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This study seeks the effect on static thrust, thrust specific energy consumption (TSEC) and exhaust emissions of euro diesel-hydrogen dual-fuel combustion in a small turbojet engine.

Experimental studies are performed in a JetCat P80-SE type small turbojet engine. Euro diesel and hydrogen is fed through two different inlets in a common rail distributing fuel to the nozzles. Euro diesel fuel is fed by a liquid fuel pump to the engine, while hydrogen is fed by a fuel-line with a pressure of 5 bars from a gas cylinder with a pressure of approximately 200 bars.

At different engine speeds, it is found that there is a decrease at the TSEC between a range of 1% and 4.8% by different hydrogen energy fractions (HEF).

The amount of hydrogen is adjusted corresponding to a range of 0–20% of the total heat energy of the euro diesel and hydrogen fuels. The small turbojet engine is operated between a range of 35,000 and 95,000 rpm engine speeds.

On the other hand, remarkable improvements in exhaust emissions (i.e. CO, CO₂, HC and NO_x) are observed with HEFs.

This is through providing improvements in performance and exhaust emissions using hydrogen as an alternative to conventional jet fuel in gas turbine engines.

THE task of any recoil engine consists in transforming the chemical energy of fuel into the kinetic energy of gases leaving the nozzle. This article gives a brief survey of problems connected with transformations which the energy undergoes on the way from the fuel containers to the end of the nozzle. I have simplified as far as possible the problem, examining only the conditions in a rocket engine, without a gas turbine. Even in these simplified schemes the phenomena inside the combustion chamber and the nozzle are rather complicated and require careful examination.

A reliable and safe operation of fuel cells (FCs) is imperative for their application in aviation, especially within the main powertrain. Moreover, performance and lifetime requirements for technical and economic viability are demanding compared to their stationary or road transportation counterparts, while the operating conditions are considered challenging. Prognostics and health management (PHM) could represent a powerful tool for enhancing reliability, durability and performance by detecting, predicting and/or mitigating relevant degradation and failure mechanisms. Against this backdrop, the authors consider it of high relevance to obtain an understanding of the effectiveness of PHM approaches for polymer electrolyte fuel cells (PEFCs) for future aircraft applications, which represents the aim of this paper.

In this study, the authors first discuss application relevant failure modes, review state-of-the-art PHM approaches and, consecutively, assess the potential of FC control strategies for aviation. Aiming for a tangible, comparable metric for this initial assessment, the authors apply a published remaining useful life prediction method to load profiles for a range of aviation-specific applications.

The authors’ analysis shows significant potentials for lifetime improvement by (partial) avoidance of high power operation and rapid load change through control strategies. Tapping into these theoretical potentials, however, requires significant developments in the field of PEFC PHM and a focus on aviation specific degradation and performance testing.

The novelty of this study lies in creating an understanding of the potential of avoiding or preventing certain degradation modes by means of PHM in the PEFC specifically in aviation applications.

Aviation is not only one of the key contributors to the economy and social structure of the world but it is also an industry whose environmental impacts are being closely monitored. Aircraft efficiency and technological advancements have significantly reduced aviation noise and emissions in recent decades. Nevertheless, as the need for passenger and freight transportation grows, the aviation sector is becoming a primary source of environmental issues and a significant driver of global warming. This chapter focusses on environmentally sustainable aviation with a net-zero emission target. It also highlights sustainable aviation policies and collaborative initiatives in the aviation industry to meet the 2050 net-zero emission goal. While the industry's efforts have increased opportunities recently, the industry has also had to face several challenges to achieve the net-zero aviation target.

The primary driver of future aviation has recently been sustainability. The rapid development of radically new, disruptive technologies and solutions should be regularly evaluated to maintain the desired trends in sustainable aviation. The purpose of this research can be listed as follows: (i) to propose a sustainable performance index and methodology (ii) to evaluate the new technologies and solutions, and (iii) apply them to evaluate the effect of technologies and solutions under development.

This paper introduces a total sustainable performance index for evaluating the sustainability; demonstrates its applicability to future development processes; recognizes the supporting new technologies and solutions by implementing their identification, evaluation and selection processes; and defines the major trends and drivers maintaining the sustainability of the future aviation.

This study has resulted in a proposed new “total sustainable performance index,” and methodology of identifying key drivers that allow defining the technology and solution-driven trends, and defines the major trends and listed technologies and solutions that may have a determining role in given trends.

There are dilemmas on taking into account the positive effects of aviation on the economy and society that may overwrite the costs and limited information about the foresight on new technologies and solutions.

It depends on access to required inputs.

Two-way effects of solid expectations of society on the possible greening of aviation can be listed as the social implication of this research.

The proposed “total sustainability performance index” totally evaluates sustainability, including a penalty, considering the policy (regulation) and interest of future generations.

The purpose of this paper is to present a novel hybrid engine concept for a multi-fuel blended wing body (MFBWB) aircraft and assess the performance of this engine concept.

