Insight into rime ice accretion on an aircraft wing and corresponding effects on aerodynamic performance

2016 ◽  
Vol 120 (1229) ◽  
pp. 1101-1122 ◽  
Author(s):  
Y. Cao ◽  
J. Huang ◽  
Z. Xu ◽  
J. Yin
Keyword(s):  
Collection Efficiency ◽  
Control Volume ◽  
Fluid Model ◽  
Three Dimensional ◽  
Wing Surface ◽  
Ice Accretion ◽  
Governing Equations ◽  
Aircraft Wing ◽  
Two Phase ◽  
Environment Temperature

ABSTRACTA method based on the Eulerian two-phase flow theory to numerically simulate three-dimensional rime ice accretions on an aircraft wing is presented in this paper. The governing equations for supercooled droplet motion under Eulerian framework are established using the droplet pseudo-fluid model. A permeable wall boundary condition is proposed to simulate the phenomenon of droplets impinging on the wing in solving the governing equations for droplets. The local droplet collection efficiency is readily obtained from the droplet flowfield solution in the control volume adjacent to the wing surface. The rime ice accretion can be simulated under the assumption that the droplets freeze immediately as they impinge on the wing surface since the environment temperature is low enough (typically below –15°C). A method to build the ice shape is proposed based on the assumption that ice grows in the direction normal to the wing surface. The rime ice accretion on a GLC-305 swept wing model under some specific conditions has been simulated to validate the present method. Furthermore, different flight conditions, namely, different angles of attack and different angles of sideslip, have been dealt with to investigate their effects on rime ice accretion as well as the corresponding aerodynamic effects.

Simplification of Ensemble Averaged Two-Phase Flow with Heat and Mass Transfer Equations for Boiling in a Channel

2008 ◽  
Vol 273-276 ◽  
pp. 616-621
Author(s):  
Hikmet Ş. Aybar ◽  
Mohsen Sharifpur
Keyword(s):  
Two Phase Flow ◽  
Fluid Model ◽  
Three Dimensional ◽  
Phase Flow ◽  
Governing Equations ◽  
Ensemble Averaging ◽  
Two Phase ◽  
Transfer Equations ◽  
Two Fluid Model ◽  
Two Fluid

Generation of vapor and predication of its behavior is an important problem in many industries. In this study, the three dimensional governing equations for turbulence two-phase flow are derived using ensemble averaging two fluid model. The governing equations are simplified by a heuristic approach based on boiling data, and the equations are used to obtain the parameters for each phase along the channel. A computer program is written for the simplified one-dimensional equations, and the results are compared with experimental data.

Numerical simulation of rime ice accretions on an aerofoil using an Eulerian method

2008 ◽  
Vol 112 (1131) ◽  
pp. 243-249 ◽  
Author(s):  
Y. Cao ◽  
Q. Zhang ◽  
J. Sheridan
Keyword(s):  
Collection Efficiency ◽  
Pressure Coefficient ◽  
Phase Flow ◽  
Layer By Layer ◽  
Ice Accretion ◽  
Governing Equations ◽  
Two Phase ◽  
Eulerian Method ◽  
Ice Accretions ◽  
Collocated Grid

Abstract Based on two-phase flow theory, an Eulerian method to simulate rime ice accretions on an aerofoil has been developed. The SIMPLE (semi-implicit method for pressure linked equations) algorithm on a collocated grid is employed to solve the governing equations for the airflow. In order to simulate droplets impinging on an aerofoil, a permeable wall is proposed to solve the governing equations for supercooled droplets. The collection efficiency and impingement limits are obtained from the droplets’ flowfield. The process of ice accretion is simulated using the assumption that ice accumulates layer-by-layer and the ice shape is predicted with the assumption that ice grows in the direction normal to the aerofoil surface. The rime ice accretions on a NACA0012 aerofoil at 0° and 4° angles-of-attack have been investigated and there is agreement between the simulated results and previously published experimental data. The change of the pressure coefficient along the iced aerofoil is also analysed.

Cavitating Flow Simulation in a Closed Pump Sump by Two-Fluid Model and Its PIV Verification

2003 ◽  
Author(s):  
Yu Xu ◽  
Yulin Wu ◽  
Shuhong Liu ◽  
Yong Li
Keyword(s):  
Fluid Model ◽  
Flow Simulation ◽  
Cavitating Flow ◽  
Governing Equations ◽  
Two Phase ◽  
Averaged Equations ◽  
Flow Through ◽  
Pump Sump ◽  
Two Fluid Model ◽  
Two Fluid

In this paper, the two-fluid model was adopted to analyze the cavitating flow. Based on Boltzmann equation, governing equations for two-phase cavitating flow were obtained by using the microscopic kinetic theory, in which the equation terms for mass and momentum transportations can be obtained directly. Then the RNG k–ε–kg turbulence model, that is RNG k–ε model for the liquid phase and kg model for the cavity phase, was used to close the Reynolds time-averaged equations. According to the governing equations above, the simulation of the two-phase cavitating flow through a closed pump sump has been carried out. The calculated results have been compared with a PIV experiment. Good agreement exhibited.

