Airfoils Aerodynamic Performance Analysis in Heavy Rain

2012 ◽  
Vol 245 ◽  
pp. 297-302
Author(s):  
Muhammad Ismail ◽  
Yi Hua Cao
Keyword(s):  
Airline Industry ◽  
Heavy Rain ◽  
Quantitative Information ◽  
Aerodynamic Performance ◽  
Small Scale ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Aerodynamic Efficiency ◽  
Discrete Phase ◽  
Cfd Method

Heavy rainfall greatly affects the aerodynamic performance of the aircraft. There are many accidents of aircraft caused by aerodynamic efficiency degradation due to heavy rain. In this paper we have studied the heavy rain effects on the aerodynamic efficiency of NACA 64210 and NACA 0012 airfoils with cruise and landing configuration. For our analysis, CFD method and preprocessing grid generator are used as our main analytical tools, and the simulation of rain is accomplished via two phase flow approach named as Discrete Phase Model (DPM). Raindrops are assumed to be non-interacting, non-deforming, non evaporating and non spinning spheres. Both cruise and landing configurations of airfoils exhibited significant reduction in lift and increase in drag for a given lift condition in simulated rain. Our results are in good agreement with the experimental results. It is expected that the quantitative information gained in this paper will be useful to the operational airline industry and greater effort such as small scale and full scale flight tests should put in this direction to further improve aviation safety.

Aerodynamic Performance Investigation under the Influence of Heavy Rain of a NACA 0012 Airfoil for Wind Turbine Applications

2012 ◽  
Vol 6 (6) ◽  
pp. 1228-1235
Author(s):  
Eleni C. Douvi ◽  
Dionissios P. Margaris
Keyword(s):  
Flow Field ◽  
Wind Turbine ◽  
Heavy Rain ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Spherical Particles ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Naca0012 Airfoil ◽  
The Impact

The study of the prediction of the flow field and aerodynamic characteristics of a NACA0012 airfoil in simulated heavy rain, using a computational fluid dynamics code is presented. The simulation of rain is accomplished by using the two-phase flow Discrete Phase Model, which is available in the CFD code. Spherical particles are tracked through the two-dimensional, incompressible air flow field over a NACA0012 airfoil, at a simulated rain rate of 1000 mm/h and operating at Reynolds numbers Re=1×106 and Re=3×106. To validate the CFD developed model, the results are compared with well-established and published experimental data, showing good agreement. The aim of the work was to show the behavior of the airfoil at these conditions and to establish a verified solution method. Lift and drag coefficients are computed at various angles of attack in both dry and wet conditions and the results are compared to show the effects of rain at airfoil performance. The impact of rain on wind turbine performance is also analyzed. It is concluded that rain causes degradation of aerodynamic performance, especially lift is decreased and drag is increased.

Aerodynamic Characteristics of NACA 23015 Landing Configuration with 20o Flap in Simulated Rain

2014 ◽  
Vol 555 ◽  
pp. 108-112
Author(s):  
Shahid Latif ◽  
Zhou Hong ◽  
Muhammad Ismail
Keyword(s):  
Heavy Rain ◽  
Aerodynamic Characteristics ◽  
Continuous Phase ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase Modeling ◽  
Wall Film ◽  
Discrete Phase ◽  
Simulated Rain

In our numerical simulation the heavy rain effects have been studied on the aerodynamic performance of 2D cambered NACA 23015 airfoil landing configuration with 20o. We have used preprocessing software gridgen for creation of the landing configuration of the airfoil and then creating mesh around it. Fluent is used to solve the conservation equations. We have used discrete phase modeling (DPM) in Fluent to simulate the rain phenomenon in continuous phase flow by using two phase flow approach. In our study the coupling between the discrete and the continuous phase has been activated. In discrete phase model (DPM), we used the wall film model for the interaction of the continuous and discrete phase. The airfoil landing configuration exhibited significant decrease in lift and increase in drag for a given lift conditions in simulated rain. Post processing software like MATLAB, Tec plot and Origin are used to see the effects of the heavy rain and then results obtained are compared with the experimental results. Our numerical results in most of cases show similar trends with the experiments.

Numerical simulation of raindrops distribution on canopy surface of hemispherical parachute in heavy rain via two-phase flow approach

2016 ◽  
Vol 231 (4) ◽  
pp. 657-668 ◽  
Author(s):  
Jian Yue ◽  
Puyun Gao ◽  
Mingliang Zhang ◽  
Wenke Cheng
Keyword(s):  
Numerical Simulation ◽  
Two Phase Flow ◽  
Heavy Rain ◽  
Critical Value ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase ◽  
Simulation Results ◽  
High Pressure Zone

The descent of parachute and re-entry capsule in heavy rain has been rarely researched yet. Study of raindrops distribution on canopy surface in heavy rain environment is a key step in the whole research. In this paper, the discrete phase model of two-phase flow approach is applied to simulate the raindrop trajectories in order to research the problem of raindrops distribution on canopy surface when parachute and re-entry capsule are descending in heavy rain. Numerous cases based on different rainfall rates and vertically descending velocities of a simple hemispherical parachute and re-entry capsule are numerically calculated preliminarily. The simulation results are presented, and it is found that the raindrops trapped by the canopy surface are not even-distributed, and raindrops are concentrated near the bottom edges of canopy surface as a result of high-pressure zone enclosed by the parachute; there is a corresponding critical value of descending velocity of parachute and re-entry capsule which determines whether the raindrops will be trapped by the canopy surface for one particular rainfall rate; only above the critical value of descending velocity of parachute and re-entry capsule the raindrops can be trapped by the canopy surface. The conclusions will be of great significance to the further research of the problem of descent of parachute and re-entry capsule in heavy rain.

