Gasdynamic characteristics of outlet straightener of gte low pressure compressor at underexpunded angles of flow inlet

Abstract

The main hydrodynamic characteristics of the outlet straightener (OS) between LPC and HPC of the GTE have been discussed. OS is a stationary cage of the strait radial profiles which has the functions of the barring set and the guide grid simultaneously. From the hydrodynamics point of view OS should produce the homogeneous outlet flow with the least possible resistance. The main hydrodynamic characteristics of OS may change when the parameters of the outlet flow deviate from the calculated ones which is caused by the GTE operation in transient modes and as well as the heterogeneity of the velocity field at the outlet of the LPC [1] . The aim of the research is to receive a data about the variations of the main hydrodynamic characteristics of the OS as a result of deviation of the inlet flow angle in order to have the possibility to make the highly-efficient straightener and to estimate the efficiency of the gas turbine engine in general. The hydrodynamic characteristics of the OS were numerically investigated using the FLOW VISION fundamentals. The segment of the fully dimensional OS of the stationary gas turbine engine was used as a calculation object. It had two neighboring blades passage with strait radial blade between them. The axis x,y,z of the right angle coordinate system were coincided with circumferential, radial and axial directions, respectively. The calculations were provided by using the datum- model of the FLOW VISION turbulent flow - “ weakly-compressible liquid “ which is based on the standard “k-e model of turbulence”. The obtained results of the numerical calculation reflect the common tendency of debasement of almost all the hydrodynamic characteristics of OS such as the total pressure recovery coefficient, coefficient of the full hydrodynamic losses, condition of the velocity field at the exit and others when the angle of inlet flow slightly increases. They can be useful for the estimation of the reduction of efficiency the gas turbine engine in general.