Lightning Strike

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
– Voltage
– Electric field
– Current density
And assess the potential for component heating and arcing.

Surface and free space electric field in a CFC joint

Surface and free space electric field in a CFC joint

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
– Heating
– Thermal and EM stresses

surface current density from direct lightnng strike on a test vehicle

surface current density from direct lightnng strike on a test vehicle

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.

Helium Airship with braided conductors

Helium Airship with braided conductors

An example of a threat analysis on a wind turbine blade.

wind turbine blade potential and electric field

wind turbine blade potential and electric field

An example of an Opera transient analysis to represent a a strike on a helicopter rotor and hub.

current density in rotor and hub from direct strike

current density in rotor and hub from direct strike

A harmonic analysis might be used to assess indirect effects on aircraft internal structures following a strike on the fuselage.

magnetic field from direct lightning strike on the fuselage

magnetic field from direct lightning strike on the fuselage

For further details on Opera please contact us