Investigation of Factors Affecting Iced-Airfoil Aerodynamics

Lee, Sam; Bragg, Michael B.

doi:10.2514/2.3123

Cited by 48 publications

(27 citation statements)

References 7 publications

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“…However, these artificial ice shapes increased the maximum lift coefficient and stalling angle of attack in some cases. Such increases run contrary to the recent body of research associated with tall SLD-type spanwise-ridge ice accretion [6][7][8]. Lynch and Khodadoust [9] also provided a comprehensive review of available data for tall spanwise-ridge type ice shapes, most of which show significant aerodynamic penalties.…”

mentioning

confidence: 46%

“…9 and 10. Lee and Bragg [7] researched the impact of ridge location and airfoil type on aerodynamic performance degradation. They found that C l;max was a strong function of spanwise-ridge location between x=c 0:0 and 0.10 for this airfoil.…”

Section: A Full-scale Resultsmentioning

confidence: 99%

“…Numerous investigations into the aerodynamics of tall spanwiseridge ice shapes have been conducted [6][7][8][36][37][38] and the results are very briefly summarized here. As previously mentioned, the salient feature of the tall spanwise-ridge flowfield is the separation bubble that forms downstream of the ice shape.…”

Section: Aerodynamic Classification Of Spanwise-ridge Icementioning

confidence: 99%

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Aerodynamic Simulation of Runback Ice Accretion

Broeren

Whalen

Busch

et al. 2009

1st AIAA Atmospheric and Space Environments Conference

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This paper presents the results of recent investigations into the aerodynamics of simulated runback ice accretion on airfoils. Aerodynamic testing was performed on a full-scale, 72-in.-chord (1828.8-mm-chord), NACA 23012 airfoil model over a Reynolds number range of 4:7 10 6 to 16:0 10 6 and a Mach number range of 0.10 to 0.28. A highfidelity ice-casting simulation of a runback ice accretion was attached to the model leading edge. For Re 16:0 10 6 and M 0:20, the artificial ice shape decreased the maximum lift coefficient from 1.82 to 1.51 and decreased the stalling angle of attack from 18.1 to 15.0 deg. In general, the iced-airfoil performance was insensitive to Reynolds and Mach number changes over the range tested. Aerodynamic testing was also conducted on a quarter-scale NACA 23012 model [18 in. (457.2 mm) chord] at Re 1:8 10 6 and M 0:18, using low-fidelity geometrically scaled simulations of the full-scale casting. It was found that simple two-dimensional simulations of the upper-and lowersurface runback ridges provided the best representation of the full-scale, high-Reynolds-number, iced-airfoil aerodynamics. Higher-fidelity simulations of the runback ice accretion that included geometrically scaled threedimensional features resulted in larger performance degradations than those measured on the full-scale model. Based upon this research, a new subclassification of spanwise-ridge ice is proposed that distinguishes between short and tall ridges. This distinction is made in terms of the fundamental aerodynamic characteristics as described in this paper.

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mentioning

confidence: 46%

Section: A Full-scale Resultsmentioning

confidence: 99%

Section: Aerodynamic Classification Of Spanwise-ridge Icementioning

confidence: 99%

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Aerodynamic Simulation of Runback Ice Accretion

Broeren

Whalen

Busch

et al. 2009

1st AIAA Atmospheric and Space Environments Conference

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“…The flow medium flowing over the airfoil is assumed to be ideal gas. It was found by (Zhou and Hu, 2006) and (Lee and Bragg, 2003) that in the simulation using Spalart-Allmaras model for the of flow field around an airfoil, is more accurate than Standard k-ε and realizable k-ε models. For this reason, the SpalartAllmaras model with a pressure coupled method was preferred for this analysis.…”

Section: Calculation Using Fluentmentioning

confidence: 99%

Degradation of Power Generation Performance due to Effects of Various Ice Shapes and Accretions on Wind Turbine Blades

Bagade¹,

Mo²,

Mazher³

2015

Energy Research Journal

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In today's world, green energy has become a key initiative as an alternative energy resource. Wind turbines are widely used to harvest wind energy in seasonal and cold environments. Although efficient, cold weather conditions negatively affects wind turbine operations due to ice formation. Damage from icing is seen on blade-tips when super-cooled water droplets that form in colder environments rapidly freeze and accumulate. Different forms of ice structures are formed along the leading edge to the trailing edge of the turbine blade and are classified into horn, rime and glaze ice. These various ice structures can cause power losses, mechanical and electrical failures and pose serious safety hazards (e.g., ice throwing). Ongoing efforts have been in place to develop anti-icing and de-icing strategies, but only a few are available on the market. In this computational study using ANSYS 14, a variable pitched National Renewable Energy Laboratory (NREL) and National Advisory Committee for Aeronautics (NACA) airfoils are used to determine the effects of various ice formations along the cord of turbine blade. Ice accretions on turbine blade can cause significant performance issues such as decreased lift and increased drag leading to performance and energy losses. Understanding the flow behavior of iced airfoil is critical in determining what geometric features of ice contributes to the performance degradation and aerodynamic failures in wind turbines. This study may help optimize future designs and implementation of ice mitigations systems to maximize turbine power output.

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“…The results showed that a ridge of ice aft of the boot can lead to large losses in lift, increase in drag and changes in the pitching moments. He continued this study with Lee (2003) to simulate the effects of large-droplet ice shapes on airfoil aerodynamics experimentally. They investigated the influence of simulated supercooled largedroplet ice accretion on a modified NACA 23012 airfoil.…”

Section: Introductionmentioning

confidence: 99%

The effect of droplet size and liquid water content on ice accretion and aerodynamic coefficients of tower legs

Dehkordi

Farzaneh

Dyke

et al. 2013

Atmospheric Research

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An experimental study was conducted to examine the effects of varying the cloud characteristics on ice accretion on tower legs and on the aerodynamic coefficients around the ice-covered legs. First, the variations of droplet size distribution (DSD) and liquid water content (LWC) in vertical and streamwise directions were measured. Then, variations of ice accretion on an angle bar in the same direction as the flow were measured to determine the aerodynamic forces on a tower leg as a function of ice accretion. The ice accretion experiments were carried out under two conditions with different LWCs and air velocities. The drag coefficient was calculated with different masses and ice shapes for the angle bar as obtained in the experiments. The results showed a reduction in the drag coefficient in the vertical direction with increased local LWC and thicker ice accumulation.

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Investigation of Factors Affecting Iced-Airfoil Aerodynamics

Cited by 48 publications

References 7 publications

Aerodynamic Simulation of Runback Ice Accretion

Aerodynamic Simulation of Runback Ice Accretion

Degradation of Power Generation Performance due to Effects of Various Ice Shapes and Accretions on Wind Turbine Blades

The effect of droplet size and liquid water content on ice accretion and aerodynamic coefficients of tower legs

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