Hybrid Aircraft Research Articles

Электрические и гибридные самолеты: перспективы создания

The historical stages and modern achievements in the field of increasingly growing use of electricity in aircrafts both in Russia and abroad are analyzed. The analysis results are used as a basis for presenting the key technologies using which the concept of constructing a fully electrical aircraft can be embodied. The analysis results also open the possibility to consider the specific challenges that will be faced in this problem area. An analysis of the historical stages through which attempts to fit aircrafts with electrical devices have already passed shows that, despite the tendency toward more and more extensive use of on-board electrical devices for all classes of aircrafts, the level of electrification in them still does not exceed 25%. A cardinal increase in the electrification level is only possible by equipping aircrafts with electric traction motors, which, however, will entail a number of technical and technological problems. A comprehensive approach to designing the power systems of electrical and hybrid aircrafts is proposed, the use of which will make it possible to estimate the extent to which the requirements that have been put forth can be fulfilled and to perform a comparative analysis of design solutions. It is shown that the problem of making an aircraft more energy-efficient and more energy-intensive should be solved jointly with ensuring its safety with making the maximal use of methods for estimating and predicting its condition. Efforts aimed at finding ways to integrate the on-board equipment, airframe, and propulsion system for working out the most efficient versions of electrical and hybrid aircrafts should be taken. The problems that have been set forth cannot be solved without widely using computer and information technologies.

The Future of Conventional Aircraft Ground Propulsion Systems in Relation to Fuel Consumption and CO2 Emission

Aircraft spends a minimum of 20 minutes using its main engine to taxi from the airport terminal gate to the runway, where the aircraft takes-off and similarly to the terminal gate after landing. During taxi operation, aircraft burns a lot of fuel, generates large quantity of emissions and the engine in the process of taxiing is exposed to damage due to Foreign Object Damage (FOD). This results in huge operational and maintenance cost as well as carbon emission tax which are all at the expense of the airline. EGTS is a recent technology designed to prevent aircraft from using its main engine for taxi operation and this in turn reduces the rate of fuel consumption, slashes carbon emissions and minimises operational and maintenance cost. This paper examines the viability of using EGTS in single engines for taxi operation rather than the aircraft engine. Block fuel savings was calculated for two engine, single engine and hybrid aircraft and it was observed that two engine aircraft using EGTS saved 110kg block fuel, single engine saved 74kg and for hybrid engine the block fuel savings was 50kg. Block fuel savings was calculated for aircraft such as airbus A320, airbus A380, Cessna 172 and A600ST and it was observed that EGTS is more compatible with airbus A320 but was not recommended for A600ST and A380 due to extra weight implication and for Cessna 172, EGTS was not necessary because the aircraft weight is low and consumes less fuel already. It was observed that the higher the aircraft weight including the extra weight of EGTS, the higher the fuel consumption emission as well as the torque required to overcome drag force when the aircraft operates in air. CO2 emission was also calculated for aircraft with EGTS and aircraft without installation, the result for aircraft with EGTS showed 797.56kg reduction of CO2 emission when compared to aircraft without EGTS. Comparably, EGTS was proven to be viable in terms of fuel savings, CO2 emissions, operational and maintenance cost than its contemporary Ground Propulsion Systems (GPS) for single aircraft engines and therefore, was recommended for aircraft in airbus A320 category to help minimise global warming which results from CO2 emission during taxing operations.

Modeling of parasitic effects in multi-rotor hybrid aircrafts (Part-II)

Modeling of parasitic effects in multi-rotor hybrid aircrafts (Part-II)

Modeling of parasitic effects in multi‐rotor hybrid aircrafts: Part‐I

Modeling of parasitic effects in multi‐rotor hybrid aircrafts: Part‐I

Adaptive Air-to-Ground Secure Communication System Based on ADS-B and Wide-Area Multilateration

