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Article
Publication date: 28 September 2022

Ruihua Zhang and Weihua Liu

Determining the variation law of the oxygen concentration in the ullage space of the fuel tank is the key to the design of the inert system. Among various factors…

Abstract

Purpose

Determining the variation law of the oxygen concentration in the ullage space of the fuel tank is the key to the design of the inert system. Among various factors affecting the oxygen concentration in the ullage space of the fuel tank, the temperature difference between day and night shows particular importance while relevant analysis and calculation are scarce.

Design/methodology/approach

This study establishes a theoretical simulation model of the central wing fuel tank of an aircraft according to the relevant provisions of day-night temperature variation in FAR25 airworthiness regulations, verifies the model with the existing experimental data and discusses the corresponding relationship between the oxygen concentration in the ullage space of the fuel tank and the day-night temperature difference. The influence of day and night temperature difference, fuel type, fuel load rate, initial oxygen concentration, dissolved oxygen evolution and other factors on the oxygen concentration in the ullage space of the fuel tank were analyzed, and the limit of initial oxygen concentration of the fuel tank before the shutdown at night meeting the requirements of the airworthiness provisions was proposed.

Findings

The results show that the temperature difference between day and night, fuel load rate, initial oxygen concentration and other factors have different effects on the oxygen concentration in the ullage space of fuel tank. The initial oxygen concentration limit before shutdown shall be 2% below the 12% oxygen concentration stipulated by FAA.

Research limitations/implications

The research results in this paper will be of good reference value to the design of the inert system and the calculation of the flammability exposure evaluation time. This paper aims to be good reference of the design of the inert system and the calculation of the flammability exposure evaluation time.

Originality/value

The research results of this paper can provide practical guidance for the current civil airworthiness certification work.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 November 1987

Mayday

A means to alert the flightcrew of an aircraft's potentially unsafe low fuel quantity was the subject of a Notice of Proposed Rulemaking (NPRM) issued earlier this year…

Abstract

A means to alert the flightcrew of an aircraft's potentially unsafe low fuel quantity was the subject of a Notice of Proposed Rulemaking (NPRM) issued earlier this year. It was emphasised that there have been several recent fuel depletion incidents involving loss of power or thrust on all engines that could have resulted in forced landings and injury or loss of life. Most of these incidents resulted from improper fuel management techniques and this proposal from the FAA would require new transport category aircraft designs to incorporate a low fuel quantity alert to the flightcrew that would allow either correction of certain fuel management errors or the opportunity to make a safe landing prior to engine fuel starvation.

Details

Aircraft Engineering and Aerospace Technology, vol. 59 no. 11
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 29 September 2022

Peter Hooper

This paper aims to present experimental experience of heavy fuelling of a spark ignition crankcase scavenged two-stroke cycle unmanned aerial vehicle (UAV) engine…

Abstract

Purpose

This paper aims to present experimental experience of heavy fuelling of a spark ignition crankcase scavenged two-stroke cycle unmanned aerial vehicle (UAV) engine, particularly focusing on the effects of compression ratio variation, and to cross-correlate with the results of fluid dynamic modelling of the engine and fuels used.

Design/methodology/approach

One-dimensional modelling of the engine has been conducted using WAVE software supported by experimental dynamometer testing of a spark ignition UAV engine to construct a validated computational model using gasoline and kerosene JET A-1 fuels.

Findings

The investigation into the effects of compression ratio variation via fluid dynamic simulation and experimental testing has allowed an assessment of the approach for improving heavy fuel operation of UAV engines using auxiliary transfer port fuel injection. The power level achieved with reduced compression ratio heavy fuel operation is equal to 15.35 kW at 6,500 revolutions per minute compared to 16.27 kW from the standard gasoline engine or a reduction of 5.7%.

Practical implications

The studied engine is specifically designed for UAV applications. The validation of the computational models to explore the effects of compression ratio and heavy fuel injection on the solution and cost is supported by experimental tests.

Originality/value

The application of auxiliary port fuel injection of heavy fuel and associated compression ratio optimisation offers an alternative approach to achieve the safety and logistical challenges of the single fuel policy for UAVs. The application of WAVE to simulate crankcase scavenged two-stroke cycle engines has been applied in very few cases. This study shows further exploratory work in that context.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 23 September 2022

Hang-Wei Wan, Yu-Quan Wen and Qi Zhang

The reaction dynamics of combustible clouds at high temperatures and pressures are a common form of energy output in aerospace and explosion accidents. The cloud explosion…

Abstract

Purpose

The reaction dynamics of combustible clouds at high temperatures and pressures are a common form of energy output in aerospace and explosion accidents. The cloud explosion process is often affected by the external initial conditions. This study aims to numerically study the effects of airflow velocity, initial temperature and fuel concentration on the explosion behavior of isopropyl nitrate/air mixture in a semiconstrained combustor.