The proposed hybrid engine concept has several novel features which include a contra-rotating fan for implementing boundary layer ingestion, dual combustion chambers using cryogenic fuel (liquefied natural gas [LNG] or liquid hydrogen [LH2]) and kerosene in the inter-turbine burner (in flameless combustion mode) and a cooling system for bleed air cooling utilizing the cryogenic fuel. A zero-dimensional thermodynamic model of the proposed hybrid engine is created using Gas Turbine Simulation Program to parametrically analyse the performance of various possible engine architectures. Furthermore, the chosen engine architecture is optimized at a cycle reference point using a developed in-house thermodynamic engine model coupled with genetic algorithm.

Using LH2 and kerosene, the hybrid engine can theoretically reduce CO₂ emissions by around 80 per cent. Using LNG and kerosene, the CO₂ emissions are reduced by more than 20 per cent as compared to the baseline engine.

The hybrid engine is being investigated in the AHEAD project co-sponsored by the European Commission. This unique aircraft and engine combination will enable aviation to use cryogenic fuels like LH2 or LNG, and will make aviation sustainable.

The MFBWB concept and the hybrid engine is a novel concept which has not yet been investigated before. The potential implications of this technology are far reaching and will shape the future development in aviation.

TO say that the Twenty‐fourth S.B.A.C. Show was an unqualified success is perhaps to gild the lily. True there were disappointments— the delay which kept the TSR‐2 on the ground until well after the Show being one—but on the whole the British industry was well pleased with Farnborough week and if future sales could be related to the number of visitors then the order books would be full for many years to come. The total attendance at the Show was well over 400,000—this figure including just under 300,000 members of the public who paid to enter on the last three days of the Show. Those who argued in favour of allowing a two‐year interval between the 1962 Show and this one seem to be fully vindicated, for these attendance figures are an all‐time record. This augurs well for the future for it would appear that potential customers from overseas are still anxious to attend the Farnborough Show, while the public attendance figures indicate that Britain is still air‐minded to a very healthy degree. It is difficult to pick out any one feature or even one aircraft as being really outstanding at Farnborough, but certainly the range of rear‐engined civil jets (HS. 125, BAC One‐Eleven, Trident and VCIQ) served as a re‐minder that British aeronautical engineering prowess is without parallel, while the number of rotorcraft to be seen in the flying display empha‐sized the growing importance of the helicopter in both civil and military operations. As far as the value of Farnborough is concerned, it is certainly a most useful shop window for British aerospace products, and if few new orders are actually received at Farnborough, a very large number are announced— as our ’Orders and Contracts' column on page 332 bears witness. It is not possible to cover every exhibit displayed at the Farnborough Show but the following report describes a wide cross‐section beginning with the exhibits of the major airframe and engine companies.

With the predicted rise in air traffic, a growing need exists to make the aviation industry more environmentally sustainable in the long-term future. Research has shown that the turbo-electric distributed propulsion system (TeDP) could be the next disruptive technology that has the potential to meet the ambitious environmental goals set for the N + 3 time frame. This however will require the use of superconductivity, application of high-temperature superconducting materials and cryogenic liquids. This paper provides a brief overview of the technology and further discusses the benefits, advantages and new opportunities that may arise from the application of the technology.

This paper provides a brief overview of the technology and further discusses the benefits, advantages and new opportunities that may arise from the application of the technology.

Implementation of superconducting technology is currently one of the greater challenges faced and hence this article also reviews some of the key considerations to enable utilisation of cryogenic fuels in the future.

This paper provides a viewpoint and reviews some of the work undertaken in the field. It also provides a perspective on some new possibilities and advantages from using TeDP with cryogenic fuels.

The growth in air mobility, rising fuel prices and ambitious targets in emission reduction are some of the driving factors behind research towards more efficient aircraft. The purpose of this paper is to assess the application of a blended wing body (BWB) aircraft configuration with turbo-electric distributed propulsion in the military sector and to highlight the potential benefits that could be achieved for long-range and heavy payload applications.

Mission performance has been simulated using a point-mass approach and an engine performance code (TURBOMATCH) for the propulsion system. Payload-range charts were created to compare the performance of a BWB aircraft with various different fuels against the existing Boeing 777-200LR as a baseline.

When using kerosene, an increase in payload of 42 per cent was achieved but the use of liquefied natural gas enabled a 50 per cent payload increase over a design range of 7,500 NM. When liquid hydrogen (LH2) is used, the range may be limited to about 3,000 NM by the volume available for this low-density fuel, but the payload at this range could be increased by 137 per cent to 127,000 kg.

The results presented to estimate the extent to which the efficiency of military operations could be improved by making fewer trips to transport high-density and irregular cargo items and indicate how well the proposed alternatives would compare with present military aircraft. There are no existing NATO aircraft with such extended payload and range capacities. This paper, therefore, explores the potential of BWB aircraft with turbo-electric distributed propulsion as effective military transports.