A novel air-to-ground (ATG) communication system, which is based on adaptive modulation and beamforming enabled by automatic dependent surveillance-broadcast (ADS-B) and multilateration techniques, is presented in this paper. From an aircraft geolocation perspective, the proposed multilateration technique uses the time-difference-of-arrival (TDOA), angle-of-arrival (AOA), and frequency-difference-of-arrival (FDOA) features within the ADS-B signal to implement the hybrid geolocation mechanism. Moreover, this hybrid mechanism aims for the optimal selection of multilateration sensors to provide a precise aircraft geolocation estimate by minimizing the geometric dilution-of-precision (GDOP) metric and imparts significant resilience to the current ADS-B-based geolocation framework to withstand any form of attack involving aircraft impersonation and ADS-B message infringement. From an ATG communication perspective, the ground base stations can use this hybrid aircraft geolocation estimate to dynamically adapt their modulation parameters and transmission beampattern in an effort to provide a high-data-rate secure ATG communication link. Additionally, we develop a hardware prototype that is highly accurate in estimating AOA data and facilitating TDOA and FDOA extraction associated with the received ADS-B signal. This hardware setup for the ADS-B-based ATG system is analytically established and validated with commercially available universal software-defined radio peripheral units. This hardware setup displays 1.5° AOA estimation accuracy, whereas the simulated geolocation accuracy is approximately 30 m over 100 nautical miles for a typical aircraft trajectory. The adaptive modulation and beamforming approach assisted by the proposed GDOP-minimization-based multilateration strategy achieves significant enhancement in throughput and reduction in packet error rate.

Particular risk analysis: impact on hybrid aircraft design

Purpose – This document presents a Particular Risks Assessment (PRA) performed on an Uncontained Engine Rotor Failure (UERF) event for the new aircraft design hybrid Extremely Short Take Off and Landing All Surface (ESTOLAS) aircraft. All three propellers of the ESTOLAS (one hub propeller and two feed propellers) are evaluated for their impact on the aircraft in case of an UERF. The purpose of this paper is to present an illustration of the safety analysis and its requirement in new aircraft development. Design/methodology/approach – The methodology used is in accordance with the aerospace industry safety standard Society of Automobile Engineers (SAE) Aerospace Recommended Practices (ARP) 4,761 (Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment). Trajectory analyses are used on a digital mock-up of the aircraft to simulate the movement of the propeller blade fragments and its effect on the aircraft and its systems. Findings – The paper provides an insight into the industry practice of performing PRA on new aircraft designs. The study identifies safe and unsafe regions of the aircraft, with the UERF event in mind. Technical solutions are suggested to minimize the damage to the aircraft and its systems. Originality/value – This document fulfills the originality criterion, since it is an analysis performed on a new aircraft design – the ESTOLAS.

Stability and Takeoff Ground Roll Issues of Hybrid Buoyant Aircraft

In the field of aviation it is well known that a vehicle’s stability and takeoff flight segment are critical. This issue becomes more critical for a hybrid aircraft which is concealed as an airship with huge volume of hull as compared with fuselage of a conventional aircraft. In the present work, stability issues of a generic model of airship and of a conceptual model of hybrid aircraft are discussed. Special emphasis is given for future sizing of empennages of IWHA-14, a hybrid aircraft concept proposed for Malaysian inter island transportation. Effect of gondola position on rotation angle for takeoff ground roll was analyzed and it was found that such configurations can meet the requirement of minimum roll angle.

THE CALCULATION AERODYNAMIC CHARACTERISTICS OF A HYBRID AEROSTATIC AIRCRAFT

The article presents a justification layout a new type aircraft with two different sources lifting force – aerodynamic and aerostatic. Consider especially the exploitation aircraft easier to air, identified key issues research, unresolved tasks, formulated the task. Logged matching aerodynamic profile for bearing surface hybrid aircraft, made its adaptation. Using the method of computational aerodynamics the calculation of the flow around the bearing surface, presents an analysis of the results and conclusions and recommendations are given on an aerodynamic design.

Cost-based flight technique optimization for hybrid energy aircraft

Purpose – The aim of the paper is to establish the COst-Specific Air Range (COSAR) as a new figure-of-merit based on the cost of energy to optimise the flight profile of a hybrid energy aircraft. Design/methodology/approach – After reviewing the expression and the application of the specific air range (SAR) and of the energy-specific air range (ESAR), the need of a new figure-of-merit for flight technique optimisation of hybrid energy aircraft is motivated. Based on the specific cost of the energies consumed, the mathematical expression of COSAR is derived. To enable optimum economics operations, a cost index (CI) derivation is introduced for a variety of hybrid-electric concepts to consider the additional time-related cost. The application of COSAR and of the CI is demonstrated for cruise optimisation of a hybrid-electric retrofit aircraft concept. Findings – As a consequence of the consumption of multiple energy sources in a hybrid aircraft, optimisation according to the objective functions SAR and ESAR...

