Scientific results:
The patterns of combustion of kerosene spray under steam gasification conditions have been studied. A gas composition of the final combustion products was analyzed, as well as the completeness of combustion of kerosene when it was sprayed with superheated steam at various parameters for supplying the oxidizer (air) to the gas generation chamber. Analysis of the influence of operating parameters on the quality of burner operation allowed identification of the main patterns. A limit for the minimum supply of oxidizer to the gas generation chamber, after which flame pulsations with its further extinction are observed, has been identified. Based on the experimental data obtained, a parameter for the minimum oxidizer excess coefficient was introduced. This parameter allows one to calculate the minimum required amount of oxidizer supplied to the gas generation chamber and evaluate the possibility of achieving target parameters for the excess oxidizer inside the device. The new information on the optimal parameters of burner operation when burning kerosene spray with forced supply of an oxidizer into the gas generation chamber, ensuring the most complete combustion of fuel with simultaneous low content of toxic components in the exhaust gases, meeting the maximum permissible concentration standards, can be used to verify numerical models in the development of low-emission devices of such a type.
The results of an experimental study of hydrodynamics of stratified and dispersed annular flow in a horizontal tube have been analyzed, including data on the average thickness and roughness of the film in the lower part of the channel, the pressure drop along the channel and the height of liquid rise along the channel walls. The relationship between the parameters has been analyzed. During the transition from a stratified regime to an annular one, the height of the liquid rise along the channel walls increases both with an increase in liquid flow rate and with an increase in the longitudinal pressure drop. Reducing the film roughness in the azimuthal direction creates an azimuthal component of the shear friction stress, which is responsible for lifting and retention of liquid on the tube walls.
Heat transfer in a flowing film of R21 freon on a single-row bundle of horizontal tubes made of aluminum alloys with modified oxide porous coatings was investugated. The shape and sizes of copper particles were determined. Copper particles or clusters are located at a considerable distance from each other and occupy no more than 50% of the surface. The heat transfer coefficients on modified MAO coatings were compared with the results obtained for the surface of tubes with basic MAO coatings in electrolytes of similar compositions, as well as for a smooth metal tube without coating. Additional surface treatment of porous ceramic coatings by deposition of copper particles led to a decrease in heat transfer coefficients in the flowing film as compared to basic MAO coatings. A slight increase in heat transfer coefficients occurs only on the MAO coating deposited in acidic electrolyte.
A series of experiments on the combustion of aviation kerosene dispersed by model aviation injectors was carried out. The measurements were carried out in a section with optical access for testing front-line devices at elevated pressure. For a number of regimes, the position of the flame front in a model combustion chamber under conditions of increased pressure and temperature was analyzed; the most optimal ignition regimes were identified depending on the boundary conditions (oxidizer temperature at the inlet to the combustion chamber, pressure drops in the fuel path and at the front device). As a result of the study, optimal parameters for implementation of characteristic regimes of aviation fuel combustion dispersed by aviation injectors were obtained.
Implementation of research results:
The Laboratory has developed and tested an approach to the experimental diagnostics of kerosene spraying in aircraft nozzles on the basis of high-speed shadow photography, this technology has been tested on aircraft nozzles produced by «UEC–Aviadvigatel» JSC as part of the PD–35 program.
Organizational and infrastructural changes:
The block of the project aimed at researching heat exchange in irrigated bundles of horizontal pipes possesses an experimental bench to study heat exchange during evaporation and boiling of falling films of liquid (R21 freon) on a vertical single-row bundle of horizontal pipes.
Education and personnel occupational retraining:
Over the whole course of the functioning of the Laboratory, undergraduate and postgraduate students have been working as part of the its team, performing their research. Young employees of the Laboratory regularly participate in scientific schools, including delivering presentations. During the existence of the Laboratory, its employees have defended one Doctor of Sciences and two Candidate of Sciences dissertations have been prepared and defended. Internships have been organized at the University of Duisburg–Essen (Germany) and Imperial College London (United Kingdom).
Cooperation:
The laboratory permanently collaborate with the leading scientist’s laboratory at Imperial College London (United Kingdom).
We have established collaborations with the University of Duisburg–Essen (Germany), the Technical University of Berlin (Germany), Tomsk Polytechnic University (Russia) – internships, conducting collaborative experiments and academic seminars.
Scientific research is conducted in active cooperation with other leading research laboratories (Germany, Sweden,United Kingdom, China PR).
