CN-122020839-A - Helicopter lightning indirect effect simulation evaluation method

CN122020839ACN 122020839 ACN122020839 ACN 122020839ACN-122020839-A

Abstract

The helicopter lightning indirect effect simulation evaluation method provided by the application provides a simplified method of a complex aircraft model, realizes early prediction and protection design optimization of the aircraft lightning indirect effect, reduces test cost, and improves digital design and verification capability.

Inventors

GU JINGDONG
CAO XI
LIU DAN
WANG SUXIA
GE WENHUI
XU QIANG
WANG YANG

Assignees

中国直升机设计研究所

Dates

Publication Date: 20260512
Application Date: 20251224

Claims (10)

1. A helicopter lightning indirect effect simulation assessment method, the method comprising: Constructing a multi-dimensional electromagnetic model of the aircraft, simplifying the three-dimensional model, and measuring the reserved typical metallized composite material and electromagnetic parameters of the composite material; for the cable harness in the key area, adding an auxiliary block to encrypt and calculate grids, and setting simulated boundary conditions and lightning current access points after the auxiliary block is set; Simulating standard lightning current waveform by adopting double exponential function I 0 is the injected lightning current, and alpha and beta are the rising and decay time of the current; Simulating the distribution influence of the lightning channel height H at 50-200 m and the inclination angle theta at 0-60 degrees on the electromagnetic field of the aircraft by adopting a transmission line model, calculating the distribution of the space time-varying electromagnetic fields E (t) and H (t), and outputting the space time-varying electromagnetic fields E (t) and H (t) as excitation sources of subsequent field-line coupling; A cable bundle model is led in electromagnetic software, and a field-line coupling algorithm is applied to calculate cable interruption induction voltage V induced (t)/current I induced (t); And establishing an equivalent circuit model of the key electronic and electric equipment, inputting the obtained induction signals into the circuit model to perform transient simulation, simulating the propagation condition of conduction interference in the equipment, and outputting overvoltage or overcurrent waveforms of the key circuit.
2. The method according to claim 1, wherein the method further comprises: And carrying out risk quantification and protection design optimization, comparing the coupled interference signals with equipment sensitivity thresholds, identifying high-risk areas, and automatically iterating and optimizing shielding/grounding design.
3. The method of claim 1, wherein the composite material requires a property of anisotropic properties in the direction of lamination to be specified.
4. The method of claim 1, wherein the electromagnetic parameters include electrical conductivity, magnetic permeability, and permittivity.
5. The method of claim 1, wherein the nose radome is an in-point and the nose landing gear is an out-point, the nose radome is an in-point and the rear landing gear is an out-point, the nose radome is an in-point and the tail blade is an out-point, the main blade is an in-point and the nose landing gear is an out-point, the main blade is an in-point and the rear landing gear is an out-point, and the main blade is an in-point and the tail blade is an out-point.
6. The method of claim 1, wherein the applying a field-line coupling algorithm to calculate the cable break induced voltage V induced (t)/current I induced (t) comprises: and calculating the induction current of the cable shielding layer by using a Taylor model or an Agrawal model, calculating the core wire induction voltage by combining a transfer impedance Z T (f) model, and outputting the time domain induction voltage V induced (t)/current I induced (t) of each cable terminal.
7. The method of claim 1, wherein the auxiliary block should not participate in the simulation calculation to reduce the carry-in error, and the auxiliary block should be set to be disregarded by the calculation means.
8. The method of claim 1, wherein the simplifying the three-dimensional model comprises: On the premise of ensuring that the accuracy of the simulation result is not affected, the three-dimensional model is simplified for improving the calculation efficiency.
9. The method according to claim 1, wherein the method further comprises: the current A component is used in the first time of the back striking in the simulation, and the D component can be overlapped in the subsequent time of the back striking for multi-striking scene analysis.
10. The method according to claim 1, wherein the method further comprises: If the mature cable bundle model cannot be imported, when the NODE point is set and the Segment is generated, the actual model of the cable is required to be strictly referenced for setting, the trend and curvature of the cable are ensured to be consistent with the actual cable laying mode, and the uncertainty of simulation is reduced.

