TURBOSHAFT ENGINE THERMOGASDYNAMIC PARAMETERS CALCULATION METHOD BASED ON BLADE-TO BLADE DESCRIPTION OF TURBOMASHINES. PART II. STAGE AND MULTISTAGE COMPRESSORS PARAMETERS DETERMINATION

Gas Turbine Engine (GTE) operating characteristics such as thrust (or power), specific fuel consumption and other cycle parameters on different regimes, can be determined by engine modeling and applying correspondent calculation method. Its accuracy is the function of the engine’s element maps definition precision. So these maps representations influence for engines investigation results significantly. Main points and equation system for engine performances calculation method were represented in Part I of this article. The method gives an opportunity for the flow path thermodynamical parameters and engine integral values analyzing by using multistage axial blade machines blade-to-blade descriptions. The compressor and gas turbine and parameters are getting by special program modules, adding to the engine operating characteristics investigation program complex. These modules use the flow path and cascade middle radius geometrical parameters as the data for calculation. The goal of this article is the representation of the method for axial stages and multistage compressors performances definition. The calculation technique is based on one-dimensional (1D) multistage axial compressor flow description. Proposed 1D flow analysis method allows to get the multistage axial compressor maps taking into account the blade-to-blade gaps flow bleeding and by-pass. The method including is founded on the thermal and gas dynamic equations and turbomachinery theoretical dependences and empirical functions for losses and deviation angles determination. Besides, the representing method allows to calculate gas dynamic parameters, velocity triangles, angles of attack, evaluate their deviations from optimal values, hydraulic losses. Also, it can show accordance of stages working on different regimes, find the stage, which is a reason for compressor instability, and stall margin. This method can be used in GTE mathematic simulation, founded on blade-to-blade description multistage blade machines or also in multistage compressor designing. The proposed method gives the opportunity to control the stator variable vanes stagger angles control and to analyze its influence for stage and multistage compressor gas dynamic parameters and maps