack directly influences lift force, with a critical angle beyond which the aircraft may stall. Thus, the research underscores the importance of maintaining an optimal angle of attack to avoid turbulence and optimize aircraft performance. The aerodynamics of airfoil shapes play a crucial role in the performance and safety of aircraft. Understanding airflow characteristics over airfoils, particularly concerning the critical angle of attack, is paramount in achieving optimal lift while avoiding stalling. This paper delves into the shift of the separation point on the upper surface of most airfoil shapes, emphasizing the shift from the trailing edge to the leading edge as the angle of attack increases. Stalling becomes a critical concern beyond the critical angle of attack, necessitating comprehensive research to enhance aircraft performance and safety.

Detection Transformer with Multi-Scale Fusion Attention Mechanism for Aero-Engine Turbine Blade Cast Defect Detection Considering Comprehensive Features.

Casting defects in turbine blades can significantly reduce an aero-engine's service life and cause secondary damage to the blades when exposed to harsh environments. Therefore, casting defect detection plays a crucial role in enhancing aircraft performance. Existing defect detection methods face challenges in effectively detecting multi-scale defects and handling imbalanced datasets, leading to unsatisfactory defect detection results. In this work, a novel blade defect detection method is proposed. This method is based on a detection transformer with a multi-scale fusion attention mechanism, considering comprehensive features. Firstly, a novel joint data augmentation (JDA) method is constructed to alleviate the imbalanced dataset issue by effectively increasing the number of sample data. Then, an attention-based channel-adaptive weighting (ACAW) feature enhancement module is established to fully apply complementary information among different feature channels, and further refine feature representations. Consequently, a multi-scale feature fusion (MFF) module is proposed to integrate high-dimensional semantic information and low-level representation features, enhancing multi-scale defect detection precision. Moreover, R-Focal loss is developed in an MFF attention-based DEtection TRansformer (DETR) to further solve the issue of imbalanced datasets and accelerate model convergence using the random hyper-parameters search strategy. An aero-engine turbine blade defect X-ray (ATBDX) image dataset is applied to validate the proposed method. The comparative results demonstrate that this proposed method can effectively integrate multi-scale image features and enhance multi-scale defect detection precision.

Structural design and material comparison for aircraft wing box beam panel

This paper aims to present a comprehensive investigation to obtain the structural calculations needed to design a rigid panel of aluminum alloy for the wing box beam of an ATR 72–500 aircraft. For this design process, several types of materials, including composites like CFRP, are considered so it is possible to compare the actual existing part made of aluminum to them, thus checking the advantages these new materials offer. The research presents an introduction to structural design and provides a study of the relevant literature. The aircraft's principal characteristics and performance abilities were collected so that structural loads can be computed. Research used several methods, a design using conventional methods, applying the theory of elasticity is performed using the Theory of Farrar, allowing us to obtain an analytical solution to the problem, followed by checking the obtained results using Ansys FEM software combined with the parts being designed with CATIA. Furthermore, this same panel is calculated using composite materials instead of conventional aluminum, allowing us to compare both solutions. This research shed light on the intricate process of aircraft structural design, materials selection, and calculation methodologies, highlighting the ongoing pursuit of new and advanced materials. This paper makes clear that using composite materials presents several advantages over traditional ones, allowing for lighter, safer, more fuel-efficient, and more sustainable aircraft. The use of composite materials in the construction of airplane structures is driven by many factors. The results show that the chosen composite materials reduce weight, are durable, have low maintenance requirements, reduce noise, enhance fuel economy, and are resistant to corrosion.

