NUMERICAL STUDY OF THE EXHAUST GAS FLOW OF TV3-117 TYPE ENGINES IN COMPOSITION WITH A SCREEN - EXHAUST DEVICE

Abstract

The object of research is a screen-exhaust device in the TV3-117 engine of the Mi-8 helicopter. Investigated problem: The problem of equalizing the flow in the exhaust nozzle is solved. As a result of the numerical study, the total pressure losses are calculated and the flow structures in the structural elements of the exhaust nozzle and the screen-exhaust device (SED) are analyzed. Main scientific results: Obtained Gas-dynamic parameters of the flow in the SED flow path are obtained and the verification of injection processes between the working circuits along the path in the SED design is done. Numerical modeling of gas flows in the SED flow path makes it possible to study in detail the characteristics of the flow at any of its points, as well as to determine the values of hydrodynamic losses associated with the formation of a boundary layer and the emergence of separation zones. A constructive method for leveling the gas-dynamic flow is proposed by installing a blade in the form of an aerodynamic profile in a standard engine exhaust nozzle. Two variants of engine nozzles are investigated under the same boundary conditions using a standard exhaust nozzle with and without a blade. The influence of uneven flow in the exhaust nozzle on the nature of the flow in the SED is shown. An insignificant equalization of the flow in the exhaust nozzle using the installed blade led to a decrease in the total pressure loss in the SED by more than 1 %. The area of practical use of the research results: The results of calculations and modeling can be used for computational and experimental studies aimed at improving the flow path of the exhaust nozzle and the screen-exhaust device by the developers of new military aviation equipment or when modernizing the existing helicopter fleet. Scope of application of the innovative technological product: a new screen-exhaust device has been proposed for left and right TV3-117 engines of all types, which can be installed on the Mi-8MSB-V, Mi-8MT, Mi-14, Mi-24 helicopters. It is competitive and has significantly higher technical and economic indicators compared to known analogues.