Improving the efficiency of drone propulsion is crucial in extending flight times and cutting down on energy losses during dynamic maneuvers. Traditional Brushless DC (BLDC) motor controllers depend on mathematical models and reactive adjustments, which often struggle to keep up with sudden changes in load, wind disturbances, and fluctuations in battery voltage. To tackle these challenges, this study presents an innovative control strategy that merges Model-Free Adaptive Control (MFAC) with a bio-inspired hybrid optimization technique inspired by Eel Foraging and Gooseneck Barnacle behaviors. Unlike model-based methods, MFAC continuously fine-tunes its control actions using real-time sensor data, eliminating the need for motor parameters and making it robust against unpredictable operating conditions. The hybrid optimization algorithm enhances this adaptability by swiftly identifying the most energy-efficient control inputs that ensure necessary thrust while minimizing switching losses, torque ripple, and power consumption. Experimental tests with a 1000 KV BLDC motor show significant improvements in torque–speed stability, rapid convergence in controller tuning, and a marked reduction in power demand during critical drone flight modes like hovering and ascending. These findings suggest that combining MFAC with bio-inspired optimization paves the way for developing high-efficiency UAV propulsion systems that can achieve longer endurance, reliable real-time control, and less reliance on complex motor models.

Hail impact poses a critical threat to the structural integrity of aircraft composite skins, with its severity influenced by changing climatic conditions and increasing aircraft operating speeds. In this study, a combined experimental and numerical investigation is undertaken to examine the impact response of Carbon Fibre-Reinforced Polymer (CFRP) laminates subjected to hail-ice impact, with the objective of improving the understanding of damage behaviour in aerospace composite structures. Symmetric CFRP laminates of approximately 3 mm in thickness, representative of typical aircraft skin configurations, are considered for the investigation. Controlled hail-ice impact tests are conducted at a specified impact velocity to simulate realistic hail strike conditions, and repeated impact events are considered to evaluate the influence of cumulative damage.

Post-impact damage assessment is carried out using ultrasonic C-scan inspection and optical microscopy to identify internal damage modes such as delamination, matrix cracking, and fibre failure. In parallel, numerical simulations are performed using the explicit finite element solver LS-DYNA to replicate the experimental impact conditions. The numerical model enables the evaluation of deformation behaviour, stress distribution, and energy transfer during the impact event, thereby providing insight into the progressive damage mechanisms of the CFRP laminate. The combined experimental and numerical framework presented in this work aims to support the development of improved composite layup designs and validated predictive methodologies for assessing hail impact tolerance in future aircraft applications.

Unmanned Aerial Vehicles (UAVs) with Vertical Take-Off and Landing (VTOL) capability have gained significant importance due to their operational flexibility, compact deployment, and suitability for diverse applications. However, experimental validation of VTOL UAV performance through flight testing is often associated with high cost, safety risks, and limited repeatability. To address these challenges, this work presents the design and fabrication of a ground-based test bed for systematic performance evaluation of VTOL UAVs under controlled conditions.

The proposed test bed comprises a rigid modular aluminum frame integrated with a universal joint mechanism that permits controlled roll and pitch motion while constraining translational movement. The system is equipped with load cells for thrust and force measurement, a Bosch BNO055 nine-degree-of-freedom inertial measurement unit (IMU) for real-time attitude estimation, accelerometers for vibration analysis, and an anemometer to monitor airflow characteristics. Data acquisition and visualization are implemented using MATLAB and Python-based simulations developed in Visual Studio Code, enabling real-time monitoring of Euler angles, accelerations, and orientation dynamics.

Static structural analysis of the universal joint confirms that stress and deformation levels remain within permissible limits, ensuring structural safety and reliability. The experimental results demonstrate that the developed test bed effectively replicates key dynamic behaviors of VTOL UAVs without the risks associated with free-flight testing. The proposed system provides a low-cost, repeatable, and safe platform for UAV performance evaluation, control algorithm validation, and aeronautical engineering education.

Aircraft landing gear doors serve as lightweight auxiliary structures and are exposed to bending loads, localized compressive stresses, and occasional accidental impacts during their service life. Sandwich composite structures consisting of carbon-fiber reinforced polymer (CFRP) face sheets and a honeycomb core have become a preferred solution for such applications due to their high weight efficiency, corrosion resistance, and adaptable design characteristics. However, these structures may still develop internal damage mechanisms—such as delamination, honeycomb cell collapse, and skin–core debonding—that often remain undetected and create challenges for certification and durability evaluation.

In this study, a CFRP–honeycomb sandwich panel designed for landing gear door applications was fabricated and experimentally investigated. Mechanical characterization involved low-velocity drop-weight impact testing, three-point bending, and flatwise compression to represent realistic operational loading conditions. Microstructural examination using Scanning Electron Microscopy (SEM) was carried out to analyze damage progression, including matrix cracking, fiber fracture, adhesive degradation, and honeycomb cell wall deformation.