A System of Systems Framework for Strategic Cargo Airlift Using Agent-Based Modelling

The effective transport of cargo across the globe by aircraft, termed strategic airlift, is foundational to the success of humanitarian aid/disaster relief (HA/DR) missions and even military operations. Due to the variable extremity of these events, it is essential for aircraft and operations to be designed with a high resilience, factoring in performance in a plethora is scenarios. This work aims to provide a framework that enables the coupling of aircraft, fleet and concepts of operations (CONOPS) design to a mission effectiveness in a strategic cargo airlift. Through agent-based modelling, the complex interaction and emergent behaviors of the different systems in the dynamic airlift environment is better captured and evaluated. Unexpected events, such as cargo requirement reformulation, aircraft servicing and changing airbase accessibility, are employed to emulate the dynamic and spontaneous nature of rapid cargo airlift missions. The impact of these events is stochastically modelled, promoting an analysis of a variety of scenarios. By creating a theoretical disaster relief mission, a trade-space exploration is conducted so that aircraft designs and operational objectives can be evaluated for their mission effect. The framework demonstrates the ability to evaluate aircraft and operational performance holistically, enabling a more robust design procedure for a variety of potential design scenarios and metrics.

Probabilistic Design Method for Aircraft Thermal Protective Layers Based on Surrogate Models

In this study, a probabilistic method was proposed for an aircraft’s thermal protective layers. The uncertainties of material properties, geometric dimensions, and incoming flow environments were considered for the design inputs. To accelerate the design efficiency, Latin hypercube sampling and surrogate models were built based on finite element method calculations to enhance the simulation efficiency. Thus, the Monte Carlo method can be implemented with such a fast simulation method and produce a massive number of samples for the uncertainty quantification and sensitivity analysis, exploring their impact on the back temperature of the thermal protection layer. Compared to the deterministic method with the extreme deviation design, the probabilistic design yields a weight reduction of 15.61%. This indicates that probabilistic design is an efficient approach to enhance the performance of aircraft and reduce the overall weight of the aircraft. The general goal of this study is to provide a new design method for the coating film of thermal protection systems by considering multiple sources of uncertainties.

A Review of Novel and Non-Conventional Propulsion Integrations for Next-Generation Aircraft

The aim of this review paper is to collect and discuss the most relevant and updated contributions in the literature regarding studies on new or non-conventional technologies for propulsion–airframe integration. Specifically, the focus is given to both evolutionary technologies, such as ultra-high bypass ratio turbofan engines, and breakthrough propulsive concepts, represented in this frame by boundary layer ingestion engines and distributed propulsion architectures. The discussion focuses mainly on the integration effects of these propulsion technologies, with the aim of defining performance interactions with the overall aircraft, in terms of aerodynamic, propulsive, operating and mission performance. Hence, this work aims to analyse these technologies from a general perspective, related to the effects they have on overall aircraft design and performance, primarily considering the fuel consumption as a main metric. Potential advantages but also possible drawbacks or detected showstoppers are proposed and discussed with the aim of providing as broad a framework as possible for the aircraft design development roadmap for these emerging propulsive technologies.

An aircraft assembly process formalism and verification method based on semantic modeling and MBSE

The aircraft assembly system is highly complex involving different stakeholders from multiple domains. The design of such a system requires comprehensive consideration of various industrial scenarios aiming to optimize key performance indicators. Traditional design methods heavily rely on domain expert knowledge using documents to define assembly solutions which are later verified through simulations. However, these document-centric approaches cannot provide graphical notations for engineers to efficiently understand the entire assembly process. Moreover, it is difficult to analyze the performance of the designed assembly processes using simulations since the simulation models have to be developed based on the documents manually rather than be generated automatically from the design models. In this paper, a semantic-driven approach is proposed to support aircraft assembly process formalism and performance analysis. First, meta-models of aircraft assembly processes are developed based on SysML and discrete-event simulation models using a semantic modeling language named KARMA. Then an application ontology is defined for generating semantic models from KARMA architecture models to capture domain knowledge, system requirements and simulation model information of the aircraft assembly process. A model transformer is developed to transform the KARMA models to discrete-event simulation models based on the application ontology. Then the generated simulation models are executed to obtain the simulation results for verifying the designed assembly process. Finally, the obtained simulation results are used to support decision-making of selecting the optimal aircraft assembly process. A case study is conducted to verify the proposed method.