Integrated fuel-battery hybrid for a narrow-body sized transport aircraft

Purpose – The aim of this paper is to assess the potential of fuel-battery hybrid narrow-body (180PAX) transport aircraft according to different design ranges for an entry-into-service (EIS) of 2035. Design/methodology/approach – The philosophy used in the design of the twin-engine fuel-battery hybrid concept is to use the power of an electric motor during cruise to drive a single propulsive device, whereas the other one is powered conventionally by an advanced gas turbine. A methodology for the sizing and performance assessment of hybrid energy aircraft was previously proposed by the authors. Based on this methodology, the overall sizing effects at aircraft level are considered to size the hybrid aircraft to different range applications. To evaluate the hybrid concept, performance was contrasted against a conventional aircraft projected to EIS 2035 and sized for identical requirements. Additionally, sensitivity of the prospects against different battery technology states was analysed. Findings – The best suited aircraft market for the application of the fuel-battery hybrid transport aircraft concept considered is the regional segment. Under the assumption of a battery-specific energy of 1.5 kWh/kg, block fuel reduction up to 20 per cent could be achieved concurrently with a gate-to-gate neutral energy consumption compared to an advanced gas-turbine aircraft. However, a large increase in maximum take-off weight (MTOW) occurs resulting from battery weight, the additional electrical system weight, and the cascading sizing effects. It strongly counteracts the benefit of the hybrid-electric propulsion technology used in this concept for lower battery-specific energy and for longer design ranges. Practical implications – The findings will contribute to the evaluation of the feasibility and impact of hybrid energy transport aircraft as potential key enablers of the European and US aeronautical program goals towards 2035. Originality/value – The paper draws its value from the consideration of the overall sizing effects at aircraft level and in particular the impact of the hybrid-electric propulsion system to investigate the prospects of fuel-battery hybrid narrow-body transport aircraft sized at different design ranges.

Finite element modeling of mechanically fastened composite-aluminum joints in aircraft structures

A three-dimensional, solid finite element model of a composite-aluminum single-lap bolted joint with a countersunk titanium fastener is developed. The model includes progressive damage behavior of the composite and a plasticity model for the metals. The response to static loading is compared to experimental results from the literature. It is shown that the model predicts the initiation and the development of the damage well, up to failure load. The model is used to evaluate the local force–displacement responses of a number of single-lap joints installed in a hybrid composite-aluminum wing-like structure. A structural model is made where the fasteners are represented by two-node connector elements which are assigned the force–displacement characteristics determined by local models. The behavior of the wing box is simulated for bending and twisting loads applied together with an increased temperature and the distribution of fastener forces and the progressive fastener failure is studied. It is shown that the fastener forces caused by the temperature difference are of significant magnitude and should be taken into account in the design of hybrid aircraft structures. It is concluded that, the account of the non-linear response of the joints results in a less conservative load distribution at ultimate failure load.

Design and control for rotor-fixed wing hybrid aircraft

This article presents a model of rotor-fixed wing hybrid aircraft, which can operate as a helicopter as well as transition to fixed-wing flight. The control mission includes: hover, vertical take-off and landing, forward flight, from hover to forward flight, and vice versa. A backstepping-based control method for the aircraft is designed to keep the flying height invariant during mode transitions from hover to forward flight and vice versa. The other control missions mentioned are not considered in this article.

Modeling and Control of a Small-Scale Hybrid Aircraft

AbstractHybrid aircrafts are unique type of aircrafts that combine the hover capability of helicopters with the speed and range of airplanes. In this work, we propose a novel hybrid aircraft based on the fixed-wing airplane and quadrotor structures. A complete mathematical model of the aircraft, in helicopter, transition and airplane flight modes is presented. Furthermore, a nonlinear controller for stabilizing the aircraft at hover is proposed. Finally, simulation results are presented in order to illustrate performances of the proposed controller.