Turbulent flow transition in corroded pipelines: when Reynolds numbers mislead

Internal corrosion shifts surface roughness in ways that push transition Reynolds numbers 40–60% below textbook predictions. Field data from 18 months of pigging surveys across three North Sea trunks.

• Flow regime characterisation and transition boundary analysis
• Pressure drop measurement and friction factor correlations
• In-line inspection and pigging data interpretation
• Engineering recommendations for integrity management programmes