Aerodynamic Exergy-Based Analysis and Optimization of the Generic Hypersonic Vehicle Using FUN3D

The development of future novel aircraft concepts requires a holistic approach to vehicle design, analysis, and optimization. Aircraft designers can no longer consider components individually as systems become more interconnected and multidisciplinary. Hence, a new approach to aircraft design and a new way to measure the performance of aircraft are needed. A novel approach to aircraft design is the use of exergy methods that can evaluate typically disparate systems using a universal measure of performance mapped to global system performance. This paper introduces a new functional and its adjoint gradient in FUN3D to determine aerodynamic exergy destruction rates. The functional is verified using the Oswatitsch relationship by comparing it to native, surface-based drag coefficients. The adjoint gradient is verified using the FUN3D native complex step method, and discrete agreement is demonstrated for flowfields and geometric derivatives. The new functional is then used for aerodynamic exergy-based analysis and optimization of the generic hypersonic vehicle. An inverse design problem is conducted first to verify the design optimization framework. Finally, a planform and airfoil aerodynamic inviscid exergy optimization of the GHV is conducted, improving exergy destruction rates by 7.1% while making substantial improvements to the cruise trim characteristics of the vehicle.

Path Planning for Fixed-Wing Unmanned Aerial Vehicles: An Integrated Approach with Theta* and Clothoids

Unmanned Aerial Vehicles (UAVs) have emerged as a compelling alternative to manned operations, offering the capability to navigate hazardous environments without risks for human operators. Despite their potential, optimizing UAV missions in complex and unstructured environments remains a pivotal challenge. Path planning becomes a crucial aspect to increase mission efficiency, although it is inherently complex due to various factors such as obstacles, no-fly zones, non-cooperative aircraft, and flight mechanics limitations. This paper presents a path-planning technique for fixed-wing unmanned aerial vehicles (UAVs) based on the Theta* algorithm. The approach introduces innovative features, such as the use of Euler spiral, or clothoids, to serve as connection arcs between nodes, mitigating trajectory discontinuities. The design of clothoids can be linked to the aircraft performance model, establishing a connection between curvature constraints and the specific characteristics of the vehicle. Furthermore, to lower the computational burden, the implementation of an adaptive exploration distance and a vision cone was considered, reducing the number of explored solutions. This methodology ensures a seamless and optimized flight path for fixed-wing UAVs operating in static environments, showcasing a noteworthy improvement in trajectory smoothness. The proposed methodology has been numerically evaluated in several complex test cases as well as in a real urban scenario to prove its effectiveness.

Exploration of optimal control based surrogate modeling as a basis for fuel efficient 4D aircraft routing on graphs

AbstractFuel efficient coordination of aircraft operations in the Terminal Maneuvering Area of large airports can contribute to the reduction of the environmental impact of air traffic. To exploit the full potential of the air traffic system, coordinated routing in the Terminal Maneuvering Area, runway assignment and scheduling need to be optimized considering detailed models of the aircraft dynamics and performance. Due to the inhomogeneous nature and level of detail of these combined discrete and continuous decision problems, the optimization of the overall operations poses significant challenges. As part of an integrated approach to the solution of this hybrid problem, this work explores the generation of surrogate models for the fuel consumption of individual aircraft using optimal control methods to exploit the physical capability of the aircraft within an operationally permissible envelope. The surrogate models approximate the predicted fuel consumption of a given point-mass aircraft model on short generic trajectory segments. The trade-off between flight duration and fuel consumption on such segments is analyzed, focusing on the influences of initial aircraft mass, altitude, distance, mean climb angle, along-track wind velocity and linear wind shear. An extensive description of the optimal control-based data generation and surrogate modeling methodology is followed by a discussion of the effects of parameter variation. Based on an illustrative case study, the applicability of the approach is critically analyzed.