Verification of STACS-VOF Based Two-Phase Flow Model for Interfacial Flows

2012 ◽  
Vol 212-213 ◽  
pp. 1098-1102
Author(s):  
Bin Deng ◽  
Chang Bo Jiang ◽  
Zhi Xin Guan ◽  
Chao Shen
Keyword(s):  
Flow Model ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Test Cases ◽  
Phase Flow ◽  
Interfacial Flows ◽  
Governing Equations ◽  
Two Phase ◽  
Resolution Scheme ◽  
Volume Method

The numerical calculation and simulation of gas-liquid two-phase flows with interfacial deformations have nowadays become more and more popular issues in various scientific and industrial fields. In this study, a three-dimensional gas-liquid two-phase flow numerical model is presented for investigating interfacial flows. The finite volume method was used to discretize the governing equations. A High-resolution scheme of VOF method (STACS) is applied to capture the free surface. The paper outlines the methodology of STACS and its validation against three typical test cases used to verify its accuracy. The results show the STACS-VOF gives very satisfactory results for three-dimensional two-phase interfacial flows problem, and this scheme performs more accurate and less diffusive preserving interface sharpness and boundedness.

Prediction of Ice Accretion on Wind Turbine with Numerical Method

2012 ◽  
Vol 512-515 ◽  
pp. 754-757
Author(s):  
Xian Yi ◽  
Kai Chun Wang ◽  
Hong Lin Ma
Keyword(s):  
Wind Turbine ◽  
Numerical Method ◽  
Collection Efficiency ◽  
Three Dimensional ◽  
Horizontal Axis ◽  
Ice Accretion ◽  
Horizontal Axis Wind Turbine ◽  
Blade Tip ◽  
Computer Codes ◽  
Multiple Reference

A three dimensional numerical method and its computer codes, which are suitable to predict the process of horizontal axis wind turbine icing, are presented. The method is composed of the Multiple Reference Frame (MRF) method to calculate flowfield of air, an Eulerian method to compute collection efficiency and a three dimensional icing model companying with an iterative arithmetic for solving the model. Ice accretion on a 1.5 MW horizontal axis wind turbine is then computed with the numerical method, and characteristics of droplet collection efficiency and ice shape/type are obtained. The results show that ice on the hub and blade root is slight and it can be neglected comparing with ice near blade tip. From blade tip to root, ice becomes thinner and glaze ice may changes into rime ice.

A Numerical Study of Droplet Impingement for In-Flight Ice Accretion Prediction

2016 ◽  
Author(s):  
Hao Zhang ◽  
Chihyung Wen ◽  
Junwei Su
Keyword(s):  
Collection Efficiency ◽  
Numerical Study ◽  
Three Dimensional ◽  
Ice Accretion ◽  
Eulerian Model ◽  
Droplet Impingement ◽  
Basic Module ◽  
Wide Range ◽  
Subsonic Regime ◽  
Finite Volume Approach

Droplet impingement is the basic module in both ice accretion and anti-icing numerical calculation. A three dimensional finite volume approach with the capacity of modeling the in-flight droplet impingement on a wide range of subsonic regime is therefore established in this research, using OpenFOAM®. The Eulerian model is applied to estimate the droplet flow field with the same computational grid sets as those of the air flow calculation. The roughness effect caused by ice accretion is considered in the wall function modeling. Thus, the collection efficiency could be investigated for further icing numerical simulations. This approach is validated on both cylinder and sphere benchmark cases. The results are compared with the corresponding experimental and LEWICE (LEWis ICE accretion program) simulation data.

A mixed finite element/control volume model of wind-driven circulation in lakes

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Victor Podsechin
Keyword(s):  
Control Volume ◽  
Mixed Finite Element ◽  
Surface Wind ◽  
Three Dimensional ◽  
Circulation Model ◽  
Hydrodynamic Equations ◽  
Governing Equations ◽  
Near Surface ◽  
Stream Functions ◽  
Surface Wind Field

AbstractA three-dimensional numerical circulation model is described. The model is based on non-linear hydrodynamic equations, modified according to hydrostatic and Boussinesq approximations. A space-splitting scheme is used for numerical approximations of governing equations. The simple hypothesis on elliptic stream functions shape is utilized to reconstruct the near-surface wind field. The calculated currents correspond reasonably well with observed velocities in different locations lake-wide.

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