Raising Gas-Dynamic Stability Margin of Axial and Centrifugal Compressor Stages by Means of Vaned Diffuser Boundary Layer Control / Dujų Dinaminio Stabilumo Ribos Ašinio Ir Išcentrinio Kompresoriaus Pakopose Didinimas Atliekant Stabilizuoto Difuzoriaus Paribio Sluoksnio Kontrolę

Abstract

Generalised research results that consider the upgradability of axial and centrifugal gas turbine engine compressors by means of gas-dynamic boundary layer control on bladed disks are demonstrated. Active and passive methods are used. Comparative analysis of the results has been carried out. The analysis is purposed to determine the influence of the flow circulation around the aerofoils on the performance of compressor single-row bladed disks with smooth blades and rough blades and under the condition that vortex generators are installed. An increase in the efficiency of aviation gas-turbine engines and in their gas-dynamic stability margin support leads to the enhancement of the parameters and performance of compressors: increase in loading of aerodynamic bladed disks, improvement of their economical efficiency, improvement of margin of the continuous flow around the compressor grids, etc. Airflow in the compressor grid is characterised by the flow region in the flow core and also by the flow regions in the wall boundary layers on the grid blades where shock waves, vortices, air swirls, and flow separation phenomena take place. The principle objective of the work is to research the possibilities of influence on the parameters of the elements of compressors and overall performance of gas-turbine engines via the methods of active and passive flow regulation. Active flow regulation is realised either by rendering the auxiliary gas mass to the blades boundary layer, or by suction (withdrawal) of the boundary layer (its part) from the surfaces of blades. Passive flow around regulation is characterised by influence on the boundary layer by means of energy redistribution in the flow itself. Santrauka Šiuo tyrimu siekiama nustatyti sparno profilio aptekejimo įtaką vienos eiles menčių kompresoriaus su lygiomis ir šiurkščiomis mentemis darbui, esant įdiegtiems sūkurio generatoriams. Pagrindinis darbo tikslas – ištirti kompresoriaus elementų ir bendro dujų turbininių variklių darbo įtaką parametrams, taikant pasyvų ir aktyvų srauto reguliavimo metodus. Padidinus dujų turbininių variklių našumą ir jų dujų dinamikos stabilumo ribas, pagereja kompresorių darbas ir parametrai: padideja aerodinaminių diskų su mentemis apkrova, jie tampa ekonomiškai našesni, padideja nepertraukiamo srauto riba aplink kompresoriaus plokšteles.

Effect of Hysteresis on Efficiency of Compressor Cascades During Streamlining by Unsteady Flows

“…Research of the stalled flows in the cascades is brought about by the necessity of problem solving connected with prediction of the mentioned above flow separation modes occurrence in compressor cascades, definition of ways to extend the range of compressors blade rings unstalled streamlining [1; 2] and increase of their gas-dynamic stability margins [3].…”

Effect of Hysteresis in Axial Compressors of Gas-Turbine Engines

“…As a result, the values of the flow deflection angle and lift force coefficient sharply decrease and total pressure losses and grid aerofoil resistance significantly increase. Research of the occurrence of this process and development of flow separation modes in grids demands solving tasks connected with predicting the aforementioned occurrence of flow separation modes in compressor grids, defining ways to extend the range of the non-separated streamline of the bladed disks of compressors, and increasing their gas-dynamic stability margins (Chang 1979;Tereshchenko et al 2005Tereshchenko et al , 2010Lastivka 2011).…”