Determination of Optimal Pulse Current for ArcWelding
The manual and semi-automatic welding by pulse current (pulsing arc) is considered in the article. The advantages of welding by the pulsing arc are found out in comparison with welding by a constant arc. Using energetic calculation taking into account thermal balance at the electrode stub, optimal parameters of modulated current, such as frequency and duration of electrical pulses were established for different welding methods and regimes. By that stabilized heat, which needed for making melting drops, lower the level of metal splash and improve formation of the weld. Bibl. 12 (in English; summaries in English, Russian and Lithuanian).
Determination of pulse current optimal parameters for manual arc welding
Manual welding by pulsing arc (pulse current) is researched in the article. The advantages of welding by pulse current are found out in comparison with the welding by direct current. While using energy calculation and taking into account thermal balance at the electrode stub, optimal parameters of the modulated current, such as frequency and duration of electrical pulses were established for different welding regimes. This stabilizes heat, which is necessary for making melting drops, by lowering the level of metal splash and improves of the weld formation.
Computer-Aided System of Virtual Testing of Gas Turbine Engines
The article describes the concept of a virtual lab that includes subsystem of gas turbine engine simulation, subsystem of experiment planning, subsystem of measurement errors simulation, subsystem of simulator identification and others. The basis for virtual lab development is the computer-aided system of thermogasdynamic research and analysis “ASTRA”. The features of gas turbine engine transient modes simulator are described. The principal difference between the simulators of transient and stationary modes of gas turbine engines is that the energy balance of the compressor and turbine becomes not applicable. The computer-aided system of virtual gas turbine engine testing was created using the developed transient modes simulator. This system solves the tasks of operational (throttling, speed, climatic, altitude) characteristics calculation, analysis of transient dynamics and selection of optimal control laws. Besides, the system of virtual gas turbine engine testing is a clear demonstration of gas turbine engine working process and the regularities of engine elements collaboration. The interface of the system of virtual gas turbine engine testing is described in the article and some screenshots of the interface elements are provided. The developed system of virtual gas turbine engine testing provides means for reducing the laboriousness of gas turbine engines testing. Besides, the implementation of this system in the learning process allows the diversification of lab works and therefore improve the quality of training.