Airfoil friction drag reduction based on grid-type and super-dense array plasma actuators

To improve the cruise flight performance of aircraft, two new configurations of plasma actuators (grid-type and super-dense array) were investigated to reduce the turbulent skin friction drag of a low-speed airfoil. The induced jet characteristics of the two actuators in quiescent air were diagnosed with high-speed particle image velocimetry (PIV), and their drag reduction efficiencies were examined under different operating conditions in a wind tunnel. The results showed that the grid-type plasma actuator was capable of producing a wall-normal jet array (peak magnitude: 1.07 m/s) similar to that generated in a micro-blowing technique, while the super-dense array plasma actuator created a wavy wall-parallel jet (magnitude: 0.94 m/s) due to the discrete spanwise electrostatic forces. Under a comparable electrical power consumption level, the super-dense array plasma actuator array significantly outperformed the grid-type configuration, reducing the total airfoil friction drag by approximately 22% at a free-stream velocity of 20 m/s. The magnitude of drag reduction was proportional to the dimensionless jet velocity ratio (r), and a threshold r = 0.014 existed under which little impact on airfoil drag could be discerned.

The Role of Carbon Fiber Composite Materials in Making Electric Aircraft a Reality

As the aerospace industry seeks sustainable alternatives to traditional aviation, electric aircraft have emerged as a promising solution to reduce carbon emissions and reliance on fossil fuels. Central to this transition is the development and integration of advanced materials that enhance the performance and efficiency of these next-generation aircraft. Compound materials possess various significant abilities, including the capability to withstand fatigue, resist corrosion, and manufacture lightweight components with minimal compromise to reliability, among others. Nanocomposites constitute a subset of materials within compounds, recognized for their superior mechanical properties compared to standard composite materials. The utilization of nanocomposites in the aerospace sector is presently encountering a research gap, primarily in identifying future application scopes. This paper reviews the critical role of carbon fiber composites and nanocomposites in electric aviation, highlighting their transformative impact on aircraft design, battery integration, and overall sustainability. By offering unparalleled strength-to-weight ratios, superior thermal management, and innovative structural possibilities, these materials significantly advance the capabilities of electric aircraft. Furthermore, it discusses the advancements in material technology, including high-temperature composites, hybrid composites, and nanocomposite materials, and addresses the challenges and future directions in composite application. The paper underscores the pivotal role of composite materials in achieving a greener, more efficient, and technologically advanced aerospace industry, marking a significant step towards sustainable air transportation.

Advancing Electric Flight through Innovative Materials in Aerospace Propulsion Systems

The advent of electric aircraft heralds a transformative era in aviation, offering a sustainable alternative to conventional aircraft that significantly contribute to carbon emissions. This paper discusses the application of advanced materials in overcoming the technical hurdles associated with electric propulsion systems, focusing on their application in airframe construction, electrical conductors, thermal management, and battery technology to enhance the performance and sustainability of electric aircraft. Advanced composites like carbon fiber reinforced polymer (CFRP) are explored for their potential to reduce aircraft weight and improve mechanical properties. The paper also addresses the challenges of thermal management in electric propulsion systems, highlighting the use of phase change materials (PCMs) and advanced ceramics for efficient heat dissipation. Furthermore, the exploration of high-energy-density cathode materials, innovative anode materials, and solid-state electrolytes is discussed in the context of developing lightweight, high-capacity batteries for electric aircraft. Despite the promising advancements in material science and the potential benefits of electric aviation, the paper acknowledges the existing challenges, including the high cost of advanced materials, the need for improved energy storage solutions, and the environmental impact of material production.

