Vol 48, No 2 (2019)

Stirring processes in oscillatory-type plants are considered. The influence of the shape of the moving element on the quality of stirring is studied using computational modeling methods. Further, the power consumed by the plant is assessed. Similarity criteria that allow a well-founded approach to scaling the stirring plants of the type in question are applied to the processes under consideration.

Blade flutter is one of the major problems that designers of modern gas-turbine engines face. As a rule, the flutter of compressor blades is predicted using simplified criteria devised in design organizations based on the experience of designing and refining engines. In this paper a study of the influence of the design parameters on prediction of blade flutter in compressors of gas-turbine engines is presented. Empirical and probabilistic criteria are not applicable to evaluation of the flutter since the parameters in question are not among the decisive parameters for simplified criteria. In this work, a numerical algorithm for prediction of the flutter based on the energy method is used. The algorithm is applicable if the oscillation modes in vacuum are close to the corresponding modes in a flow, a condition that is always met for compressor blades, with the exception of rarely used hollow blades and blades of composite materials. It is shown that the inter-blade tension has a significant influence on the flutter boundaries, while the effect of other design parameters under investigation on the flutter boundaries is insignificant.

A developed design of a thrust bearing is described. This design has been tested in the operation of a specialized mixer of epoxy compounds. The testing of the thrust bearing design has completely confirmed its good tribological characteristics and long service lifetime in the self-lubrication mode.

A method for construction of a monitoring system of the stress—strain state of power equipment based on the functional relations and regression dependences of the stress state on measured parameters is considered. An algorithm for construction of a monitoring system of the stress—strain stress for the elements of equipment subject to the nonstationary actions of a heat carrier with a variable temperature is presented. The results of use of this algorithm to study the stress—strain state of the connecting pipes of shell elements of power plants under operational conditions are given.

A model is proposed for studying the effect of roughness in a lubricated contact between elastic rough surfaces exerted on the characteristics of the lubricating layer. The conditions under which the transition from the elastic-hydrodynamic mode to a mixed friction mode occurred are investigated.

A methodology for defining the rational relative density for a truss core with pyramidal cells is suggested. Examples of computation of the relative density of filler and the angle of the rod to the base are presented.

This article considers application of the advanced morphological approach as a computer-aided innovation (CAI) support system for choosing and evaluating new technology solutions. The main goal of the approach is to expand the range of potential variants and to clusterize and efficiently choose a decision space for synthesis for the purpose of increasing the feasibility of innovative solutions in the design phase. The suggested technique relies on the cluster analysis, theory of sets, and making up a set of rules to maximize the potential level of developed technologies. The application of the approach is shown by several examples. The analysis and choice of technology solutions, fabrication processes, and control systems for microarc oxidation plants and PU foam milling processes are considered.

This article provides a detailed description of an experimental device to study the problems of wear of lip seals in frictional contact with a rotary shaft. The empirical dependences are presented for assessment of the magnitude of the wear of rubber and polyurethane lip seals depending on their lifetime.