Numerical Simulation of Two-Phase Flow inside and outside a Swirl Nozzle for Dispersing Superfine Powder

2012 ◽  
Vol 505 ◽  
pp. 170-174
Author(s):  
Wei Dong Shi ◽  
Liang Zhang ◽  
Hai Yan He ◽  
Jiang Hai Liu ◽  
Liang Chen
Keyword(s):  
Total Pressure ◽  
Concentration Distribution ◽  
Gas Flow ◽  
Reynolds Stress Model ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase ◽  
Particle Group ◽  
Nozzle Structure

In this paper, a swirl nozzle is established to disperse superfine powder aerodynamically. And Reynolds stress model (RSM) is adopted to simulate the strongly swirling, compressible and transonic gas flow in the nozzle and its rear. Combined with discrete phase model (DPM), the concentration distribution of particle group in size of 2.5μm is studied. The simulated results show that, the distribution of swirl strength is determined basically by the nozzle structure, while the total pressure has little effect on it; compared with an irrotational nozzle, the swirl nozzle could achieve a better dispersing effect for superfine powder.

scholarly journals Prediction of Horizontal Pneumatic Conveying of Large Coal Particles Using Discrete Phase Model

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Daolong Yang ◽  
Ge Li ◽  
Yanxiang Wang ◽  
Qingkai Wang ◽  
Jianping Li ◽  
...  
Keyword(s):  
Simulation Method ◽  
Phase Model ◽  
Pneumatic Conveying ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Coal Particles ◽  
Large Particles ◽  
Discrete Phase ◽  
Field Velocity ◽  
Conveying System

The pneumatic conveying focusing on gas-solid two-phase flow plays an important role in a conveying system. Previous work has been conducted in the fields of small particles, where the size was less than 5 mm; however, there are few studies regarding large sizes (>5 mm). In order to predict the horizontal pneumatic conveying of large coal particles, the coupling methods based on the Euler–Lagrange approach and discrete phase model (DPM) have been used for the simulated research. Compared with the experimental results under the same working condition, the particle trajectory obtained by simulation is similar to the particle distribution at the same position in the experiment, and it turns out that the simulation method is feasible for the horizontal pneumatic conveying of large particles. Multifactor simulations are also carried out to analyse the effects of particle size, flow field velocity, solid-gas rate, and pipe diameter on the wall abrasion during horizontal pneumatic conveying, which provides simulation reference and design guide for pneumatic conveying of large particles.

Study of the Effects of Shearer’ Kinematic Parameters on on-Way Distribution of Dust on Coal Face

2011 ◽  
Vol 127 ◽  
pp. 400-405
Author(s):  
Xiao Huo Li ◽  
Shu Ming Liu ◽  
Zhi Long Huang ◽  
Wei Du
Keyword(s):  
Rotational Speed ◽  
Dust Concentration ◽  
Discrete Phase Model ◽  
Kinematic Parameters ◽  
Coal Face ◽  
Two Phase ◽  
Concentration Maximum ◽  
Discrete Phase ◽  
And Migration ◽  
Kinematical Parameters

In order to research the effects of shearer’ kinematical parameters on on-way distribution of dust on coal face, according to the theory of suspension gas-solid two-phase flow and the theory of cutting dust formation, mathematical model of on-way dust concentration was established, methods of determining parameters were given, dust migration was simulated by using the discrete phase model (DPM) in FLUENT, on-way distribution regularity of dust was found. According to calculation of the quantity of cutting dust at different hauling speed and different rotational speed of drum, dust migration was simulated and migration regularity was showed as follows: dust concentration of every point on a coal face increased as hauling speed decreased or rotational speed increased. In addition, with rotational speed increased, the position of concentration maximum moved a little along downwind.

Numerical Simulation of Flow Field in a Quench Oil Tower

2007 ◽  
Author(s):  
Shuihua Zheng ◽  
Shengchang Zhang ◽  
Zengliang Gao
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Flow Field ◽  
Petrochemical Industry ◽  
Flow Distribution ◽  
Discrete Phase Model ◽  
Wide Range ◽  
Modification Method ◽  
Discrete Phase ◽  
Cfd Method

Towers are applied in the wide range of the petrochemical industry. The flow condition and the temperature distribution in the tower are the focus of the people’s attention, which would affect function of the tower and could result in unstable operation of the tower. In this paper, the flow field in a quench oil tower is simulated based on CFD method. The DPM (Discrete Phase Model) is used to calculate and analyze flow distribution and heat transfer between gas and liquid. The numerical results such as temperature and velocity distributions below lower tray in tower are obtained. According to CFD results, modification method of improving the flow distribution is proposed.

