scholarly journals Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Force ◽  
Rotor Blade ◽  
Flow Direction ◽  
Three Dimensional ◽  
Simulation Method ◽  
Two Phase ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Flow Field Characteristics

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.

The Research on Steering Fracture Numerical Simulation

2013 ◽  
Vol 734-737 ◽  
pp. 1488-1492
Author(s):  
Zhen Yu Liu ◽  
Li Hong Yao ◽  
Hu Zhen Wang ◽  
Cui Cui Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Simulation Method ◽  
Production Performance ◽  
Phase Flow ◽  
Water Production ◽  
Two Phase ◽  
Fractured Well

The fractures after artificial steering fracturing appear in shades of curved surface. Aiming at the problem of steering fracture, in the paper, numerical simulation method under the condition of three-dimensional two-phase flow is presented based on finite element method. In this method, of steering fracture was achieved by adopting surface elements fractures and tetrahedron elements to describe formation. By numerical simulation, the change rule of oil and water production performance of steering fractures can be calculated, and then the steering fracture parameters can be optimized before fracturing. A new method was supplied for the numerical simulation of artificial fractured well.

Three-Dimensional Numerical Simulation of the Flow around Two Side-by-Side Cylinders of Different Diameters

2014 ◽  
Vol 721 ◽  
pp. 199-202
Author(s):  
Zhen Xiao Bi ◽  
Zhi Han Zhu
Keyword(s):  
Numerical Simulation ◽  
Flow Direction ◽  
Three Dimensional ◽  
Cross Flow ◽  
Simulation Method ◽  
Scale Model ◽  
Hydrodynamic Characteristics ◽  
Eddy Simulation ◽  
Drag And Lift ◽  
Different Diameters

This paper presents the calculation of hydrodynamic characteristics of two side-by-side cylinders of different diameters in three dimensional incompressible uniform cross flow by using Large-eddy simulation method based on dynamical Smagorinsky-Lilly sub-grid scale model. Solution of the three dimensional N-S equations were obtained by the finite volume method. The numerical simulation focused on investigating the characteristic of the pressure distribution (drag and lift force), vorticity field and turbulence Re=. Results shows that, the asymmetry of the time –averaged velocity distribution in the flow direction behind the two cylinders is very obvious; the frequency of eddy shedding of the small cylinder is about twice of the large one. The turbulence of cylinders is more obvious.

626 Development of Numerical Simulation Method of Dispersed Two-Phase Flow Using a Euler-Lagrange Model

2000 ◽  
Vol 2000.75 (0) ◽  
pp. _6-51_-_6-52_
Author(s):  
Koji ARAKI ◽  
Katsuteru HASHIMOTO ◽  
Tomio OKAWA ◽  
Kenji YOSHIDA ◽  
Tadayoshi MATSUMOTO ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Two Phase Flow ◽  
Simulation Method ◽  
Phase Flow ◽  
Two Phase ◽  
Numerical Simulation Method

scholarly journals Study on the Thermal Environment Inside a Fully-Enclosed Subway Noise Barrier

2020 ◽  
Vol 143 ◽  
pp. 01044
Author(s):  
Lei Liu ◽  
Lianghan Zhang ◽  
Zhongxu Kang ◽  
Kun Yao
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Air Temperature ◽  
Thermal Environment ◽  
Simulation Method ◽  
Internal Environment ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Noise Barrier ◽  
Air Vent

The thermal environment inside a fully-enclosed subway noise barrier shall be designed according to underground section tunnel standards. This article constructs a model using practical examples, simulates calculations on fully-enclosed noise barrier installations both with and without air vents via a threedimensional numerical simulation method, and then conducts a comparative analysis of the effects noise barrier lengths and air vent widths have on an internal thermal environment. The calculation results show that when the length of the fully-enclosed noise barrier without air vents was 100m, the internal thermal environment exceeded the limit; as the width of the air vents increased, the temperature in the internal environment gradually decreased, but the reduction was less once the air vent width exceeded 2 m; When the top air vent width was 2 m, and the noise barrier length was 100m, the thermal environment was found to meet requirements. As the noise barrier length increased, the internal air temperature exceeded the standards by varying degrees.

Numerical simulation of three-dimensional rotor icing in hovering flight

2016 ◽  
Vol 232 (3) ◽  
pp. 545-555 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Force ◽  
Liquid Water ◽  
Water Distribution ◽  
Three Dimensional ◽  
Leading Edge ◽  
Hovering Flight ◽  
Two Phase ◽  
Distribution Method ◽  
Overlapping Grids

Rotor icing is a serious threat to helicopter flight safety and computational fluid dynamics technology is very useful in icing prediction. In this work, a numerical simulation method is presented to calculate three-dimensional rotor icing in hovering flight. The rotor flow fields are obtained using overlapping grids. According to Euler two-phase flow, the droplet trajectories and impingement characteristics are predicted. On the basis of three-dimensional ice accretion model, a new runback water distribution method based on shear force and centrifugal force is proposed to simulate liquid water flow and ice shape. The calculation results are compared with the experimental results under different conditions in order to verify the correctness of the method. Furthermore, the effects of blades rotation on the liquid water content distribution and droplet impingement characteristics are studied, and the effect of centrifugal force on ice shape is analyzed. The results show that the blade will influence others with the blade tip Mach number increasing, and centrifugal force will cause the ice thickness increases on leading edge and decreases at both frozen limitations.

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