Preliminary Design Codes for Water/Tidal Turbines:
Project instructions:
The aim of this thesis is to validate current water turbine design with experimental and software data. The document I have done so far already contains a third of the thesis and should include in the Literature review (feel free to add anything I would have forgotten):
1. Fundamentals of kinetic energy conversion in air and water
2. Lift based systems vs Drag based systems for Kinetic Energy conversion
3. Rotor types
4. Determination of aerofoil characteristics required for wind turbines, both structural and aerodynamics e.g:
-Thickness
-Chordwise location of maximum thickness
-Lift/Drag
-Stall behaviour
-Surface roughness
-Cmc/4 for blade torsion reduction
-Off design performance for gust loading
5. Commonly used HAWT aerofoils and sources of experimental data for them that can be used for validation: (NREL and Sandia have lots, NREL Phase VI turbines are ideal).
6. Determination of aerofoil characteristics for tidal turbines
-Thickness
-Chordwise location of maximum thickness
-Lift/Drag
-Stall behaviour
-Surface roughness
-Cmc/4 for blade torsion reduction
-Cavitation
7. 3D Design aspects of tidal and wind turbines e.g:
-Hub Design
-Hub Diameter
-Blade Diameter
-For tidal, Proximity of tip to sea/ river bed and surface
-Tip speed ratio
8. Tool for aerofoil performance assessment (it should describe,evaluate and give the limitations of the software):
-Xfoil/Rfoil
-CFD
-WT_Perf
-AirfoilPrep
9. Available design tools for wind turbine and tidal turbine including B.E.M Theory (similarly it should also describe evaluate and give limitations)
-QBlade
-OpenProp
-FAST
-G.H Tidal Bladed (if possible)
-YawDyn
Meeting with the supervisor and the guidelines for the analysis will be as follow:
Analysis: Evaluation of the design with software and confirmed with experimental data.
1-Using an aerofoil identified in the identified in the literature review (NREL Phase VI) for which experimental data has been found.
2-Import aerofoil in the software, Run inbuilt Xfoil analysis to determine the pressure distribution and create a polar for a representative angle of attack and speed determined in literature review.
3-Compare with experimental results
4-Extrapolate the polar to 360 deg. Create a blade in the software using data identified in the literature review. (a comparison between QBlade predictions and data found in literature review can be made).
5-Run the Rotor B.E.M simulation over an appropriate range of tip speed ratios identified in literature review.
6-Repeat the process gradually changing the span of the rotor to examine the effect of reduced span.
7-Repeat the above process but for Reynolds number appropriate for water in Xfoil analysis.
8-Determine cavitation parameter and assess whether it falls below the critical value determining the peak Cp and so if the aerofoil is suitable.
9-If so, then run the B.E.M analysis with appropriate tip speed ratio, density and viscosity for water. If not, then use the Xfoil inverse design feature to modify the aerofoil to shape that provides acceptable values of cavitation. I have a set of sources that can be sent to ease the writing.