I.N. EgorovG.V. K r e t i n i n Air Force E n g i n e e r i n g A c a d e m y , L e n i n g r a d s k y Av., 40, Moscow, RussiaThe aim of this paper is to discuss a method of the compromise region determination for the multistage axial flow compressor stochastic optimization problems.' This method is based on the 2-D axisymmetrical mathematical model of the compressor and on the new multicriteria optimization procedure. A specific feature of the multicriteria optimization procedure is a possibility to obtain a set of the Edgeworth-Pareto optimal solutions within the frame of single optimization task. The paper presents some examples of the compressor's geometrical parameters multicriteria optimization. K e y w o r d s : m u l t i c r i t e r i a s t o c h a s t i c o p t i m i z a t i o n , m u l t i s t a g e a x i a l f l o w c o m p r e s s o r .

A multicriteria optimization methodology has been discussed to determine time control laws of advanced aircraft gas turbine engines of complex structure. The resulting optimum control laws ensure top improvement of several defined power plant effectiveness criteria in the system of aircraft at transient work modes. The power plant work quality increase effect is attained due to its work process adaptation for numerous requirements from the side of the aircraft. The proposed methodology effectiveness has been shown by the example of optimizing problem solving to determine time control laws of variable elements of short take-off and vertical landing aircraft power plant.

New spatial forms of international economic cooperation are emerging in the region. The region is not homogeneous in terms of socioeconomic development, thus there are certain differences in dimensions and intensity of international cooperation. The author sets out to identify structural characteristics of the Baltic Sea region. This requires studying practices of transnational and transboundary cooperation and possibilities for their adoption in other regions of the world. An important characteristic of the Baltic Sea region is a considerable difference between its coastal territories, the fact that affects the development of multilateral relations. This article examines the most pronounced socioeconomic differences that should be taken into account when forecasting cooperation trends in the region, including those between the Baltic territories of Russia and their international partners.

Constant rise of hot gas temperature is crucial for the creation of modern gas-turbines engines requiring considerable improvement of cooling configurations. A high pressure turbine blade is one of the most crucial and loaded details in gas-turbine engines. A HPT blade is affected by different operational deviations: stochastic fluctuations of inlet parameters and difference in operational parameters for manufactured engines. Combination of these factors makes the task of uncertainty quantification and robust optimization of the HPT blade relevant in modern science. The authors make an attempt to implement robust optimization to the HPT blade of the gas-turbine engine. The two most important areas of the cooling blade (the leading edge (LE) and the blade tip) were taken into account. The operational and the aleatoric uncertainties were analyzed. These uncertainties represent the fluctuations in the operational parameters and the random-unknown conditions such as the boundary values and or geometrical variations. Industrial HPT blade with a serpentary cooling system and film cooling at the LE was considered. Results of many engine tests were applied to construct probability density function distributions for operational uncertainties. More than 100 real gas-turbines were examined. The following operational uncertainties were reviewed: inlet hot gas pressure and temperature together with cooling air pressure. The tip gap was used as geometrical variation. Conjugate Heat Transfer computations were carried out for the temperature distribution obtained. Geometrical variations of the LE film cooling rows and the tip gap are variables in the robust optimization process. The authors developed a special technology for full parameterization of the LE film-cooling rows only by two parameters. A surrogate model technique (the response surface and the Monte-Carlo method) was applied for the uncertainty quantification and the robust optimization processes. The IOSO technology was employed as one of the robust optimization tools. This technology is also based on the widespread application of the response surface technique. Robust optimal solution (the Pareto set) between cooling effectiveness of the leading edge and the blade tip and aerodynamic efficiency was obtained as the result. At chosen point from the Pareto set (angle point) we calculated necessary levels of robust criteria characterized LE and blade tip cooling effectiveness and kinetic energy losses.

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