Effect of Spray Rails on Takeoff Performance of Amphibian Aircraft

Effect of Spray Rails on Takeoff Performance of Amphibian Aircraft

Simplified Spatial Wind Vector Interpolation Method for Airport Runway Orientation Analysis

Runway orientation, guided by windrose analysis is crucial in airport planning as it directly influences aircraft performance and airport capacity. Proper alignment reduces crosswind components during takeoff and landing, ensuring safer operations and increase runway coverage. For a new airport in a location where comprehensive historical wind data is not available, prediction methods become an invaluable tool. To address this issue, this paper proposes a simplified interpolation method to predict wind data at target location based on available data from surrounding climate station readings. This paper validates the proposed method through a comparative analysis of predicted and actual windrose and its subsequent runway coverage at two prominent currently operational Indonesian airports: Soekarno Hatta International Airport in Cengkareng (CGK) and Sultan Hasanuddin International Airport in Ujung Pandang (UPG). Additionally, the study employs the proposed method to determine the optimal runway orientation for a new VVIP airport in Indonesia's new capital city (IKN), Nusantara. The analysis reveals that the proposed interpolation method yields runway heading recommendations closely aligned with those derived from actual wind data, both for the case of CGK and UPG airport. The proposed method recommends optimal runway heading between 03-21 and 08-26 for new VVIP Airport at Nusantara, new capital city of Indonesia (IKN).

Real-time optimization of wing drag and lift performance using a movable leading edge

A real-time optimization strategy can provide any system with a considerable boost in performance on the fly, which in real-world applications can be translated to lower energy consumption or higher efficiency. This study investigates the particular case of using real-time optimization to improve wing aerodynamic performance with a dynamically activated deflectable leading edge. Its activation aims to minimize drag and maximize lift and is governed by real-time and gradient-based optimization. An extension to a classic method is suggested to enhance gradient estimation accuracy. Experimental data are obtained at a Reynolds number of 2.0×105 with the wing fixed at five positions. For each of these positions, optimal leading-edge deflections are found. The results indicate that deflecting the leading edge has a negligible impact on drag and lift before the stall onset. However, the reduction in the pitching moment cannot be ignored. When the wing is experiencing a proper stall, the movable leading edge yields remarkable enhancements, with the lift being approximately raised by 45% together with a substantial increase in the critical angle of attack. The findings highlight the potential of real-time optimization in experimental aerodynamic studies, reinvigorating its application in improving aircraft performance.

Finite Element Analysis of the Main Structure for a New Conceptual Aircraft Passenger Vertical Seat Design

Standing cabin is a new design concept of aircraft passenger cabin whereby passengers are transported in the standing position throughout flight as opposed to current seated position. An important element of this cabin concept is the design of the vertical seat to support the passengers, which has to be in compliance with requirements of aviation regulation. In commercial aircraft applications, weight of passenger seat is a significant factor that can affect flight performance of the aircraft. Meanwhile, the seat’s structure should have adequate strength to ensure proper safety provision to passengers. Hence weight and strength are potentially two conflicting design requirements for the vertical seat, and the optimum structural design should have the best compromise with regards to these two requirements. In this study, parametric study on primary structural design of the proposed vertical seat concept is done to obtain an optimized design that satisfies the strength requirements for safety of passengers without causing high penalty to the overall aircraft weight and performance. The simulation analysis for the main structures of the vertical seat design is conducted through finite element method using ABAQUS software. From the results of the analysis, main structural parts made from aluminium alloy with diameter 90 mm and thickness 3 mm are selected for the optimum vertical seat design. This standing seat design has also been shown to have adequate strength and can satisfy the safety regulation requirement without failure. The maximum stress on the seat’s structure under 9-g forward loading is found to be 147.5 MPa, which is lower than ultimate strength of aluminium. Moreover, the seat’s weight is estimated to be 9.5 kg and the maximum deflection of its main structures under forward 9-g loading is 28.42 mm. All in all, the stress analysis results highlight that the structural strength of the optimal vertical seat design can satisfy the requirements of the governing aviation regulations to provide safety to passengers.

