Papers by Keyword: Combustion Chamber

Abstract: Timber is one of the most basic building materials. Even if timber has positive technical properties, there are still many limitations to use wooden building elements in the Czech Republic. It’s necessary to fulfil requirements of normative regulations and prove the required properties before using timber structures in buildings. This paper presents the results of laboratory experimental testing on a timber frame structure. The experiment is based on fire resistance testing in the combustion chamber. The article is also focused on the comparison of types of board edge joints and their influence on fire resistance. The measured data are also compared with fire tests according to normative regulations. The tested structure was classified based on the limit states of fire resistance.

Abstract: Wood is a natural anisotropic material that is used in building construction because of the advantageous properties of wood. Speed of construction and the final price of the building represent the main advantages of timber houses. On the other hand, the main disadvantage of these buildings can be the low fire resistance due to the flammable properties of natural wood. There are many limitations for designing these kinds of buildings in the Czech Republic. The limitations are presented in the standards and laws of the CR. This article focuses on the comparison of the methods for testing structures using timber construction elements. The paper presents and compares experimental testing results of a timber structure’s fire resistance in a combustion chamber.

Abstract: The heat-loaded part of the combustion chamber of a liquid rocket engine are Considered. The proposed coating has several layers: an internal metal coating that contacts the part or substrate, and an external coating made of a mixture of ceramic granules and metal powder. At the same time, to obtain the initial surface for coating with the required surface layer roughness, it is proposed to use the method of sand blasting. The article analyzes possible mechanisms of material formation for "base-coating" transition zones, as well as the influence of their chemical composition on the adhesive strength of layers.. The choice of brand and combination of materials used for coating is justified. Technological modes that have been tested in production conditions when applying heat-resistant coatings to parts of modern rocket engines are proposed. The influence of technological parameters of the initial surface preparation process and the geometry of the resulting micro-relief of the substrate on the adhesion characteristics of a multilayer coating made of heat-protective materials operating in the high-temperature zone of the combustion chamber of liquid rocket engines is revealed.

Abstract: In this paper are presented some CFD results regarding combustion in an aircraft turbojet engine, for aviation fuels consisting of hydrocarbon mixtures. Recent achievements in chemical kinetic modeling of kerosene combustion are presented. Performance parameters investigated were combustion efficiency, unburned hydrocarbons as well as liner temperatures and smoke. The analysis is based on the theoretically and experimentally characteristics of a typical axial flow engine.

Abstract: Compression period in a diesel engine is generally seen as initial characteristics before injection into combustion chamber. A free-piston type rapid compression machine (RCM) has been designed simulate the combustion phenomena in order to observe the chemical and physical kinetics studies at elevated pressures and temperatures. Purpose of this study is to clarify the effects of wall cylinder temperature on air heat release, especially during compression period. This method can a light piston is pneumatically shot and gets hammered in stopper at compression end. Measurements were made on a light piston compress in a rapid compression machine (RCM) with intended to simulate the actual compression period related phenomena. During this phenomena, the ambient temperature influences from the cylinder wall temperature has appear beneficial for the biodiesel fuel premixing and achieving best mixture preparation There are three tests will used to investigate the effects of the variant temperature of wall cylinder during compression period. Results show high temperature on cylinder wall will be effects decrease during temperature drop after compression stroke. The new characteristics rapid compression machine (RCM) is to develop and analyse before combustion process.

Abstract: Many metals, such as titanium and superalloys, are used for a wide range of aerospace applications, which include aircraft gas turbine engine and space launcher propulsion engine. In order to manufacture a stiffened extension with superplastic blow forming at elevated temperature, the structural integrity of the joint part was investigated since the welded or bonded joint of internal channels should maintain its strength during superplastic blow forming process. Various types of joint methods were performed in order to investigate microstructural and mechanical properties of the bonded specimen at elevated temperature. In this paper, the possibility of manufacturing combustion chamber and other aerospace components with superplastic blow forming of titanium and superalloy was demonstrated. An innovative manufacturing method to produce complex configuration from titanium multi-sheets by superplastic forming with low hydrostatic pressure was presented. The result also shows that the manufacturing method with superplastic blow forming of multi-sheets of IN718 alloy has been successfully demonstrated for near net shape forming of subscale nozzle extension cone with internal channels.

Abstract: Reduction of diesel engine emissions is now getting more and more focuses from automobile manufacturers as the legalization is becoming stricter. In this paper we use AVL FIRE to simulate and analyze the influence of ω-type combustion chamber shapes on raw emissions of a diesel engine. We get the conclusion that the trend of original exhausts, NOx and soot, decreases without power loss with the ratio TDD of throat diameter and depth of the chamber reducing. And considering the original emission control technologies of the experiment engine, a smaller ratio TDD will contribute to better emission.

Abstract: Based on the entity model of the type 4B26 diesel engine, calculated by CFD FIRE and combined with the software BOOST for the initial boundary conditions, the influence of combustion chamber structural parameters, such as boss height, surface-volume ratio and diameter-depth ratio of combustion chamber, on in-cylinder flow field of diesel engine was investigated. The results show that the influence of the boss height on flow field in the cylinder and the transient swirl ratio is obvious, and increasing the boss height is beneficial to urge the formation of mixture rapidly. Reducing the surface-volume ratio is beneficial for improving the maximum transient swirl ratio, and the air strength maintains well also, but has little influence to the retentivity of the swirl intensity. Meanwhile, reducing the diameter-depth ratio does not only improves the air flow movement strengthen in the combustion chamber, but also enhances the maximum transient swirl ratio, and the retentivity of swirl flow movement is satisfying.

Abstract: In order to assess the rationality of the combustion chamber structure of 2.0L diesel engine equipped with high pressure common rail system, evaluation methods of the interior flow dynamic characteristics was put forward .And numerical simulation was carried out on the effect of different combustion chamber structure matching different fuel injection system parameters on the transient distribution of velocity field, concentration field, temperature field. The results show that: the suggested evaluation method in the combustion chamber structure design is reasonable; and for certain injection system, reasonable design and optimized combustion chamber structure parameters are used to organize air flow characteristic effectively. These are important measures to realize energy conservation and emission reduction on diesel engines.

Abstract: The CNG engine in this paper is developed based on a prototype diesel engine platform. In this paper by analyzing the combustion of the CNG engine under different compression ratio with the FIRE software, we could see that the model which compression ratio is 11 could meet the load needs and the economic needs. At the same time the heat load could meet the requirements of the prototype diesel engine.