Effect of particle mass concentration on erosion characteristics of self-priming pump

2021 ◽  
pp. 095440622110007
Author(s):  
Wenqi Zhang ◽  
Shuai Yang ◽  
Dazhuan Wu ◽  
Jiegang Mou
Keyword(s):  
Structural Damage ◽  
Leading Edge ◽  
Discrete Phase Model ◽  
Suction Surface ◽  
Two Phase ◽  
Lower Velocity ◽  
Damage And Failure ◽  
Discrete Phase ◽  
Flow Medium ◽  
Solid Liquid

The self-priming pump is widely used in conveying the solid-liquid two-phase flow medium. The particles in the medium erode the components, leading to structural damage and failure. The computational fluid dynamics (CFD) model of the 65ZW30-20 self-priming pump is built to study erosion characteristics and mechanisms. FLUENT, along with the Discrete Phase Model and Oka erosion model, is applied for the numerical simulation. The particle distribution, impact times and velocity, and trajectories are taken into consideration to investigate the erosion characteristics in each component. The results show that with the increase of the particle concentration, the head and efficiency decreases gradually. The volute wall and blade leading edge are the most vulnerable regions to erosion, because of a large number of impact times and high impact velocity. Also, the particles impact the front gap wall for fewer times and the hub with lower velocity, which leads to a slighter erosion. Besides, the particle trajectories indicate that some particles impact the blade suction surface and the paraxial area of the shroud, rendering considerable erosion.

scholarly journals The Operation of a Three-Bladed Horizontal Axis Wind Turbine under Hailstorm Conditions—A Computational Study Focused on Aerodynamic Performance

Inventions ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 2
Author(s):  
Dimitra Douvi ◽  
Eleni Douvi ◽  
Dionissios P. Margaris
Keyword(s):  
Wind Turbine ◽  
Cross Sections ◽  
Computational Study ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Horizontal Axis ◽  
Discrete Phase Model ◽  
Horizontal Axis Wind Turbine ◽  
Ansys Fluent ◽  
Discrete Phase

The aim of this study is the aerodynamic degradation of a three-bladed Horizontal Axis Wind Turbine (HAWT) under the influence of a hailstorm. The importance and originality of this study are that it explores the aerodynamic performance of an optimum wind turbine blade during a hailstorm, when hailstones and raindrops are present. The commercial Computational Fluid Dynamics (CFD) code ANSYS Fluent 16.0 was utilized for the simulation. The first step was the calculation of the optimum blade geometry characteristics for a three-bladed rotor, i.e., twist and chord length along the blade, by a user-friendly application. Afterwards, the three-dimensional blade and the flow field domain were designed and meshed appropriately. The rotary motion of the blades was accomplished by the application of the Moving Reference Frame Model and the simulation of hailstorm conditions by the Discrete Phase Model. The SST k–ω turbulence model was also added. The produced power of the wind turbine, operating in various environmental conditions, was estimated and discussed. Contours of pressure, hailstone and raindrop concentration and erosion rate, on both sides of the blade, are presented. Moreover, contours of velocity at various cross sections parallel to the rotor are demonstrated, to understand the effect of hailstorms on the wake behavior. The results suggest that the aerodynamic performance of a HAWT degrades due to impact and breakup of the particles on the blade.

Simulation of an Aero-Engine Bearing Compartment Using Two-Way Transition Between Lagrangian Droplets and a Three-Dimensional Eulerian Liquid Film

2019 ◽  
Author(s):  
Jean-Sebastien Dick ◽  
Vivek Kumar ◽  
Pravin Nakod ◽  
Federico Montanari
Keyword(s):  
Liquid Film ◽  
Fluid Model ◽  
Three Dimensional ◽  
Mesh Size ◽  
Liquid Structure ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Aero Engine ◽  
Discrete Phase ◽  
Modeling Strategy

Abstract This paper presents a new hybrid two-phase flow numerical model. It uses the Discrete Phase Model (DPM) and the Volume of Fluid model (VoF) to study the interaction between air, oil droplets and films in a bearing compartment. It allows transition from a trackable Lagrangian particle, such as a droplet, into a continuous liquid structure in a Eulerian frame of reference. The transition can also be performed in the opposite direction, where a continuous liquid structure can be converted back into a trackable particle if specific requirements are met. The method is designated as DPM-VoF-DPM throughout this paper. Test cases capturing the impingement of a droplet in a liquid film are performed to assess its effectiveness. The simulation of a simplified bearing compartment is compared with measurements and results obtained using a standard VoF modeling approach. Mechanisms which are usually modeled such as droplet splashing, film separation, and droplet stripping, can now be physically captured with reduced computing resources by allowing transition from continuous liquid structures to discrete parcels. The employed modeling strategy allows for high resolution of the oil film at the walls and tracking of the droplets while minimizing mesh size and computing needs. Current results suggest that the proposed DPM-VoF-DPM method can be an efficient and accurate tool for locating air and oil in aero-engine transmission systems.

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