scholarly journals Research and Development of a Small-Scale Icing Wind Tunnel Test System for Blade Airfoil Icing Characteristics

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Lei Shi ◽  
Fang Feng ◽  
Wenfeng Guo ◽  
Yan Li
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Temperature Stability ◽  
Liquid Water Content ◽  
Test System ◽  
Simulation Software ◽  
Small Scale ◽  
Two Dimensional ◽  
Low Speed ◽  
Spray System

In order to study the icing mechanism and anti-icing technology, a small low-speed reflux icing wind tunnel test system was designed and constructed. The refrigeration system and spray system were added to the small reflux low-speed wind tunnel to achieve icing meteorological conditions. In order to verify the feasibility of the test system, the flow field uniformity, temperature stability, and liquid water content distribution of the test section were tested and calibrated. On this basis, the icing tests of an aluminium cylinder, an NACA0018 airfoil, and an S809 airfoil were carried out, and the two-dimensional ice shape obtained by the test was compared with the two-dimensional ice shape obtained by the numerical simulation software. The results show that in the icing conditions and icing time studied, the parameters of the test system are stable, and the experimental ice shape is consistent with the simulated ice shape, which can meet the needs of icing research.

scholarly journals Comparison of different droplet measurement techniques in the Braunschweig Icing Wind Tunnel

2021 ◽  
Vol 14 (2) ◽  
pp. 1761-1781
Author(s):  
Inken Knop ◽  
Stephan E. Bansmer ◽  
Valerian Hahn ◽  
Christiane Voigt
Keyword(s):  
Wind Tunnel ◽  
Mass Flow ◽  
Liquid Water ◽  
Measurement Techniques ◽  
Wind Tunnel Test ◽  
Cloud Droplet ◽  
Liquid Water Content ◽  
Liquid Droplets ◽  
Spray System ◽  
Phase Doppler Interferometry

Abstract. The generation, transport and characterization of supercooled droplets in multiphase wind tunnel test facilities is of great importance for conducting icing experiments and to better understand cloud microphysical processes such as coalescence, ice nucleation, accretion and riming. To this end, a spray system has been developed, tested and calibrated in the Braunschweig Icing Wind Tunnel. Liquid droplets in the size range of 1 to 150 µm produced by pneumatic atomizers were accelerated to velocities between 10 and 40 m s−1 and supercooled to temperatures between 0 and −20 ∘C. Thereby, liquid water contents between 0.07 and 2.5 g m−3 were obtained in the test section. The wind tunnel conditions were stable and reproducible within 3 % standard variation for median volumetric diameter (MVD) and 7 % standard deviation for liquid water content (LWC). Different instruments were integrated in the icing wind tunnel measuring the particle size distribution (PSD), MVD and LWC. Phase Doppler interferometry (PDI), laser spectroscopy with a fast cloud droplet probe (FCDP) and shadowgraphy were systematically compared for present wind tunnel conditions. MVDs measured with the three instruments agreed within 15 % in the range between 8 and 35 µm and showed high coefficients of determination (R2) of 0.985 for FCDP and 0.799 for shadowgraphy with respect to PDI data. Between 35 and 56 µm MVD, the shadowgraphy data exhibit a low bias with respect to PDI. The instruments' trends and biases for selected droplet conditions are discussed. LWCs determined from mass flow calculations in the range of 0.07–1.5 g m−3 are compared to measurements of the bulk phase rotating cylinder technique (RCT) and the above-mentioned single-particle instruments. For RCT, agreement with the mass flow calculations of approximately 20 % in LWC was achieved. For PDI 84 % of measurement points with LWC<0.5 g m−3 agree with mass flow calculations within a range of ±0.1 g m−3. Using the different techniques, a comprehensive wind tunnel calibration for supercooled droplets was achieved, which is a prerequisite for providing well-characterized liquid cloud conditions for icing tests for aerospace, wind turbines and power networks.

scholarly journals Comparison of different droplet measurement techniques in the Braunschweig Icing Wind Tunnel

2020 ◽  
Author(s):  
Inken Knop ◽  
Stephan Bansmer ◽  
Valerian Hahn ◽  
Christiane Voigt
Keyword(s):  
Wind Tunnel ◽  
Liquid Water ◽  
Measurement Techniques ◽  
Wind Tunnel Test ◽  
Cloud Droplet ◽  
Liquid Water Content ◽  
Liquid Droplets ◽  
Spray System ◽  
Phase Doppler Interferometry ◽  
Microphysical Processes

