scholarly journals Water droplet deformation and breakup in the vicinity of the leading edge of an incoming airfoil

2016 ◽  
Author(s):  
Adelaida García-Magariño García
Keyword(s):  
Water Droplet ◽  
Leading Edge ◽  
Droplet Deformation

Modeling of Droplet Deformation Near the Leading Edge of an Airfoil

2015 ◽  
Vol 52 (6) ◽  
pp. 1838-1846 ◽  
Author(s):  
Suthyvann Sor ◽  
Adelaida García-Magariño
Keyword(s):  
Leading Edge ◽  
Droplet Deformation

Improved Taylor analogy breakup and Clark models for droplet deformation prediction

2017 ◽  
Vol 233 (2) ◽  
pp. 767-775 ◽  
Author(s):  
Zhenlong Wu ◽  
Benyin Lv ◽  
Yihua Cao
Keyword(s):  
Leading Edge ◽  
Surface Tension Force ◽  
Aerodynamic Characteristics ◽  
Viscous Force ◽  
Pressure Force ◽  
Droplet Deformation ◽  
Deformation Prediction ◽  
Clark Model ◽  
Improved Model ◽  
Breakup Model

The deformation of rain droplet at the leading edge of a wing is critical to the aerodynamic characteristics of the aircraft under heavy rainfall and icing conditions. This study introduces the improvement of the Taylor analogy breakup and Clark models for prediction of droplet deformation near the leading edge of an airfoil. The slip velocity is considered as time-variant in the improved Taylor analogy breakup model. The viscous force is optimized in the improved Clark model. The prediction results suggest that the Clark models predict better results than the Taylor analogy breakup models. Besides, the improved Clark model has the highest prediction accuracy. However, considering the Clark model is derived based on a two-dimensional model, even the improved model still has some unavoidable deviations from the real situation. In addition, the simplified surface area in the surface tension force and the approximation of the pressure force in the original Clark model are very effective, thus are kept the same in the improved Clark model.

Effect of droplet deformation on pull-off force of the water droplet on hydrophobic surface

2020 ◽  
Vol 2020.57 (0) ◽  
pp. J021
Author(s):  
Kenji YANAGISAWA ◽  
Yuusuke GOMI ◽  
Gakuto KUROIWA ◽  
Hiroo TAURA
Keyword(s):  
Water Droplet ◽  
Hydrophobic Surface ◽  
Droplet Deformation

scholarly journals Rotating Arm-Based Experimental Study on Droplet Behavior in the Shoulder Region of an Aircraft Aerodynamic Surface

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
S. Sor ◽  
A. García-Magariño ◽  
A. Velazquez
Keyword(s):  
Experimental Study ◽  
Imaging System ◽  
Leading Edge ◽  
Base Flow ◽  
Particle Image Velocimetry System ◽  
Edge Region ◽  
Droplet Deformation ◽  
Droplet Behavior ◽  
Shoulder Region ◽  
Set Up

An experimental study has been performed on water droplet deformation in the shoulder region of an airfoil. The experiments have been carried out in a rotating arm facility 2.2 m long and able to rotate up to 400 rpm (90 m/s). A blunt airfoil model (chord length equal to 0.468 m) was placed at the end of the arm. A droplet generator was used to generate a stream of water droplets with an initial diameter of 1000 μm. An imaging system was set up to record the trajectories and deformations of the droplets in three different regions close to the airfoil shoulder. The base flow field was characterized using a particle image velocimetry system. The experiments show that droplet deformation results in the shoulder region of the airfoil are different from those pertaining to the leading edge region. In particular, droplets in the shoulder region tend to rotate to the direction of the incoming airfoil which generates an interference effect between the droplets that make up the stream. These differences have been quantified applying an existing theoretical model specifically developed for the leading edge region to the results obtained in the present study.

scholarly journals Water Droplet Erosion of Wind Turbine Blades: Mechanics, Testing, Modeling and Future Perspectives

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 157 ◽  
Author(s):  
Mohamed Elhadi Ibrahim ◽  
Mamoun Medraj
Keyword(s):  
Wind Turbine ◽  
Water Droplet ◽  
Prediction Models ◽  
Experimental Testing ◽  
Turbine Blades ◽  
Leading Edge ◽  
Droplet Impact ◽  
Wind Turbine Blades ◽  
Water Droplet Erosion ◽  
Erosion Prediction

The problem of erosion due to water droplet impact has been a major concern for several industries for a very long time and it keeps reinventing itself wherever a component rotates or moves at high speed in a hydrometer environment. Recently, and as larger wind turbine blades are used, erosion of the leading edge due to rain droplets impact has become a serious issue. Leading-edge erosion causes a significant loss in aerodynamics efficiency of turbine blades leading to a considerable reduction in annual energy production. This paper reviews the topic of water droplet impact erosion as it emerges in wind turbine blades. A brief background on water droplet erosion and its industrial applications is first presented. Leading-edge erosion of wind turbine is briefly described in terms of materials involved and erosion conditions encountered in the blade. Emphases are then placed on the status quo of understanding the mechanics of water droplet erosion, experimental testing, and erosion prediction models. The main conclusions of this review are as follow. So far, experimental testing efforts have led to establishing a useful but incomplete understanding of the water droplet erosion phenomenon, the effect of different erosion parameters, and a general ranking of materials based on their ability to resist erosion. Techniques for experimentally measuring an objective erosion resistance (or erosion strength) of materials have, however, not yet been developed. In terms of modelling, speculations about the physical processes underlying water droplet erosion and consequently treating the problem from first principles have never reached a state of maturity. Efforts have, therefore, focused on formulating erosion prediction equations depending on a statistical analysis of large erosion tests data and often with a combination of presumed erosion mechanisms such as fatigue. Such prediction models have not reached the stage of generalization. Experimental testing and erosion prediction efforts need to be improved such that a coherent water droplet erosion theory can be established. The need for standardized testing and data representation practices as well as correlations between test data and real in-service erosion also remains urgent.

scholarly journals Numerical simulation of the aerobreakup of a water droplet

2017 ◽  
Vol 835 ◽  
pp. 1108-1135 ◽  
Author(s):  
Jomela C. Meng ◽  
Tim Colonius
Keyword(s):  
Numerical Simulation ◽  
Water Droplet ◽  
Gas Flow ◽  
Three Dimensional ◽  
Finite Volume Scheme ◽  
Droplet Deformation ◽  
Fourier Decomposition ◽  
Chaotic Flow ◽  
Interface Capturing ◽  
Instability Growth

We present a three-dimensional numerical simulation of the aerobreakup of a spherical water droplet in the flow behind a normal shock wave. The droplet and surrounding gas flow are simulated using the compressible multicomponent Euler equations in a finite-volume scheme with shock and interface capturing. The aerobreakup process is compared with available experimental visualizations. Features of the droplet deformation and breakup in the stripping breakup regime, as well as descriptions of the surrounding gas flow, are discussed. Analyses of observed surface instabilities and a Fourier decomposition of the flow field reveal asymmetrical azimuthal modulations and broadband instability growth that result in chaotic flow within the wake region.

scholarly journals Mechanism of Supercooled Water Droplet Breakup near the Leading Edge of an Airfoil

2017 ◽  
Author(s):  
Belen Veras-Alba ◽  
Jose Palacios ◽  
Mario M. Vargas ◽  
Charles R. Ruggeri ◽  
Tadas P. Bartkus
Keyword(s):  
Water Droplet ◽  
Leading Edge ◽  
Supercooled Water ◽  
Droplet Breakup
Sign in / Sign up

Export Citation Format

Share Document