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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 process…

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. 33 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 April 1958

S. Rowden

A relatively recent development in the field of corrosion prevention has been the advent of the volatile inhibitor, although it is true to say that inhibition may occur when the…

Abstract

A relatively recent development in the field of corrosion prevention has been the advent of the volatile inhibitor, although it is true to say that inhibition may occur when the normally volatile inhibitor is in the solid or gaseous state. Inhibitors are chemical substances which will reduce the intensity of the anodic or cathodic reactions. The most important class of chemical agents used function by changing the electrochemical processes occurring at the metallic surfaces, e.g. chromates, nitrites and phosphates.

Details

Anti-Corrosion Methods and Materials, vol. 5 no. 4
Type: Research Article
ISSN: 0003-5599

Article
Publication date: 1 November 1973

K.T. FOULTON

THE RB199 is an advanced three‐shaft augmented turbofan under development by Turbo‐Union Ltd to power the twin‐engined Panavia 200 multi‐role combat aircraft for the air forces of…

Abstract

THE RB199 is an advanced three‐shaft augmented turbofan under development by Turbo‐Union Ltd to power the twin‐engined Panavia 200 multi‐role combat aircraft for the air forces of Britain, Germany and Italy. The turbofan is in the forefront of aero engine technology in the West, and in terms of numbers to be built — in excess of 2,500 — is by far the largest European engine programme to date. Rolls‐Royce (1971), British participant in the project, has described it as “probably the best example of how to co‐operate in Europe”.

Details

Aircraft Engineering and Aerospace Technology, vol. 45 no. 11
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 August 1960

Direct lift for an aircraft is provided by means of two or more fans mounted for rotation about a common axis parallel to the axis of yaw and adapted to be driven in opposite or…

Abstract

Direct lift for an aircraft is provided by means of two or more fans mounted for rotation about a common axis parallel to the axis of yaw and adapted to be driven in opposite or alternate directions. As shown in FIG. 1, part or whole of the exhaust gases of the gas turbine engines 2, 3 may be diverted by means of valves 21–24 into volutes 12 and 15 and used to drive the fans. Referring to FIG. 2, the gases from the volutes discharge through nozzles 113 on to turbine blades 13 mounted on the outside of a peripheral ring carried on the fan blades 6; the gases then pass through fixed guide vanes 19 to the turbine blades 18 mounted on the fan blades 7. By appropriately relating the angles of the blades 6 and 13 on the upper fan and turbine assembly to the angles of the blades 7 and 18 of the lower assembly, an aerodynamic meshing effect is obtained which causes the fans to contra‐rotate at the required rotational speeds without the aid of any mechanical gearing between them. Controllable louvres (not shown) may be provided in the upper and lower surfaces of the ring or fuse‐lage containing the fan assembly and hinged so that they can be closed to fair into the wing or fuselage contours when the fans are not in use.

Details

Aircraft Engineering and Aerospace Technology, vol. 32 no. 8
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 September 1958

A.D. Baxter and S.W. Greenwood

ROCKET and ramjet engines have not the universal application that gas turbines command and possibly on this account they have not had, until recent years, the development effort…

Abstract

ROCKET and ramjet engines have not the universal application that gas turbines command and possibly on this account they have not had, until recent years, the development effort which gave such amazing results in turbine powered aircraft. Nevertheless, they have demonstrated quite dramatically in various parts of the world that they are power plants to be reckoned with. In Great Britain, their value for aircraft was appreciated somewhat belatedly and events have since decreed that the promise they showed should be smothered before it could become a vital fact. On the other hand their importance for missiles was realized at the conclusion of the 1939–45 war, but again they were not encouraged on anything like the scale that present events show would have been justified. Because of this lack of encouragement, British rockets and ramjets, instead of leading the world, as do gas turbines, are struggling hard to provide a modest rate of progress.

Details

Aircraft Engineering and Aerospace Technology, vol. 30 no. 9
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 March 1991

Edgar S. Lower

Guanidine stearate will function as a lubricant for melamine/formaldehyde resins (and guanamine/formaldehyde resins), and glyceryl monostearate can improve the mechanical…

Abstract

Guanidine stearate will function as a lubricant for melamine/formaldehyde resins (and guanamine/formaldehyde resins), and glyceryl monostearate can improve the mechanical properties of the former. Laurie acid can be applied to the production of high grade baking enemel resins in combination with melamine. Stearic acid can be used in the manufacture of melamine resins, e.g. by reaction with formaldehyde and butanol, to give resins for lacquers, and to yield moulding resins. Sodium myristate is usable as a chain transfer agent in the emulsion polymerisation of methyl methacrylate. Copolymerisation of methacrolein dibutyrate and methyl methacrylate has given resins that can be moulded or used in varnishes, and reaction products of stearic acid with methacrylic acid and neodymium oxide has given transparent optical resins. Cellulose laurate can produce extensibilities of nitrocellulose of the order of 100%, and cetyl acetate can act similarly in film, having little tendency to yellowing, but it has also little stability to exterior exposure. When ethylene glycol monmethyl ether acetyl ricinoleate is incorporated into nitrocellulose as a plasticizer, it gives films that are clear, tough and flexible. Stearic acid can act as a stabilizer for nitrocellulose. Lauryl phosphate has been applied as a catalyst in the modification of olefinic petroleum results, by reaction with acrylic resins, and distearyl pentaerythritol diphosphite can function as a heat stabilizer in petroleum resins.