The results show that impact loading mainly produces subsurface delamination and surface indentation, flexural loading promotes core shear failure and face-sheet instability, and compressive loading leads to progressive collapse and densification of the honeycomb core. Overall, the experimental findings provide insight into failure evolution and mechanical response, supporting improved design considerations, inspection strategies, and damage-tolerance assessment for aerospace-grade sandwich composite structures.

The aerodynamic efficiency of small unmanned aerial vehicle (UAV) propellers is affected by losses arising from tip-vortex formation. At the blade tip, pressure differences between the suction and pressure surfaces induce vortical structures that increase induced losses, reduce effective thrust generation, and degrade propulsive performance. Mitigating these tip-related losses is critical for improving the efficiency of small-scale propellers operating at low Reynolds numbers.
This work presents an investigation into the effectiveness of blade-tip winglets as a passive flow-control technique to reduce thrust losses in a seven-inch propeller. Three distinct winglet configurations were examined: a canted winglet, an up/down wingtip fence, and a wingtip fence. All winglet geometries were designed using the NACA 4412 airfoil profile to ensure geometric consistency and aerodynamic characteristics. The baseline propeller and the winglet-integrated variants were modelled using CATIA V5 and fabricated from ABS material via fused deposition modelling.
Experimental evaluation was conducted using a custom-designed thrust measurement rig. Thrust data were acquired over a speed range of 4000 to 6000 rpm under repeatable conditions. Each winglet configuration was tested independently and compared against the baseline propeller to quantify performance improvements.
The results demonstrate that the incorporation of winglets leads to a measurable increase in thrust across the entire operating range. The canted winglet configuration yielded the most significant improvement, with thrust increases of 71% at 4000 rpm, 24.6% at 5000 rpm, and 32.8% at 6000 rpm, indicating superior suppression of spanwise flow and tip-vortex strength. The wingtip fence showed moderate thrust increases of 42%, 16.6%, and 10.7%, while the downward wingtip fence exhibited smaller but consistent increases of 13%, 8.7%, and 5%. Overall, the study establishes winglet integration as a simple, low-cost, and effective method for improving the aerodynamic performance of small UAV propellers.

Axial compressors are critical components of gas turbine engines and play a major role in determining overall engine efficiency and combustion performance. Enhancing turbulence at the compressor outlet can significantly improve air–fuel mixing in the combustion chamber. This study investigates a biomimetic surface modification inspired by the natural structure of palm tree leaves applied to the stator blade of the final stage of an axial compressor. The GE-J85 jet engine is selected as the reference configuration and the stator blade profile is based on the NACA 65410 aerofoil.

A palm leaf-inspired riblet pattern is introduced on the stator blade's surface to induce controlled flow disturbances. The pattern is designed with a 45° inclination and a riblet length of 1 mm distributed across the blade surface. The three-dimensional blade geometry is developed using CATIA V5 R20, and numerical analysis is performed using ANSYS under subsonic flow conditions. The aerodynamic and turbulence characteristics of the biomimetic stator blade are compared with those of a conventional smooth stator blade.

The computational results demonstrate a significant enhancement in turbulence parameters for the biomimetic configuration. The turbulent kinetic energy of the modified stator blade increases by approximately 29.5% compared to the baseline design. This increase is indicative of improved flow-mixing capability at the compressor exit. The findings suggest that biomimetic palm leaf surface patterns can be effectively applied to axial compressor stator blades to enhance turbulence and potentially improve combustion efficiency in gas turbine engines. This study highlights the potential of nature-inspired design approaches for advanced aerospace propulsion systems.

Boundary Layer Ingestion (BLI) is a promising approach for improving propulsive efficiency in electrified aircraft by recovering wake momentum deficit and reducing propulsive power. In conventional aircraft, engines ingest freestream air while the low-momentum wake is unutilized, resulting in kinetic energy loss. The aft-BLI propulsor enables partial recovery of this lost energy. Despite renewed interest in BLI, many numerical studies remain limited to cruise-only evaluations or isolated propulsor modeling, without examining broader flight-envelope performance.

In this work, a numerical framework is developed to study electrified aft-section BLI on an A320 aircraft configuration across multiple operating conditions. Three configurations are considered: a baseline aircraft, a cruciform-tail configuration introduced to reduce tail–wake interaction, and an aft-mounted BLI-integrated configuration. Steady, compressible CFD simulations are performed in ANSYS Fluent using geometries generated in OpenVSP. An unstructured mesh with body-of-influence refinement and inflation layers is used. Cruise conditions are defined at an altitude of 11 km under ISA assumptions, with turbulence modeled using the k–ω SST formulation and electrified propulsion represented using an actuator disk approach.

