Research on a high-precision real-time improvement method for aero-engine component-level model

Abstract

In order to improve the real-time performance of the aero-engine Component-Level Model (CLM) while ensuring accuracy, a method for the Calculation of Thermodynamic Parameters of Working Fluids (CTPWF) based on a Neural Network and Newton Raphson (NN-NR) is proposed. In this method, the enthalpy or entropy under different fuel-air ratio and humidity conditions is mapped to temperature by a neural network, and the mapping output is used as the initial solution of Newton Raphson (NR) iteration. Then, a high-precision solution can be obtained through a few iterations, which avoids the shortcoming that the traditional method uses a fixed initial solution that leads to too many iterative steps. This effectively reduces the number of iterative steps and improves the calculation efficiency. This method is applied to the aero-thermodynamic calculation of each component of an engine CLM, which improves the accuracy and real-time performance of the CLM. The simulation results show that, compared to the traditional method, the proposed method improves the accuracy of the CTPWF and can reduces the single aero-thermodynamic calculation time by 25 % when humidity is not considered and by 47 % when humidity is considered. This effectively improves the real-time performance of the CLM.

Nonlinear System identification of Air turbine rocket engine based on Polynomial nonlinear state space model

“…Component-level models [3,4] A . The nozzle exit area only affects the static pressure at the nozzle exit and does not influence other states, thus it can be considered as an independent loop.…”

“…The ATR engine is a highly complex thermodynamic cycle system characterized by multivariable coupling, strong nonlinearity, and harsh operating conditions such as high temperatures, high speeds, and intense vibrations, posing significant challenges to engine modeling and control. Common white-box models for aeroengines are component-level models (CLM) [3,4] based on thermodynamic cycles, which connect various engine components to establish the thermodynamic relationships between inputs and outputs. However, due to the inherent complexity and high computational cost of CLM, they are not easily applied directly in control system design.…”