Improving the computational accuracy of the dynamic electro-geometrical model using numerical solutions.

Area of Science:

• Electrical Engineering
• Computational Electromagnetics
• Lightning Protection

Background:

• The dynamic electro-geometrical model (DEGM) is used to predict lightning strike probability on structures.
• Traditional DEGM computations are time-consuming and resource-intensive.
• Numerical errors, like discretisation effects, can impact DEGM accuracy.

Purpose of the Study:

• To investigate computational numerical errors in DEGM striking distance calculations.
• To propose an improved DEGM (IDEGM) for faster and more accurate lightning strike prediction.
• To validate the IDEGM's performance on different structural configurations.

Main Methods:

• Analyzing sources of numerical errors in DEGM striking distance computation.
• Implementing a conversion factor and eliminating ground surface points to optimize DEGM.
• Testing the IDEGM on a floating roof tank and a cuboid structure with varying air termination systems.

Main Results:

• The IDEGM reduced computation time from over 14 hours to approximately 6 minutes for a cuboid structure.
• An interception efficiency of 61% was achieved for a cuboid with a central air termination.
• An alternative configuration using catenary wires achieved a 99.1% lightning interception efficiency.
• Calculated strike probabilities closely approximated published results, confirming model accuracy.

Conclusions:

• The IDEGM significantly reduces computational time for lightning strike analysis.
• The IDEGM provides accurate predictions of lightning strike probability.
• The IDEGM offers a more efficient approach to lightning protection design.