Design/methodology/approach

The discrete-phase model was adopted to consider the interaction between the gas-phase and droplet particles. A wave model was applied to the droplet breakup. A finite rate/eddy dissipation model was used to simulate the explosion process of the fuel cloud.

Findings

The peak pressure and temperature growth rate both decrease with the increasing initial temperature (1,000–2,200 K) of the combustor at a lower airflow velocity. The peak pressure increases with the increase of airflow velocity (50–100 m/s), whereas the peak temperature is not sensitive to the initial high temperature. The peak pressure of the two-phase explosion decreases with concentration (200–1,500 g/m3), whereas the peak temperature first increases and then decreases as the concentration increases.

Practical implications

Chain explosion reactions often occur under high-temperature, high-pressure and turbulent conditions. This study aims to provide prevention and data support for a gas–liquid two-phase explosion.

Originality/value

Sustained turbulence is realized by continuously injecting air and liquid fuel into a semiconfined high-temperature and high-pressure combustor to obtain the reaction dynamic parameters of a two-phase explosion.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 April 1967

J.D. Smith

The effects of a number of metals and alloys on the thermal stability of Avtur 50 have been evaluated from ASTM‐CRC and high temperature coker tests. The materials tested…

Abstract

The effects of a number of metals and alloys on the thermal stability of Avtur 50 have been evaluated from ASTM‐CRC and high temperature coker tests. The materials tested are used in current aircraft fuel systems or are possible alternatives for fuel systems of supersonic aircraft where they will be in contact with hot fuel. The alloys currently used in aircraft fuel systems have been classified and their probable effects on the stability of hot fuel listed. A number of the materials affected stability adversely, particularly alloys containing significant amounts of copper, and the use of these should be avoided. The pick‐up of copper by Avtur 50 at ambient temperature from alloys such as brass and gun‐metal has also been investigated. The results indicated that sufficient copper to affect thermal stability adversely is readily picked up from these alloys.

Details

Aircraft Engineering and Aerospace Technology, vol. 39 no. 4
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 May 2006

Changduk Kong, Myoung‐cheol Kang, Chang‐ho Lee and Dong‐ju Han

To set‐up a specific design procedure for the smart unmanned aerial vehicle (UAV) fuel supply system which has been developed by Korean Aerospace Research Institute, and…

1826

Abstract

Purpose

To set‐up a specific design procedure for the smart unmanned aerial vehicle (UAV) fuel supply system which has been developed by Korean Aerospace Research Institute, and to design it preliminarily with the fuel system requirement and target reliabilities.

Design/methodology/approach

The fuel system layout and fuel tank were determined through consideration of total fuel volume, fuel flow rate, reliability, weight, centre of gravity, etc. In sizing of components such as booster pumps, jet pumps, piping system, vent subsystem, refuelling and defuelling subsystem, engine fuel flow requirement, pressure loss, component failure rate, weight and centre of gravity were considered. Finally, the reliability analysis of the preliminary designed fuel system was carried out.

Findings

According to the reliability analysis and weight estimation results, it was confirmed that the proposed fuel system agreed well with the design specifications and target reliabilities required by the vehicle system.

Research limitations/implications

In current preliminary design phase, the most important consideration is the reliability of the fuel system. Therefore, the weight estimation of the designed fuel system to meet this reliability requirement could not meet partially the system's requirements. In the next design step, the proper fuel system for weight reduction will be performed through an optimization process between weight and reliability.

Originality/value

A specific design procedure components' sizing to meet system requirement target reliability for UAV vertical take‐off/landing was proposed.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 12 September 2016

De-Xing Peng

This paper aims to evaluate the effect of biodiesel additive in fuel system of diesel engines to reduce wear characteristics. Biofuels are environmentally friendly and…

Abstract

Purpose

This paper aims to evaluate the effect of biodiesel additive in fuel system of diesel engines to reduce wear characteristics. Biofuels are environmentally friendly and renewable alternatives to mineral-based fuels and cause low pollution; thus, they can be used to comply with future emission regulations to safeguard environmental and human health.

Design/methodology/approach

Two types of diesel fuel, pure petrodiesel and soybean oil, were compared for their fuel properties and tribological performance. The ball-on-disk wear testing method was used as an analytical tool for this purpose. The lubricating efficiency of the fuels was estimated using a photomicroscope to measure the average diameter of the wear scar produced on the test ball.

