Vol 12, No 3-1 (2013): Vestnik SSAU
9-15
Method of reduced fuel characteristics and parameters of the operating cycles of heat engines
Abstract
Traditionally mass (kg or moles) or volume fractions of substances and products of combustion or other chemical reactions are used in the processes of thermodynamical and thermal calculations. The process of calculation reveals significant differences in properties of the substances in question according to their calorific value and the amount of air required for complete combustion of the fuel. It is difficult to make a generalized analysis of the properties of products of combustion of various substances as working media of the cycle and heat transfer agents in heat exchangers. At the same time the calculation of combustion and design of gas generators using the idea of fuel reduced characteristics are widely used in steam turbine manufacturing. The feasibility of using these possibilities to calculate the cycles of heat engines is analyzed.
16-24
Modeling direct fuel injection by a multipin nozzle into the ice combustion chamber using CAE/CAD-systems
Abstract
The paper describes a model of a combustion chamber with a multipin nozzle of a four-cycle fourcylinder internal combustion engine. The 3D-model is constructed in the Solid Works and ANSYS Gambit software complexes. The model is then exported to ANSYS Fluent for the calculation of the fuel injection processes.
25-28
Vortex wind power plant
Abstract
Proposed to use the vortex wind power plants to generate electricity for compressor stations of gas pipelines. Designed a three-dimensional model and the numerical calculation of the stator wind-power plant at different operating conditions. The distributions of the flow in the computational domain. The dependence of the parameter values in the calculation of the wind speed around the unit.
29-34
System of pressurization of the fuel tank of a launch vehicle using the heat of generator gas
Abstract
Comparative analysis of heat exchangers of various types is carried out: crossflow, shell- and- tube, plate heat exchangers. Mass- power characteristics of the three types of heat exchangers are calculated.
35-39
Method of calculation and analysis of gas flow aerodynamic indices in a vortex wind power plant
Abstract
The article presents a semi-empirical method for calculating vortex wind plants. The method takes into account the theory of vortex Ranque effect and the provisions of the hypothesis of vortex interaction in swirling gas flows.
40-47
Ensuring efficient operation of roller bearings
Abstract
The paper presents some materials to analyze the causes of loss of efficiency of ground- application GTE roller bearings. The factors that influence the temperature of the bearing ring are analyzed. The efficiency of cooling the bearing parts, especially the outer raceway, as well as the heat-stable characteristics and the method of oil supply are shown to have a significant impact on the roller bearing efficiency.
48-56
Thermal state of a groind-use gas turbine engine stator
Abstract
The paper presents materials on the thermal state of a ground-use gas turbine engine stator. The factors that influence the temperature of the case bands of the turbine nozzles and bearings are analyzed. The efficiency of cooling both from the outside of the base members and by hot gases is shown to have a significant effect on the temperature of the stator.
57-64
Homogeneous burners of two-staged combustion chambers
Abstract
The paper presents materials to provide the metering characteristics of two-staged combustion chambers of gas turbines of terrestrial application. The factors that affect the flow characteristics of burners are analyzed, including the working fluid flow pattern in the vortex chamber of the burner. Significant influence of design features and operating modes of the burners in the engine on the flow characteristics is shown. Flow characteristics of the burners with tangential air inlet into the burner cavity are shown to be influenced by the pressure differential.
65-72
Conditions of compatibility of compressor and turbine used as part of a gas generator required to ensure turbine operability
Abstract
The article shows the necessity of matching joint functioning of the compressor and the combustion chamber at the stage of designing a gas generator to provide the turbine operability and specifies the formula for the calculation of the superficial flow velocity downstream the compressor as a matching parameter which, if its value is provided, prevents gas temperature field instability downstream of the combustion chamber and correspondingly prevents the damage of the turbine blades.
73-78
The influence of swirling of a flow with axial countercurrent on the process of burning of hydrogenoxygen mix in the stream of water steam
Abstract
The paper presents comparative results of the numerical research of the combustion of stoichiometric hydrogen-oxygen mixture in the medium of water steam using various ways of mixing fuel components in the flame tube of a tubular combustion chamber.The geometry of the mixing chamber that makes it possible to achieve the highest values of combustion efficiency and temperature uniformity at the exit of the combustion chamber is defined.
79-86
Comparison of mass properties of high- pressure cylinders with cryogenic fill for a throttle cooling system
Abstract
The paper presents the results of testing a tank with cryogenic fill (liquid nitrogen) conducted at the level of pressure of up to 4 MPa. The behavior of parameters in the tank, the time and pressure are shown to correspond to the design model.
