1 Introduction
2 Complex flow and rotor dynamics
2.1 Dynamic stall and turbine efficiency
2.2 Turbine physics
3 Experimental approach
3.1 Model reduction
3.2 Experimental setup
4 Methodology
4.1 LEGI labs water tunnel
4.2 Experimental model
4.3 Force measurement
SRI six-axis sensor | M3714BP | ||
---|---|---|---|
Strain gauge res. | [\(\Omega\)] | 350 | |
Net forces | F X,Y,Z | [N] | 800,800,1600 |
Net moments | T X,Y,Z | [Nm] | 44,44,44 |
Accuracy X (2 kg) | Read/full scale | [−] | 0.05%/0.009% |
Cross talk X (2 kg) | Read/full scale | [−] | <2%/0.036% |
4.4 Surface and deformation tracking
4.5 Particle image velocimetry
Spectra physics | Millenia Pro 2 SJ | |
---|---|---|
Wave length | [nm] | 532 |
Type | [−] | NdYV04 |
Max. power | [W] | 2 |
Set power | [W] | 0.5 |
Spectra physics | Millenia Pro 2 SJ | |
---|---|---|
Wave length | [nm] | 532 |
Type | NdYV04 | |
Max. power | [W] | 5 |
Set power | [W] | 0.5 |
Camera | Phantom V2511 | |
---|---|---|
Resolution | [px\(^2\)] | 1280 \(\times\) 800 |
Pixel size | [\(\mu\)m] | 28 |
CMOS area | [mm\(^2\)] | 35.8 \(\times\) 22.4 |
Color depth | [bit] | 12 |
Focus | [mm] | 105 |
Max acquisition rate | [fps] | 25,000 |
Set acquisition rate | [fps] | 4,000 |
Lens aperture | [mm] | focus/4 |
Exposure time | [\(\mu\)s] | 50 |
4.6 Hydrofoils
Aluminum alloy | |||
---|---|---|---|
Young’s modulus | E | [Pa] | \(72\cdot 10^9\) |
Density | \(\rho\) | [kg/m\(^3\)] | 2800 |
Tensile strength | \(R_{p0.2}\) | [Pa] | \(450\cdot 10^6\) |
Carbon fiber composite (cg-tec.de) | cg-tec.de | ||
---|---|---|---|
Young’s modulus | E | [Pa] | \(52.7\cdot 10^9\) |
Density | \(\rho\) | [kg/m\(^3\)] | 1600 |
Fiber orientation | [\(^\circ\)] | 0/90 |
Silicone (Wacker) | |||
---|---|---|---|
Elastosil M4600 | |||
Young’s modulus | E | [Pa] | \(6.4\cdot 10^5\) |
Density | \(\rho\) | [kg/m\(^3\)] | 1100 |
Tensile strength | [Pa] | \(7\cdot 10^6\) |