An emerging tidal stream technology is the shrouded tidal turbine that has a turbine that is enclosed in a Venturi shaped shroud or duct (ventuduct) producing a sub atmosphere of low pressure behind the turbine. The venturi shrouded turbine is NOT subject to the Betz Limit and allows the turbine to operate at higher efficiencies than the turbine alone by increasing the volume of the flow over the turbine. Claimed improvements vary, from 1.15 to 4 times higher power output than the same turbine minus the shroud. The Betz limit of 59.3% conversion efficiency for a turbine in an open flow still applies, but is applied to the much larger shroud cross-section rather than the small turbine cross-section.
Read more about Shrouded Tidal Turbine: Principles, Types of Shroud
Famous quotes containing the words shrouded and/or tidal:
“Ah, Sun-flower, weary of time,
Who countest the steps of the Sun,
Seeking after that sweet golden clime
Where the traveller’s journey is done:
Where the Youth pined away with desire,
And the pale Virgin shrouded in snow
Arise from their graves, and aspire
Where my Sun-flower wishes to go.”
—William Blake (1757–1827)
“And now it is once more the tidal wave
That when it was swept by, leaves summits stained.
Oh, blood will out. It cannot be contained.”
—Robert Frost (1874–1963)