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This paper aims to present a novel run time combustion zoning (RTCZ) technique based on the working principle of eddy dissipation concept (EDC) for combustion modeling. This technique selectively chooses cells in which the full reaction mechanism needs to be solved. The selection criterion is based on the concept of differentiating between combustion and the non-combustion zone. With this approach, considerable reduction in computational load and stability of the solution was observed and even the number of iterations required to achieve a stable solution was significantly reduced.

Computational fluid dynamics (CFD) simulations of real life combustion problems such as industrial scale flares, fuel fired furnaces and IC engines are difficult due to the strong interactions of chemistry with turbulence as well as the wide range distribution of time and length scales. In addition, comprehensive chemical mechanisms for hydrocarbon combustion may include hundreds of species and thousands of reactions that are known in detail for only a limited number of fuels. Even with the most advanced computers, accurate simulation of these problems is not easy. Hence, the modeler needs to have strategies to either simplify the chemistry or to improve the computational efficiency.

The EDC turbulence model has been widely used for treating the interaction between turbulence and the chemistry in combustion problems. In an EDC model, combustion is assumed to occur in a constant pressure reactor, with initial conditions taken as the concentration of the current species and temperature in the cell. With these assumptions, EDC solves the full or simplified reaction mechanism in all the grid cells at all iterations.

This paper presents a novel RTCZ technique for improving the computational efficiency, when the EDC model is used in CFD modeling. Considerable reduction in computational time and stability of the solution can be achieved. It was also observed that the number of iterations required to achieve a converged solution was significantly reduced.

In the cylinders of a marine diesel engine, self-ignition occurs in a very short time after the fuel injection into the combustion chamber. Therefore, this paper aims to develop a model of diesel fuel spray for the early stage of fuel spray in the marine diesel engine. The main technical aspects such as nozzle diameter of the marine engine injector and backpressure in the combustion chamber were taken into consideration.

In this paper, laboratory experimental studies were carried out to determine parameters of fuel spray in an early stage of injection in the marine diesel engine. The optical measuring Mie scattering technique was used to record the fuel injection process. The working space was a constant volume chamber. The backpressure parameters in the constant volume chamber were the same as during the operation of the marine diesel engine. Based on the experimental studies and important Hiroyasu and Arai models of fuel spray presented in literature was proposed new model of fuel spray parameters for marine diesel injectors.

In this paper, the proposed new model of the two main parameters described fuel spray evolution”: new model of spray tip penetration (STP) and spray cone angle (SCA). New model propagation of fuel STP in time was included the influence of nozzle diameter and backpressure. The proposed model has a lower error, about 15%–34%, than the model of Hiroyasu and Arai. Moreover, a new model of the evolution over time of the SCA is developed.

In the future research of fuel spray process must be taken influence of the fuel temperature. Diesel fuel has a different density and viscosity in dependence of fuel temperature. Therefore are predicted of the expansion about influence of fuel temperature, new model of fuel spray for a marine diesel engine. The main limitations occurring in the research are not possible to carry out the research while real operation marine diesel engine.

An experimental test was carried out for a real fuel injector of a marine diesel engine. Design parameters and fuel injection parameters were selected on the basis of the actual one. In the literature, SCA is defined as a constant parameter for the specific preliminary data. A new model for the early stage of fuel spray of SCA propagation in time has been proposed. The early stage of fuel spray is especially important, because in this time comes in there to fuel self-ignition.

THE rocket motor is a form of jet propulsion which is characterized by independence of the external atmosphere for combustion, relative independence of altitude and flight velocity upon thrust, small frontal area for high thrusts, simple construction and low weight, and high rate of fuel consumption. Its use was greatly developed during the war years and many applications are now familiar to all. Most of the work on rocket missiles, such as the anti‐aircraft barrages, fighter armament, etc., was performed with solid fuel rockets, but liquid fuels were developed by the Germans for the well‐known V.2, for the Me. 163 aircraft, the Henschel glide bomb and various other applications. They concentrated a great deal of effort on this work and considerable technical progress had been made with different systems. Three main systems emerged and these were distinguished by the oxygen bearing fluids they used. The fluids were:

THIS paper will be confined to oil fuel, which has been used so far to a predominating extent in the gas turbine. It is possible that some of the general matters touched upon will be applicable to gaseous or solid fuels, such as aero‐dynamic patterns within a combustion zone, wall cooling and effects of ash.

The development of a theoretical model for predicting the combustion, performance and emission characteristics of a cylinder head porous medium engine becomes necessary due to imposed requirements from the viewpoint of power, efficiency and toxic gases in the exhaust. The cylinder head porous medium engine was found to have superior combustion, performance and emission characteristics when compared to a conventional diesel engine. The paper aims to discuss these issues.

Due to heterogeneous and transient operation of diesel engine under conventional and porous medium mode, the combustion process becomes complex, and achieving a pure analytical solution to the problem was difficult. Although, closer accuracy of correlation between the computer models and the experimental results is improbable, the computer model will give an opportunity to quantify the combustion and heat transfer processes and thus the performance and emission characteristics of an engine.

In this research work, a theoretical model was developed to predict the combustion, performance and emission characteristics of a cylinder head porous medium engine through two-zone combustion modeling technique, and the results were validated through experimentation.

The two-zone model developed by using programming language C for the purpose of predicting combustion, performance and emission characteristics of a porous medium engine is the first of its kind.

THE second Combustion Colloquium organized by the A.G.A.R.D. (Advisory Group on Aeronautical Research and Development to the N.A.T.O. Countries) was held at the University of Liege, in Belgium, on December 5–9 last, and was attended by about 200 delegates. The seventeen papers which were presented and discussed were grouped under the following headings, although their subject matter sometimes overlapped these boundaries:

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.

IN the year 1890, Herbert Akroyd Stuart took out a British patent in which, for the first time, mention is made of an engine which may be said to bear some resemblance to the modern compression‐ignition engine.

This chapter provided systematic and comprehensive analysis on trawl fisheries management and conservation measures in the Straits of Malacca. Detailed analysis is conducted on Malaysian fishery management framework particularly domestic country's trawl fishery status, legal structure, input-control strategies, ecosystem protection plan, pollution, law enforcement, and complementary measures that designed to reduce and prevent overfishing in the exclusive economic zone (EEZ) of Malacca Straits. Gaps and challenges found in existing trawl fisheries literature are presented followed by recommendations for improvement in the management and conservation of trawl fisheries.