Findings

The wear experiments showed that the wear scar diameters were 1.13 and 0.94 mm for lubrication of the pure petro-diesel and soybean oil, respectively. However, fatty acids containing biodiesel typically have thicker molecular layers than mineral pure petro-diesel, and thus can reduce the wear rate of the sliding metals. This improved the boundary lubrication conditions and the lubricity of the fuel. Biodiesel fuels are effective lubricity enhancers and have greater lubricity enhancing properties than petro-diesel.

Originality/value

The ability of biodiesel to be highly biodegradable and its superior lubricating property when used in compression ignition engines make it an excellent fuel. Biofuel is an attractive alternative fuel to various energy sectors, particularly the transportation sector. Biofuel has immense potential for use in a sustainable energy mixture in the future.

Details

Industrial Lubrication and Tribology, vol. 68 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 June 1980

John Butson

The declared aim of this paper is to explore the possible effects of the need for energy conservation (and in particular the need for economy in the use of oil‐based fuels

Abstract

The declared aim of this paper is to explore the possible effects of the need for energy conservation (and in particular the need for economy in the use of oil‐based fuels) on road vehicle development in the UK over the next few decades. In the absence of the author, his colleague, R J Francis, also of Harwell, presented this paper at the conference held by the Institute of Management Services in London, September 1980. He stressed the fact that the views here are those of ETSU, and may not necessarily be regarded in any way as “government policy”. ETSU is the Energy Technology Support Unit, which is based at Harwell, and was established in 1974 to formulate and manage research, development and demonstration programmes in the technology of renewable energy sources and conservation under contract to the Department of Energy. There are approximately 45 professional staff at ETSU (mainly scientists and engineers) working in three main areas: strategic planning of research and development, management of R&D on the renewable energy sources, and research, development and demonstration in energy conservation. When introducing this paper, Richard Francis said that it set out to establish the need for conservation in general, as well as to explain how this is to be achieved in practice. This subject, he commented, leads on to the special task of improving fuel economy and achieving wider fuel flexibility within road transport, which itself has wide implications for road vehicle technology. This paper reviews all the more realistic alternatives, and then attempts to identify those which seem most promising and also to quantify the impact they might have in reducing our dependence on oil‐based fuels.

Details

Retail and Distribution Management, vol. 8 no. 6
Type: Research Article
ISSN: 0307-2363

Article
Publication date: 3 April 2007

Elena Carcadea, H. Ene, D.B. Ingham, R. Lazar, L. Ma, M. Pourkashanian and I. Stefanescu

This paper aims to present a three‐dimensional computational fluid dynamics (CFD) model that simulates the fluid flow, species transport and electric current flow in PEM…

4037

Abstract

Purpose

This paper aims to present a three‐dimensional computational fluid dynamics (CFD) model that simulates the fluid flow, species transport and electric current flow in PEM fuel cells.

Design/methodology/approach

The model makes use of a general‐purpose CFD software as a basic tool incorporating fuel cell specific submodels for multi‐component species transport, electrochemical kinetics, water management and electric phase potential analysis in order to simulate various processes that occur in a PEM fuel cell.

Findings

Three dimensional results for the flow field, species transport, including waster formations, and electric current distributions are presented for two test flow configurations in the PEM fuel cell. For the two cases presented, reasonable predictions have been obtained, and this provides an insight into the effect of the flow designs to the operation of the fuel cell.

Research limitations/implications

It is appreciated that the CFD modeling of fuel cells is, in general, still facing significant challenges due to the limited understanding of the complex physical and chemical processes existing within the fuel cell. The model is now under further development to improve its capabilities and undergoing further validations.

Practical implications

The model simulations can provide detailed information on some of the key fluid dynamics, physical and chemical/electro‐chemical processes that exist in fuel cells which are crucial for fuel cell design and optimization.

Originality/value

The model can be used to understand the operation of the fuel cell and provide and alternative to experimental investigations in order to improve the performance of the fuel cell.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 June 1998

Terry Ford

Explains the fuel system of the Boeing 777‐200 aircraft. Looks at the system’s features, the fuel feed, the fuel jettison and the flight deck displays in terms of the fuel system.

2728

Abstract

Explains the fuel system of the Boeing 777‐200 aircraft. Looks at the system’s features, the fuel feed, the fuel jettison and the flight deck displays in terms of the fuel system.

Details

Aircraft Engineering and Aerospace Technology, vol. 70 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

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