Under cruise conditions, the baseline configuration yields a drag coefficient of C_d =0.04498 (53.28 kN drag, 591.6 kN lift) using a reference wing area of 123 m². The cruciform-tail configuration shows a small drag increase with negligible lift variation. Passive BLI installation increases drag to C_d =0.0471, corresponding to an aerodynamic penalty of ~4.8%. When the BLI propulsor is activated, a reduction in effective drag to C_d ≈0.044 is observed, corresponding to a 2% reduction relative to the baseline. Propulsive power requirements decrease from 16.34 MW to 14.35 MW, yielding a Power Saving Coefficient of ~11.6%.

A conservative assessment indicates a realistic propulsive power saving of ~7%. Overall, this work establishes a consistent numerical methodology and demonstrates the preliminary aerodynamic and propulsive potential of electrified aft-section BLI.

This paper outlines the design and performance analysis of a composite sandwich flap for high-temperature applications, which is intended for use in advanced aerospace platforms. The composite sandwich flap has been designed as a multi-layer sandwich composite, which is capable of providing the required performance against the combined effects of aerodynamic, high-temperature, and structural loading conditions, which are encountered at high-speed flight profiles. A novel thermo-adaptive composite sandwich flap has been proposed, which comprises an IM7/BMI outer skin, an IM7/PEKK inner skin, and a titanium carbide (TiC) honeycomb core material. The proposed composite sandwich flap has been validated by aero-thermal simulations at Mach 2.2 and has resulted in a specific stiffness of 56.4 MJ/kg, which enables a 12.5% mass reduction compared to conventional titanium-based materials while maintaining a factor of safety of 1.6. The composite flap has effectively eliminated chordwise bowing by reducing it to 0.85 mm, thereby preventing the occurrence of premature flow separation. This has resulted in the aircraft maintaining its lift distribution, thereby enhancing its performance by 4.8% in the form of an improved L/D ratio of 4.25, which is a measure of efficiency. The results indicate that the advanced composite flap has provided the required aeroelastic integrity for relaxed stability aircraft at supersonic flight speeds.

This research investigates the Design and CFD-based aero-structural optimization study of Bio
inspired morphing swept wing using NACA 20612 supercritical asymmetric cambered airfoil
for the Bombardier CRJ-900 morphing as a transformative approach to enhance aerodynamic
efficiency, structural performance, and flight adaptability in modern aviation. Traditional fixed-wing designs impose limitations on lift-to-drag ratio optimization, maneuverability, and mission-specific performance. To address these challenges, the study proposes a morphing wing system
that integrates compliant structures, smart materials, and distributed actuation, enabling
continuous real-time modification of key geometric parameters such as camber, twist, and span.
The system allows the wing to dynamically adapt to varying flight regimes, including takeoff,
cruise, and maneuvering conditions, thereby achieving improved aerodynamic efficiency and
reduced structural loads. Comprehensive computational fluid dynamics (CFDs) simulations and
finite element analysis (FEA) were conducted to evaluate the aerodynamic and structural
behavior of the morphing wing across multiple configurations. Results indicate a significant
reduction in drag and optimized lift distribution, leading to enhanced fuel efficiency and
extended operational range. Additionally, structural analyses confirm that the adaptive wing
maintains sufficient stiffness and load-bearing capacity while accommodating shape
transformations, minimizing the risk of aeroelastic instabilities. The research further explores
actuation strategies using lightweight smart materials, including shape memory alloys and
piezoelectric composites, coupled with distributed sensors to enable real-time feedback control
for precise shape reconfiguration. Integration of these technologies demonstrates the feasibility
of mission-adaptive wings capable of responding autonomously to environmental variations,
turbulence, and changing aerodynamic demands. By merging aerodynamic optimization with
structural resilience, the proposed morphing wing concept presents a sustainable solution for
next-generation aviation, reducing carbon emissions and operational costs while increasing
overall aircraft performance. The findings support future developments in lightweight, efficient,
and environmentally responsible aircraft architectures that can adapt dynamically to diverse
mission profiles.

This study presents a numerical investigation of the aerodynamic effects of flap deflection, which varies along the span of the wing, with particular emphasis on lift distribution and wake formation of the flow. The objective of this study is to understand non-uniform flap deflection, which can be used as a passive flow control strategy in order to improve the efficiency of the wing. Two spanwise flap deflection profiles are considered, linear and cosine, in which deflection is maximum at the wing root and decreases towards the wing tip following the respective functional distribution. These include incompressible and compressible flow regimes to measure the overall impact of flap scheduling and compressibility on overall aerodynamic performance. Aside from analyzing global aerodynamic forces (lift and drag), the study also estimates pressure recovery and pressure uniformity to better characterize flow quality and the mixing of the flow downstream. The flow physics are analyzed from the surface- and field-based visualizations with flow path characteristics such as static pressure, Mach number, Q-criterion and streamlines, which provide the ability to clearly see separation directions, vortex cores and wake thickening features. The key findings of the study provide deep insights about pressure distribution and circulation, which significantly influences aerodynamic performance of the wing. These insights will help in designing a flexible wing with variable flap deflection. Such configurations have strong potential applications in the field of UAVs and commercial aircraft.