87-92
Evaluating the possibility of using low-temperature thermal energy in liquefied natural gas complexes
Abstract
This paper presents an analysis of the possibility of using the low-temperature thermal energy of liquefied natural gas as applied to the regasification process in an evaporator at a gas distribution station.
93-97
98-102
Interconnection of propagation velocity and electrical conductivity of flame in ICEs
Abstract
Investigation of regularities of interrelation between the local propagation velocity and electrical conductivity of flame with varying composition of the mixture in a spark-ignition engine was conducted. The electrical conductivity and the velocity of flame propagation near the spark plug with the average temperature in the combustion chamber being practically constant vary in the conditions of the experiment carried out. The power dependence between electrical conductivity and propagation velocity of flame is revealed in case the air-fuel ratio changes. This can be described by power dependence. The electrical conductivity of flame is shown to depend on the speed of chemical reactions in confined turbulent combustion. The results of the research can be used to develop methods of diagnosing local intensity of burning in combustion chambers.
103-112
Formation of microvortex gas flows in channels of a block catalyst with coplanar channels
Abstract
The paper deals with the formation of vortex cores and improving the efficiency of an oxidation catalyst. A new design of a catalytic unit is presented. Hydrodynamic calculations and experimental analysis of microvortex currents in the channels of the catalyst are presented. The goals and objectives for future work are identified.
113-117
Correlation and regression model for the assessment of circular non-uniformity of the gas temperature field at the outlet of small gas turbine engine combustion chambers
Abstract
The paper deals with the problems of modeling circular non-uniformity of the gas temperature field (GTF) at the outlet of small gas turbine engine combustion chambers.. Correlation and regression dependence for estimating circular non-uniformity of the GTF is obtained with regard for the dimensions, the range of its application is identified.
118-124
Mathematical model for calculating radial non-uniformity of the gas temperature field at the exit of small gas turbine engine combustion chambers
Abstract
The paper is devoted to the problems of constructing a model of radial non-uniformity of the gas temperature field (GTF) at the outlet of the combustion chambers of small gas turbine engines (SGTE). Correlation regression dependence for assessing the influence of structural and operational parameters on the characteristics of the temperature field at the outlet of SGTEs is obtained.
125-130
Test benches for researching the processes and operational development of low emission gas turbine engine combustion chambers
Abstract
The paper presents a range of test benches that form the base for researching gas dynamic processes the processes of mixture and combustion in the burner of a gas turbine engine combustion chamber, as well as benches for testing full-size combustor chambers both separately and as part of the engine. This base is necessary for the production and optimization of low emission gas turbine engine combustion chambers.
131-138
Analyzing the quality of preparing fuel-air mixture and its influence on NOx in a low emission gas turbine engine combustion chamber
Abstract
The paper presents the results of research carried out to determine the concentration fields in the swirl flow of swirl burners of various design. The burners are used in combustion chambers working on the principle of burning premixed lean air-fuel mixture. The influence of the quality of pre-operation air-fuel mixture on the NOx emission in a gas turbine engine combustion chamber is assessed.
139-145
146-155
Influence of the turbine ignition, flame tube suspension and nozzles on the combustion chamber characteristics
Abstract
The paper presents a mathematical model of the working process of a gas turbine engine combustion chamber that makes it possible to take into account the effect of the flame tube suspension, ignition and turbine nozzles on the working process of the combustion chamber and to estimate the effect.
156-162
Effect of non-uniform compressor flow parameters on the characteristics of a gas turbine engine combustion chamber
Abstract
A mathematical model of the working process of a gas turbine engine combustion chamber is presented which makes it possible to take into account the residual swirl and radial non-uniformity of the flow velocity at the inlet to the combustion chamber.
163-169
Formation of carcinogenic PAHs (polyaromatic hydrocarbons) in the turbulent diffusive flame
Abstract
The paper is devoted to the investigation of forming the PAH spectrum in the process of turbulent diffusion combustion of a propane butane mixture. The parameters that influence the oxidation of hydrocarbons and basic PAHs are generalized in terms of the process of mixing, diffusion, chemical kinetics. Areas of intensive formation of the PAH spectrum are revealed.
170-176
The influence of engineering changes on NOx emission in a gas-turbine endine combustion chamber
Abstract
The paper presents a model of calculating nitrogen oxide formation in the combustion chamber of a gas turbine engine. The model has made it possible to make the calculations and determine the characteristics of nitrogen oxide concentration from the total air ratio in combustion chambers with various extents of opening the flame tube head. The processes in the commercial and shortened gas turbine engine combustor chambers are analyzed.
