Are Nearly all Tidal Stream Turbines Designs Wrong
Are Nearly all Tidal Stream Turbines Designs Wrong for the Pentland Firth? Stephen Salter Institute for Energy Systems University of Edinburgh S. Salter@ed. ac. uk www. see. ed. ac. uk/~shs
No names, no pack drill.
EWTEC Patras 1998 Edinburgh vertical-axis, variable-pitch with rim power take off.
. . . just like wind turbines but under water. Frederick Lanchester 1868 -1946 Albert Betz 1885 -1968
Turbine in a duct:
Open flow field Duct
1. 4 B=0. 59 1. 2 CP at peak 1 B=0. 47 Betz Limit 0. 8 0. 6 0. 4 0. 2 0 0. 02 0. 04 0. 06 0. 08 0. 10 0. 12 Froude number 0. 14 0. 16 0. 18 0. 20 Mc. Adam RA, Houlsby GT, Oldfield MLG. Experimental measurements of the hydrodynamic performance and structural loading of the transverse horizontal axis water turbine: part 1. Renewable Energy vol. 59 pp. 105 -114. 2013
O’Doherty DM. Mason-Jones, Morris, O’Doherty. T, Bryne, Pricket, Grosvenor. Interaction of Marine Turbines in Close Proximity. EWTEC 2011
NASA
EWTEC Patras 1998 Edinburgh vertical-axis, variable-pitch with rim power take off.
Flow Impedance The determination of the water to flow despite the introduction of obstacles.
Flow Impedance The determination of the water to flow despite the introduction of obstacles. Ratio of head increase to flow-rate reduction.
Flow Impedance The determination of the water to flow despite the introduction of obstacles. Ratio of head increase to flow-rate reduction.
Flow Impedance The determination of the water to flow despite the introduction of obstacles. Ratio of head increase to flow-rate reduction.
Flow Impedance The determination of the water to flow despite the introduction of obstacles. Ratio of head increase to flow-rate reduction.
Flow Impedance The determination of the water to flow despite the introduction of obstacles. Ratio of head increase to flow-rate reduction.
Laminaria Hyperborea (kelp) are found along the edges of the Pentland Firth at depths up to 30 m. Length can reach 3. 5 metres. Cf = ?
68 mm bob Pentland bed stills. P Hayes. Fisheries Research Aberdeen 2006 -8
Friction coefficients for Fshear = 0. 5 ρ U 2 Cf 6. 165 TW x 0. 04 = 247 GW
GOOGLE IMAGES Mo. D order the stretcher bearers to be at the same end ?
No tip-to-hub velocity reduction No squeezing torque through a bearing. On-line shirt-sleeve access at the surface. Thousands of force lines. Contact-free gutter seal. Lots of space.
Are Nearly all Tidal Stream Turbines Designs Wrong for the Pentland Firth? Stephen Salter Institute for Energy Systems University of Edinburgh S. Salter@ed. ac. uk www. see. ed. ac. uk/~shs
Google images
Google images Speed up x 30 Range up x 6000 Payload up x 20, 000 Cost per ton-mile down ÷ 100
Something for the simpletons
R. A. Mc. Adam , G. T. Houlsby , M. L. G. Oldfield Structural and Hydrodynamic Model Testing of the Transverse Horizontal Axis Water Turbine EWTEC 2011
O’Doherty DM. Mason-Jones A, Morris C, O’Doherty. T, Bryne C, Pricket PW, Grosvenor RI. Interaction of marine turbines in close proximity. EWTEC 2011
No names, no pack drill.
R. A. Mc. Adam, G. T. Houlsby, M. L. G Oldfield. Structural and Hydrodynamic Model Testing of the Transverse Horizontal Axis Water Turbine. EWTEC 2011
- Slides: 49