ELRT: a lightweight 2D radiative transfer framework for rapid calculation of infrared radiation characteristics of aeroengines

With the advancement of infrared technology, the research on the infrared characteristics of aeroengines has become exceptionally crucial, as these characteristics may have an impact on the stealth capability and operational safety of the aircraft. The traditional three-dimensional Monte Carlo ray tracing (MCRT) method, though precise, is associated with high computational costs and low efficiency. This paper presents a novel approach based on the two-dimensional emitting line theory, namely the emitting line radiative transfer (ELRT) method, for computing the infrared radiation characteristics of aeroengine exhaust nozzles. The ELRT method exploits the axisymmetry of the exhaust nozzle to simplify the problem to two dimensions and establishes models of emitting and receiving lines. By means of photon emission and reception, it simulates the transmission process of infrared radiation, thereby significantly enhancing the calculation speed and efficiency. This method not only reduces the requirement for computing resources but also acquires the infrared radiation characteristics at all angles in a single calculation, being suitable for the initial validation of the model and rapid performance assessment. Additionally, the validity of this method is verified in this paper through comparisons with the experimental data from model tests and the MCRT simulation data of aeroengines. The method proposed herein offers an efficient and economical tool for aeroengine design, particularly applicable to the initial design stage and rapid performance evaluation. Meanwhile, it provides a reference for the development of real-time infrared characteristic monitoring and control systems.