Details

Pigment & Resin Technology, vol. 20 no. 3
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 1 June 1978

Application of the numerical method to the art of Medicine was regarded not as a “trivial ingenuity” but “an important stage in its development”; thus proclaimed Professor…

Abstract

Application of the numerical method to the art of Medicine was regarded not as a “trivial ingenuity” but “an important stage in its development”; thus proclaimed Professor Bradford Hill, accepted as the father of medical statistics, a study still largely unintelligible to the mass of medical practitioners. The need for Statistics is the elucidation of the effects of multiple causes; this represents the essence of the statistical method and is most commendable. Conclusions reached empirically under statistical scrutiny have mistakes and fallacies exposed. Numerical methods of analysis, the mathematical approach, reveals data relating to factors in an investigation, which might be missed in empirical observation, and by means of a figure states their significance in the whole. A simplified example is the numerical analysis of food poisoning, which alone determines the commonest causative organisms, the commonest food vehicles and the organisms which affect different foods, as well as changes in the pattern, e.g., the rising incidence of S. agona and the increase of turkey (and the occasions on which it is served, such as Christmas parties), as a food poisoning vehicle. The information data enables preventive measures to be taken. The ever‐widening fields of Medicine literally teem with such situations, where complexities are unravelled and the true significance of the many factors are established. Almost every sphere of human activity can be similarly measured. Apart from errors of sampling, problems seem fewer and controversy less with technical methods of analysis then on the presentation and interpretation of figures, or as Bradford Hill states “on the application of common sense and on elementary rules of logic”.

Details

British Food Journal, vol. 80 no. 6
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 1 August 1981

R. Foulk

Although the original finish market is quite large, the automotive refinish market is substantially larger in dollar volume, comprising a wide variety of products for automotive…

Abstract

Although the original finish market is quite large, the automotive refinish market is substantially larger in dollar volume, comprising a wide variety of products for automotive refinishing needs. Some of the major products for the refinish market include: 1. primer‐surfacers, 2. synthetic primers, 3. acrylic lacquers, 4. cellulose nitrate lacquers, 5. alkyd enamels, 6. acrylic enamels, 7. sealers, 8. urethane enamels, and 9. speciality products.

Details

Pigment & Resin Technology, vol. 10 no. 8
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 1 August 1983

Americus

The paint industry is not immune to the dual problems of an ever‐decreasing supply of oil and natural gas, coupled with what some would call the predatory objectives of OPEC. The…

Abstract

The paint industry is not immune to the dual problems of an ever‐decreasing supply of oil and natural gas, coupled with what some would call the predatory objectives of OPEC. The paint industry has a need for energy, and this need starts with its raw materials. To be sure, there is today a “glut” of energy. And it is predicted that this glut will exist until the end of 1985. But sooner or later the energy short‐age will be felt, and the paint industry will not be immune.

Details

Pigment & Resin Technology, vol. 12 no. 8
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 1 December 2004

Miah M. Adel

Incineration strengths of hazardous (2.8×108μg/s) and nonhazardous (6.31×108μg/s) materials were found from the quantities to be incinerated, chemical formulas, and the…

2081

Abstract

Incineration strengths of hazardous (2.8×108μg/s) and nonhazardous (6.31×108μg/s) materials were found from the quantities to be incinerated, chemical formulas, and the incineration time. The smoke stack geometry, exhaust dynamics, and different atmospheric stability conditions were used in the Gaussian model to predict the maximum concentration distances of 0.5 to about 6 km at the ground level in the downwind direction. However, trailing edges of some of exhaust distributions were found to extend beyond 120 km under some atmospheric stability conditions. The counties of Jefferson, Lonoke, Pulaski, Dallas, Cleveland, Calhoun, and Grant in the state of Arkansas are more likely to be affected than others. The possible major products in the hazardous incineration exhaust are chlorinated compounds. The results of this study are important to know the areas that fall under comparatively higher concentrations of incineration exhaust for further observations because of its inherent impact upon living beings, crop production, and environmental conditions.

Details

Management of Environmental Quality: An International Journal, vol. 15 no. 6
Type: Research Article
ISSN: 1477-7835

Keywords

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