The threat from lightning strike on structures can be broken down into several types, analysed by Opera using differing techniques:
Lightning Threat Applications:
- Electric Field Distribution – Breakdown/flashover
- Electric Field Distribution – Zoning
- Direct Effects – Voltage distribution
- Direct Effects – Current Flow
- Direct Effects – Thermal & Stress
- Indirect Effects – Induced Voltages
- Indirect Effects – Induced Currents
Some examples of these assessments are outlined in illustrations below.
An example of a CFC joint structure, undergoing an Opera Electrostatic/current flow analysis. This can be used to determine distribution of
– Electric field
– Current density
And assess the potential for component heating and arcing.
An example of a whole vehicle simulation. An Opera Electrostatic/current flow analysis is used to assess:
– Electrostatic stress
– Zoning analysis
– Current distribution from direct strike
– Thermal and EM stresses
An example of an Opera electrostatic analysis to assess the treat to a helium airship.
The breakdown in helium is approximately one-third that in air. Hence, manufacturers use braided conductors to reduce internal fields.
In the plots below we are assessing field stress resulting from a constant external applied field.
An example of a threat analysis on a wind turbine blade.
An example of an Opera transient analysis to represent a a strike on a helicopter rotor and hub.
A harmonic analysis might be used to assess indirect effects on aircraft internal structures following a strike on the fuselage.