Description

Helicopter lightning indirect effect simulation evaluation method Technical Field The application belongs to the technical field of electromagnetic compatibility and lightning protection of aircrafts, and particularly relates to a helicopter lightning indirect effect simulation evaluation method. Background The indirect lightning effect means that when lightning hits an aircraft, strong electromagnetic pulses (LEMP) invade cables of on-board electronic and electrical equipment or core devices inside the equipment, etc. in an inductive or conductive coupling manner, leading to a system failure. Traditional evaluations rely only on high cost lightning tests (e.g., meeting the DO-160G standard) for long periods and difficult to cover the entire scene, or only simple simulation analysis without a reasonable approach to model simplification. The defects of the prior art include high cost of a test method, failure to provide iterative optimization in an early design stage, neglecting structural details by a simplified simulation rule, such as failure to classify a fuselage structure in layers, failure to consider actual fuselage cable layout on a machine, insufficient precision, failure to integrate full-link analysis of electromagnetic field-circuit coupling, equipment sensitivity threshold and the like. Disclosure of Invention The invention aims to provide a high-efficiency and high-precision digital simulation method, provides a simplified method of a complex aircraft model, realizes early prediction and protection design optimization of an aircraft lightning indirect effect, reduces test cost and improves digital design and verification capability. The application provides a helicopter lightning indirect effect simulation evaluation method, which comprises the following steps: Constructing a multi-dimensional electromagnetic model of the aircraft, simplifying the three-dimensional model, and measuring the reserved typical metallized composite material and electromagnetic parameters of the composite material; for the cable harness in the key area, adding an auxiliary block to encrypt and calculate grids, and setting simulated boundary conditions and lightning current access points after the auxiliary block is set; Simulating standard lightning current waveform by adopting double exponential function I 0 is the injected lightning current, and alpha and beta are the rising and decay time of the current; Simulating the distribution influence of the lightning channel height H at 50-200 m and the inclination angle theta at 0-60 degrees on the electromagnetic field of the aircraft by adopting a transmission line model, calculating the distribution of the space time-varying electromagnetic fields E (t) and H (t), and outputting the space time-varying electromagnetic fields E (t) and H (t) as excitation sources of subsequent field-line coupling; A cable bundle model is led in electromagnetic software, and a field-line coupling algorithm is applied to calculate cable interruption induction voltage V induced (t)/current I induced (t); And establishing an equivalent circuit model of the key electronic and electric equipment, inputting the obtained induction signals into the circuit model to perform transient simulation, simulating the propagation condition of conduction interference in the equipment, and outputting overvoltage or overcurrent waveforms of the key circuit. Preferably, the method further comprises: And carrying out risk quantification and protection design optimization, comparing the coupled interference signals with equipment sensitivity thresholds, identifying high-risk areas, and automatically iterating and optimizing shielding/grounding design. Preferably, the composite material requires an anisotropic property in the direction of lamination to be clarified. Preferably, the electromagnetic parameters include electrical conductivity, magnetic permeability and dielectric constant. The nose radome is an in-point, the nose landing gear is an out-point, the nose radome is an in-point, the rear landing gear is an out-point, the nose radome is an in-point, the tail blade is an out-point, the main blade is an in-point, the nose landing gear is an out-point, the main blade is an in-point, the rear landing gear is an out-point, and the main blade is an in-point, and the tail blade is an out-point. Preferably, the calculating the cable break induced voltage V induced (t)/current I induced (t) using the field-line coupling algorithm includes: And calculating the induction current of the cable shielding layer by using a Taylor model or an Agrawal model, calculating the core wire induction voltage by combining a transfer impedance Z T (f) model, and outputting the time domain induction voltage V induced (t)/current I induced (t) of each cable terminal. Preferably, the auxiliary block should not participate in the simulation calculation, reducing the carry-in error, and the auxiliary block should be set to be free of