Abstract. The generation, transport and characterisation of supercooled droplets in multiphase wind tunnel-test facilities is of great importance for conducting icing experiments and to better understand cloud microphysical processes such as coalescence, ice nucleation, accretion and riming. To this end, a spray system has been developed, tested and calibrated in the Braunschweig Icing Wind Tunnel. Liquid droplets in the size range of 1 to 150 µm produced by pneumatic atomizers were accelerated to velocities between 10 and 40 m s−1 and supercooled to temperatures between 0 and −20 °C. Thereby, liquid water contents between 0.1 and 2.5 g m−3 were obtained in the test section. The wind tunnel conditions were stable and reproducible within 3 % standard variation for median volumetric diameter (MVD) and 7 % standard deviation for liquid water content (LWC). Different instruments were integrated in the icing wind tunnel measuring the particle size distribution (PSD), MVD and LWC. Phase Doppler Interferometry (PDI), laser spectroscopy with a Fast Cloud Droplet Probe (FCDP) and shadowgraphy were systematically compared for present wind tunnel conditions. MVDs measured with the three instruments agreed within 15 %, and showed high coefficients of determination (R2) of 0.985 for FCDP and 0.799 for shadowgraphy with respect to PDI data. The instruments' trends and biases for selected droplet conditions are discussed. LWCs determined from mass flow calculations are compared to measurements of the bulk phase rotating cylinder technique (RCT) and the above single particle instruments. For RCT and PDI, agreement of approximately 20 % in LWC was achieved, although in individual cases larger deviations depending on the flow conditions were detected. Using the different techniques, a comprehensive wind tunnel calibration for supercooled droplets was achieved, which is a prerequisite to provide well characterized liquid cloud conditions for icing tests for aerospace, wind turbines and power networks.

scholarly journals Wind Turbine Wake Modeling in Accelerating Wind Field: A Preliminary Study on a Two-Dimensional Hill

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 153 ◽  
Author(s):  
Omar M. A. M. Ibrahim ◽  
Shigeo Yoshida ◽  
Masahiro Hamasaki ◽  
Ao Takada
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Turbine ◽  
Wind Field ◽  
Complex Terrain ◽  
Wind Farm ◽  
Wind Tunnel Test ◽  
Two Dimensional ◽  
Preliminary Study ◽  
Wake Model

Complex terrain can influence wind turbine wakes and wind speed profiles in a wind farm. Consequently, predicting the performance of wind turbines and energy production over complex terrain is more difficult than it is over flat terrain. In this preliminary study, an engineering wake model, that considers acceleration on a two-dimensional hill, was developed based on the momentum theory. The model consists of the wake width and wake wind speed. The equation to calculate the rotor thrust, which is calculated by the wake wind speed profiles, was also formulated. Then, a wind-tunnel test was performed in simple flow conditions in order to investigate wake development over a two-dimensional hill. After this the wake model was compared with the wind-tunnel test, and the results obtained by using the new wake model were close to the wind-tunnel test results. Using the new wake model, it was possible to estimate the wake shrinkage in an accelerating two-dimensional wind field.

0221 In-flight wind tunnel test system of aircraft

2007 ◽  
Vol 2007.7 (0) ◽  
pp. 53-54
Author(s):  
Ryosuke TANOUE ◽  
Sho UMEZAWA ◽  
Yoshitaka SHIMANO ◽  
Osamu KOBAYASHI
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Test System

Experimental and Numerical Investigation of Inflow Turbulence on the Performance of Wind Turbine Airfoils

2013 ◽  
Author(s):  
O. Eisele ◽  
G. Pechlivanoglou ◽  
C. N. Nayeri ◽  
C. O. Paschereit
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Tunnel Test ◽  
Wind Turbine Blade ◽  
Two Dimensional ◽  
Airfoil Surface ◽  
Wind Tunnel Measurements ◽  
Inflow Turbulence ◽  
The Impact

Wind turbine blade design is currently based on the combination of a plurality of airfoil sections along the rotorblade span. The two-dimensional airfoil characteristics are usually measured with wind tunnel experiments or computed by means of numerical simulation codes. The general airfoil input for the calculation of the rotorblade power characteristics as well as the subsequent aerodynamic and aeroelastic loads are based on these two-dimensional airfoil characteristics. In this paper, the effects of inflow turbulence and wind tunnel test measurement deviations are investigated and discussed, to allow considerations of such effects in the rotorblade design process. The results of CFD simulations with various turbulence models are utilized in combination with wind tunnel measurements in order to assess the impact of such discrepancies. It seems that turbulence, airfoil surface roughness and early transition effects are able to contribute significantly to the uncertainty and scattering of measurements. Various wind tunnel facilities generate different performance characteristic curves, while grid-generated turbulence is generally not included in the wind tunnel measurements during airfoil characterization. Furthermore the correlation of grid-generated wind tunnel turbulence with the atmospheric turbulence time and length scales is not easily achieved. All the aforementioned uncertainties can increase the performance scattering of current wind turbine blade designs as well as the generated aeroelastic loads. A brief assessment of the effect of such uncertainties on wind turbine performance is given at the last part of this work by means of BEM simulations on a wind turbine blade.

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