An aviation accident report data-driven approach to scenario design for a centrifuge-based dynamic flight simulator

The use of flight simulators in investigating an aviation incident or accident related to human errors has been identified as an important part of a strategy to improve safety. This study aimed to replicate a real flight of the MiG-29 aircraft using a centrifuge-based dynamic flight simulator and to determine the simulator’s accuracy in recreating in-flight aircraft performance. A 60-second recording of the real flight of the MiG-29 aircraft, captured by the flight data recorder, was chosen for replication in the HTC-07 human training centrifuge simulator. To evaluate how accurately the simulator replicates the performance of the aircraft, the linear accelerations and angular velocities acting on a pilot during the real flight were compared with those during the replication of that flight in the simulator. The fit of these parameters was assessed using the root mean square percentage error (RMSPE) and the correlation coefficient (r). The highest replication accuracy was achieved for the vertical component of the linear acceleration (RMSPE=2068; r=0.98), while the worst result was obtained for the longitudinal component (RMSPE=14205; r=0.31). Inaccuracies were much more pronounced for the angular velocity. The roll angular velocity had the lowest replication error (RMSPE=12640). However, its correlation with the recorded velocity during the real flight was very weak (r=-0.02). Despite some inaccuracies in replicating other components of the acceleration and angular velocity vectors, the HTC-07 simulator seems valuable for investigating aviation incidents or accidents related to human factors.

An Unsteady Reynolds–Averaged Navier–Stokes–Large Eddy Simulation Study of Propeller–Airframe Interaction in Distributed Electric Propulsion

A conceptual framework is presented to determine the improvement in the aerodynamic performance of a canard aircraft fitted with distributed propellers along its main wing. A preliminary study is described with four airframe–propeller configurations predominantly studied in academic and commercial designs. The leading edge–based tractors and trailing edge–based pushers are identified as configurations of interest for the main study. Subsequently, a Navier–Stokes solver is used to simulate the flow using two numerical approaches–a modified steady-state actuator disk and an unsteady rotating propeller profile. Moving meshes with rotating sub-domains are used with a hybrid RANS-LES-based turbulence model while the actuator disks are modified to include viscous swirl effects. The preliminary study shows a local minimum in the change in CL and CD at 10∘ for the pusher and tractor configurations. The main study then demonstrates the outperformance of the pushers over tractors quantified using CL and CL/CD. There is a clear preference for the pushers as they increase the lifting capacity of the aircraft without disproportionately increasing the drag due to the flow smoothening by the suction of the pusher propellers over the main wing. The pushers also delay the separation of the boundary layer whereas the tractors are unable to prevent the formation of the separation bubble despite injecting momentum through their slipstreams into the flow. The results from the two numerical approaches are then compared for accuracy in designing DEP configurations for an airframe.

Superhydrophobic Coatings for Corrosion Protection of Stainless Steel

Corrosion is a persistent challenge in the aviation industry, affecting the safety, performance, and maintenance costs of aircraft. While composite materials have gained widespread use due to their lightweight properties and corrosion resistance, certain critical parts, such as the wing and empennage leading edges and the engine inlet, demand alternative solutions. Aluminum, titanium, and stainless steel emerge as mandatory materials for such components, given their exceptional strength and durability. However, protecting these metallic components from corrosion remains crucial. In this paper, we present a study aimed at evaluating the corrosion resistance of stainless steel, employed as an erosion shielding panel for a composite vehicle’s wing, layered with a superhydrophobic coating. The samples with and without coating have been characterized by contact angle measurements, microscopy (optical and electronic), and visual inspection after immersion in two solutions, NaCl and NaOH, respectively. The application of the superhydrophobic coating demonstrated a significant reduction in corrosion extent, especially in the demanding NaCl environment. This was evidenced by diminished formation of ripples and surface roughness, decreased iron oxide formation from oxidative processes, and a lower Surface Free Energy value in both liquid environments. Notably, the surface maintained its superhydrophobic properties even following an 8-day immersion in NaCl and NaOH solutions, demonstrating the reliability of the superhydrophobic coating offering as a potential solution to enhance the longevity and reliability of aircraft structures.