Evaluating Aero-Engine Cable Harness Shielding Effectiveness Against Electromagnetic Noise Using Integrated Digital Models

Aero-engine control systems need to be immune to electromagnetic (EM) noise and function reliably in EM environments during the entire flight to guarantee flight safety. This paper proposes a comprehensive shielding effectiveness evaluation approach using integrated digital models that can capture EM responses induced at physically inaccessible measurement points. This approach begins by constructing models of the control system topology, signal transmission, interconnecting cable harnesses, and electric loadings, all of which are integrated into digital control system models. Digital probes are set up in different layers of cable harnesses and controller interfaces to capture the induced EM responses of interest. EM noise is generated using an EM excitation model to evaluate the shielding effectiveness in EM environments. This paper takes a commercial turbofan engine control system as an example whose airborne cable harness is branchless but has multiple layers of braided harness and cable shielding. EM responses induced in the control system by a unit-magnitude plane wave are captured, over half of which cannot be measured using physical experiments. EM responses captured using the integrated digital models confirm that the proposed approach can not only quantitatively evaluate the shielding effectiveness contributed by every shielding layer, point out the EM frequencies to which the control system is most sensitive but also provide comprehensive insights on every shielding contribution and justify the shielding layer necessity, which is valuable to engine designers and can serve as guidance for optimizing EM noise immunity designs.