Aviation

Comparative efficiency testing of a composite hydraulic cylinder

2025-02-14T18:30:34+02:00

The paper points to the increasing use of composite materials in hydraulic components. This entails many benefits, such as weight reduction which is particularly important in aviation. However, new problems arise with the use of new materials. With regard to a hydraulic actuator whose cylinder is made of a composite material, one of the issues is ensuring adequate efficiency, comparable to that of a steel cylinder. The efficiency of a hydraulic actuator is related to friction processes in the structural nodes and to leaks in the cylinder. This paper presents the original results of volumetric, hydraulic-mechanical and total efficiency tests of three designs differing in the material used as a liner of a cylinder. The materials considered as liner were CFRP composite, polyurethane F180. In addition, a steel liner was considered as a reference. Variations in actuator efficiency depending on the liner used were indicated.

Parametric analysis of wing planforms to determine an optimal wing design

2025-02-17T18:30:36+02:00

In designing of Unmanned Aerial Vehicle (UAV), selection of an optimal wing design is a crucial part of complete UAV design process. This research explores the different aerodynamic parameters and the comparison of different wing planforms to ascertain the optimal wing design and improve the overall efficiency of an UAV. The computational analysis using XFLR5 and Open-VSP software is studied to investigate the various aerodynamic parameters of wing. The impact of aspect ratio, taper ratio, wing reference area, coefficient of lift and drag, and stall angle of attack are examined using the Analytical Hierarchy Process (AHP). The results emphasize the importance of different wing planforms and create easier selection of planform for the UAV designers. The study does not only provide the values for operating parameters but also offers practical guidance for design optimization. The semi tapered, and moderate tapered (λ = 0.5) wings are the good choice to select at the initial phase of design. The highly tapered and elliptical wings provide higher lift but are not efficient in the stalling conditions. Furthermore, the rectangular wing provides elliptical lift distribution, but it is inefficient in the lift generation.

Artificial intelligence as applied to classifying epoxy composites for aircraft

2025-02-27T18:30:46+02:00

The problem of classification of epoxy composites used for the manufacture of aircraft structures is solved by machine learning methods: neural network, reinforced trees and random forests. Classification metrics were obtained for each method used. Parameters such as precision, recall, F1 score and support were determined. The neural network classifier demonstrated the highest results. Boosted trees and random forests showed slightly lower results than the neural network method. At the same time, the classification metrics were high enough in each case. Therefore, machine learning methods effectively classify epoxy composites. The results obtained are in good agreement with the experimental ones. The prediction accuracy score obtained using each method was greater than 0.88.

Component definition innovation plan as a tool to allow flight simulator training device roadmapping

2025-03-05T18:30:53+02:00

The use of flight simulators as a complement to pilot training offers significant advantages in reducing costs and risks associated with aircraft accidents, in addition to increasing safety and situational awareness during the practical phases of flight. However, the development of equipment to support pilot training has been carried out with an exclusive focus on this application, overlooking the exploration of alternative uses or new business opportunities that could diversify revenue streams and foster innovation. In this study, a method was developed to identify components that support the Technology Roadmapping process. The application phases are described, and each step is illustrated with a case study on developing a flight simulator training device. The results present potential markets, products, technologies, resources, and partners, forming a framework for innovation planning in aeronautical flight training. Specifically, the potential for implementing affordable full-motion flight simulators is examined, including applications in amusement parks for leisure, incentive flights for new crew, providing a passenger flight experience in the context of advanced air mobility, and, primarily, referencing flight centers to enhance airmanship skills and flight safety.

Developing Alsim AL250 based eVTOL flight simulator

2025-03-13T18:31:01+02:00

A novel eVTOL aircraft simulator was developed for research and teaching purposes. The simulator integrated MATLAB/Simulink flight dynamics model with Alsim AL250 FNPT II flight simulator. Simplified version of the Neoptera’s eOpter eVTOL aircraft was used as a test case to verify the flight simulator. It was shown that the aircraft responded as expected by the pilot and that the traditional handling qualities metrics and VTOL requirements (MIL-F-83300, MIL-F-8785C, EASA-SC-VTOL-02) could be used along the flight simulator to assess aircraft being tested. Take-off showed an increase in climb rate as well as overshoot of the target altitude with higher RPM setting. Qualitative assessment of transition showed suitable stability and control feel for the eVTOL to be operated by a single pilot. Quantitative assessment of the longitudinal manoeuvring characteristics showed Level 2 SPPO handling qualities for the tested eVTOL aircraft, qualitative definition of which agreed with the pilot’s opinion. It was also shown that increasing initial velocity for the SPPO mode test increased the mode’s natural frequency, but almost did not affect the damping ratio, which is within the expectations.

Human factors considerations for critical maintenance tasks and their effect on the transition to digital documentation: an exploratory expert survey

2025-03-20T18:31:07+02:00

Digitised maintenance documentation will soon be the norm in aviation. Failure to correctly perform maintenance tasks may lead to aviation safety hazardous events. This article explores the views of aviation maintenance subject matter experts on errors affecting critical maintenance tasks and how views can inform transition to digitised documentation. This exploratory study offers a fresh view on human factors’ implications around critical maintenance tasks and their relation to digital documentation. A cross-sectional design method was utilised. Anonymous responses were collected with a mixed-methods questionnaire from convenience sample of participants from different aircraft maintenance and continuing airworthiness management organisations. Expert opinions of 25 aircraft maintenance and technical services engineers were recorded. All participants had personal experience with maintenance errors, where human factors attributed to these errors. They highlighted the lack of human factors’ awareness and the need to strengthen their contributory role in critical maintenance tasks. Participants’ views appeared divided in terms of challenges associated with digital documentation utilisation. Positive features emerged, such as critical maintenance tasks or duplicate/independent inspections’ highlighting, notes and warnings’ higher visibility, up-to-date documentation availability and better connectivity among activities. Negative themes concentrated on the tactile nature of paper and on the additional technology knowledge requirements.

Disadvantageous effects of vibrations on the micro-hydraulic relief valve: experimental approach

2025-03-27T09:52:47+02:00

The paper discusses the negative impact of external mechanical vibrations, which lead to the malfunction of drive systems, particularly affecting hydrostatic drives. The hydraulic system components feature a spring-supported control element that vibrates due to external mechanical vibrations, leading to pressure pulsation. The resulting pressure pulsation causes many unfavorable characteristics of hydraulic system operation. The positive displacement pump is shown as the main source of pressure pulsation in a hydraulic system. For selected frequencies of external mechanical vibration close to the natural frequency of the valve control element, the resulting pressure pulsation far exceeds the pressure pulsation resulting from the displacement pump. This paper presents selected results showing pressure pulsations as a consequence of the displacement pump and external mechanical vibrations acting on the pressure-relief valve.