Support Pylon for a Hydrokinetic Generator

Marine Hydrokinetic Power (MHK) is taking form in many ways across the globe. With a persistent race for discovery of new and innovative ways to harness energy in an environmentally friendly way, there is no shortage of engineering innovation or challenges. A Marine Hydrokinetic energy company is employing underwater generators to generate clean energy from the tidal currents, rivers and man made channels. Water currents provide a steady and predictable source of energy that is in abundance. As the flow of rivers and tides can be predicted up to decades into the future.

An alternative energy company approached Adept to engineer a pylon for their new hydrokinetic generator.  Designing this pylon would be similar to designing a pylon for a wind turbine, but different. The loading constraints would be similar, but the environment would be quite different due to the pylon being submerged in seawater.  This project called for Adept to design a pylon that would be manufactured on a large scale and pass rigorous tests while supporting the turbine in a harsh environment.

The pylon was different than a wind turbine in that it needed to be only 3 meters tall, but similar in that it needed to and a life expectancy of 20 years. The Pylons major technical requirements were to withstand thrust loads of thousands of kilo-Newtons and rotational oscillations from tidal currents.  Adept took the challenge and designed the pylon using special grade of steel with a specific coating that was high strength, waterproof and corrosion resistant.

The pylon was just one more example where Adept was able to tackle a challenging new and innovative system. By applying sound engineering knowledge and judgement the project proved successful; much like designing the Turbine Hub, the Garbage Hauler and the Military Linear Actuator, it was the veteran experience and the depth of understanding concepts in areas like mechanical engineering and fluid dynamics.

Design Parameters

  • Height = 3 meter
  • Environment: Sea Water (Submerged)
  • Material: A572 GR50 Steel
  • Finish: Painted
  • Life = 20 yrs.
  • Thrust Load = 100 kN (22,710 lb)
  • Overturn Moment = 100 kN-m (71,000 ft-lb)

Analysis Overview

  • Bolted Flange
  • Ultimate Strength (FEA)
  • Deflection Angular (FEA)
  • Pressfit and Clearance Stackup
  • Thermal Expansion, Clearance and Interference
  • Bearing Sizing: Compressive Strength
  • Anode Sizing

Fabrication & Inspection

  • Seamless Steel Tubing and Plate
  • Welded: Complete Joint Penetration
  • Machine
  • American Weld Society D1.1M