What is Vortex Induced Vibration?
When cables are deployed underwater or towed behind vessels, they are exposed to Vortex-Induced Vibration (VIV), also known as strumming.
VIV is caused by Vortex Shedding (Kármán Vortex). As water flows past a cable at speeds close to its natural resonance, vortices form and detach alternately on either side.
These alternating low-pressure vortices induce side-to-side oscillations of the cable.
Problems Caused by VIV
- Increased hydrodynamic drag
- Increased axial tension
- Accelerated cable fatigue
- Hydrophone interference
Concept Cables Ltd has developed an innovative solution to mitigate VIV in subsea cables, ensuring stability, durability, and operational efficiency in challenging underwater environments.
How Concept Cables Suppresses VIV using Integrally Straked Cables
VIV is suppressed through the addition of integral trailing or helical fins (strakes) on the cable surface. These strakes disrupt the formation of Karman Vortices, stabilizing the cable and reducing vibration. Using advanced computer control, Concept Cables can precisely optimize the pitch, direction, and frequency of strakes for specific cable types and hydrodynamic conditions.
Concept Cables Straked Solution
By integrating strakes directly into the cable jacket, Concept Cables provides a durable, low-maintenance, and highly efficient solution to VIV, outperforming alternative methods in both performance and cost-effectiveness.
Integral Strakes
- Reduced cable drag
- No bio-fouling
- No winch fouling
- Extended operational life
- Optimized, custom design
- Cost-effective
Strake Profiles Available
- Fully Helical Continuous spirals for steady suppression
- Reverse Helical Alternating direction for improved stability
- Sinusoidal Wave-like profile for specialized applications
Variable Pitch Strakes Can be applied to counter inherent cable resonance at certain towing speeds.
Comparision of VIV Suppression Options
Hairy Fairings
- Increased cable drag
- Prone to bio-fouling
- Easily damaged
- Can foul in winch gear
Clamp-on Strakes
- High cost
- Loss of cable flexibility
- Unsuitable for repeated deployment and recovery
Ribbon or Bristle Fairings
- High cost
- Easily damaged in winch gear
Benefits of Concept Cables Solution
- Durable Resistant to damage and fouling
- Reliable No risk of detachment during operations
- Efficient Minimizes drag while suppressing vibration
- Specific Tailored design per application
We deliver innovative, high-quality, sustainable cable solutions. Rigorously tested, ISO-certified, reliable, and tailored to meet each customer’s precise, long-term needs.