177-182
Limit values of the Brayton cycle with the use of reduced fuel characteristics
Abstract
Heat energy of fuels used in cycles is a source of reaching useful effect of the heat engine cycle. The maximum effect of using the fuels can be obtained in the cycles of rocket and aircraft engines since, due to their specific nature, they carry the fuel (as well as the oxidizer in rocket engines) during the whole period of performing the mission. The energy and transport power installations are to use the fuel available in the region and reasonably-priced. Taking the most common Brayton cycle as an example we considered factors that determine the maximum coefficient of heat consumption of fuel in the cycle. Two factors are considered restricting the efficiency of the Brayton cycle efficiency: the maximum permissible limit of the strength properties of materials and the maximum level of fuel combustion products. The values of the excess air ratios in the combustion of fuels and the limiting characteristics of heat engines according to the Brayton cycle are determined. The information on the generalized approach to the assessment of the energy properties of the fuels and the impact of this measure on the Brayton cycle is presented.
183-189
Applying the possibilities of Microsoft Excel for solving problems of fuel burning thermodynamics
Abstract
Heat energy obtained from burning fuels is practically the main source of useful effect of the heat engine cycle. To calculate the cycles of heat engines it is necessary to know the temperature and thermodynamic characteristics of the products of combustion that constitute the working substance in the processes of expansion. The solution of the balances of the initial substance masses and those of the masses of products of chemical reactions as well as the power balances of reactions becomes a serious task. In the authors’ opinion Microsoft Excel spreadsheets that make up the compulsory set of software for Microsoft Office computers and laptops are useful for the development of computational methods of reactions of burning at the stage of training students and engineers.
190-196
Test case of 3d unsteady swirling flows modeling using commercial and in-house codes
Abstract
The paper gives the comparison of the results of turbulent flow computational modeling in an experimental rig using various software environments: commercial ANSYS CFX software and original Higher-Order Accuracy Codes. The effects of turbulence models and computational grid size on the computation data are evaluated.
197-205
Characteristics of the sampling instrument for measuring emissions of an aircraft gas turbine engine
Abstract
The paper presents the results of the experimental study of the characteristics of the sampler used to measure the emissions of an aircraft bypass engine. The temperature of the sampler and the sample inside it, the pressure difference in the flow of the gas at the sampler inlets are determined, the emission level being measured starting from the idling mode to the take-off mode. The influence of using a vacuum pump on the sampler’s characteristics is shown. The data obtained are compared with the requirements of the ICAO standard.
206-210
CFD-based modeling of oil ang gas journal bearings using commercial software packages
Abstract
The paper presents a methodology of modeling fixed geometry journal bearings with gas and oil lubrication. The general CFD package ANSYS is employed to simulate cavitated and turbulent flows. A grid independence study is performed for the oil-lubricated bearing. The CFD predictions are compared with the results obtained by traditional methods (reference books and using the Reynolds equation of lubrication). The discussion of the adequacy of the model is provided.
211-221
Combustion of polymers in the electrostatic field
Abstract
The paper presents the results of the experimental study of the influence of an external electrostatic field on the mass burning rate and flame temperature of PMMA, SKD-2, SKN-26, SKMS-30, SKEPT localized in different parts of the combustion zone.
222-229
Simulation of drop coagulations in swirled time dependent streams with reference to gas turbine engine combustion chambers
Abstract
The paper presents a model of fuel drop coagulation with reference to gas turbine engine combustion chambers. Calculations of drop coagulation are carried out at various values of the fuel spray expansion angles and initial drop sizes using the model developed. The values of drop concentrations and their sizes depending on geometrical and performance characteristics of the sprayer are specified. It is shown that the decrease of the fuel spray angle, with the initial drop concentration and their sizes being the same, leads to the shift of the fuel concentration maximum towards larger sizes and increase in drop concentrations.
230-234
Analysis of potentialities of coil electromagnetic accelerators for the accelerating of ferromagnetic particles
Abstract
The paper presents an analysis of coil electromagnetic accelerators. Physical limits on the maximum acceleration imparted to a ferromagnetic body are defined. Mathematical modeling of a single-stage coil electromagnetic accelerator has been carried out including three-dimensional simulation of the particle trajectory. The influence of parameters of traction coils, the initial conditions and the particle material on the final speed is analyzed.
235-247
Development of a generalized model of heat-mass transfer between fuel drops and gas stream with reference to gas turbine engine combustion chambers
Abstract
The paper presents a generalized model of heating and evaporation of separate fuel drops, taking into account the influence of the distribution of fuel steam concentration around the drop on the evaporation process. Numerical calculations for the operations typical for gas turbine engine combustion chambers are presented. The range of air flow temperatures over which the influence of fuel steam concentration in the drop environment on the rate of its evaporation and the fuel distribution in the swept volume of the combustion chamber is significant has been defined.
248-254