scholarly journals Numerical Simulation of the Effect of Different Number Leading Edge Winglets on the Fan-Wing Aerodynamic Characteristics

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Du Siliang ◽  
Zhao Qijun ◽  
Tang Zhengfei
Keyword(s):  
Numerical Simulation ◽  
Engineering Application ◽  
Leading Edge ◽  
Low Pressure ◽  
Aerodynamic Characteristics ◽  
Opening Angle ◽  
Coupling Relationship ◽  
Aerodynamic Moment ◽  
And Control ◽  
Wing Airfoil

The generation of lift and thrust mainly depends on the formation of low-pressure vortices above the arc groove on the leading edge of the Fan-wing, which makes the lift and thrust have a strong coupling relationship. How to decouple and control the lift and thrust is the key to further engineering application of the Fan-wing. Normally, the geometric parameters of the Fan-wing airfoil were determined; the leading edge opening angle has the greatest influence on the aerodynamic performance. Therefore, the method of installing leading edge winglets on the leading edge of a base Fan-wing airfoil was considered to change the opening angle of the leading edge of the Fan-wing. Through numerical simulation, the effects of single, double, and triple leading edge winglets on lift and thrust of the Fan-wing at different installation angles, inflow velocities, and angles of attack were compared and analyzed. The results show that by controlling the angle of the leading edge winglet, not only the lift and thrust of the fan can be improved but also the strength and position of the low-pressure vortices can be controlled, so as to meet the active control requirements of the aerodynamic moment of the Fan-wing, and then the attitude of the Fan-wing aircraft can be controlled.

Design of Two Counter-Rotating Fan Types and CFD Investigation of Their Aerodynamic Characteristics

2011 ◽  
Author(s):  
Xiao-He Yang ◽  
Peng Shan
Keyword(s):  
Pressure Ratio ◽  
Leading Edge ◽  
Low Pressure ◽  
Aerodynamic Characteristics ◽  
Civil Aviation ◽  
Speed Ratio ◽  
Rotating Speed ◽  
High Pressure Ratio ◽  
The Military ◽  
Bypass Ratio

The design information and numerical investigation are presented for two kinds of counter-rotating fans. The fans, both vaneless and non-aspirated, are intended for a civil aviation engine with a bypass ratio of 8 and for a military engine with a bypass ratio of 0.5 respectively. The pressure ratios are respectively 1.60 and 3.50, and the tip speeds are (300 m/s, −222 m/s) and (500 m/s, −391 m/s). The design rotating speed ratio of the front to the aft rotor is discussed based on one-dimensional analysis. The variations in pressure ratios, isentropic efficiencies, diffusion losses and shock losses at mean-line with the design rotating speed ratios are studied. The flow fields of the two contra-stages are numerically simulated and the detailed flow physics is investigated at both design and off-design conditions. The simulations reveal that the two stages both perform well. The civil engine contra-stage test fans are still conventional transonic rotors due to the low pressure ratio and low tip speeds. For the military engine contra-stage, the aft rotor differs from the conventional transonic front rotor. It is a full-span relative supersonic rotor in which both the leading edge shock and the passage shock extend from the casing to the hub. At the stall point, for the low pressure ratio civil test fan, both the front and aft rotors are stalled and the shocks detached. In the corresponding high pressure ratio military fan, only the aft rotor is stalled which determines the stage stall point.

scholarly journals Numerical study of the aerodynamic characteristics of a triangular wing at different angles of attack and large Mach numbers

2021 ◽  
pp. 1-24
Author(s):  
Ivan Anatolievich Shirokov
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Study ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Coefficients ◽  
Gas Dynamic ◽  
Triangular Wing ◽  
Mach Numbers ◽  
Good Agreement

The results of numerical simulation of the external supersonic flow around a triangular wing with a blunted leading edge at Mach numbers 6 and 9, obtained in the framework of a quasi-gas dynamic (QGD) algorithm, are presented. The formulation of the problem at Mach number 9 corresponds to experiments in a wind tunnel. The values of the aerodynamic coefficients obtained at different angles of attack are in good agreement with the experimental data. It is shown that the modeling carried out using more detailed grids is more accurate.

The Leading-edge and Unique Technology,Mitsubishi Low Pressure EGR

2017 ◽  
Vol 04 (03) ◽  
pp. 215-223
Author(s):  
Takashi Ueda ◽  
Kazuhisa Ito ◽  
Naohiro Hiraoka
Keyword(s):  
Leading Edge ◽  
Low Pressure

scholarly journals Numerical Simulation and Engineering Application of Coalbed Water Injection

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yijie Shi ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Xuanhao Tan ◽  
Wen Zhang
Keyword(s):  
Numerical Simulation ◽  
Process Parameters ◽  
Water Injection ◽  
Engineering Application ◽  
Working Environment ◽  
Engineering Practice ◽  
Characteristic Parameters ◽  
Injection Process ◽  
Working Face ◽  
Dust Reduction

Coalbed water injection is the most basic and effective dust-proof technology in the coal mining face. To understand the influence of coalbed water injection process parameters and coalbed characteristic parameters on coal wetting radius, this paper uses Fluent computational fluid dynamics software to systematically study the seepage process of coalbed water injection under different process parameters and coalbed characteristic parameters, calculation results of which are applied to engineering practice. The results show that the numerical simulation can help to predict the wetness range of coalbed water injection, and the results can provide guidance for the onsite design of coalbed water injection process parameters. The effect of dust reduction applied to onsite coalbed water injection is significant, with the average dust reduction rates during coal cutting and support moving being 67.85% and 46.07%, respectively, which effectively reduces the dust concentration on the working face and improves the working environment.

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

Unsteady Numerical Simulation of Shock Systems in Vaneless Counter-Rotating Turbine

2005 ◽  
Author(s):  
Huishe Wang ◽  
Qingjun Zhao ◽  
Xiaolu Zhao ◽  
Jianzhong Xu
Keyword(s):  
Numerical Simulation ◽  
Mach Number ◽  
Leading Edge ◽  
Turbine Rotor ◽  
Nozzle Design ◽  
Suction Surface ◽  
Rotor Wake ◽  
Wake Interaction ◽  
Unsteady Numerical Simulation ◽  
Almost All

A detailed unsteady numerical simulation has been carried out to investigate the shock systems in the high pressure (HP) turbine rotor and unsteady shock-wake interaction between coupled blade rows in a 1+1/2 counter-rotating turbine (VCRT). For the VCRT HP rotor, due to the convergent-divergent nozzle design, along almost all the span, fishtail shock systems appear after the trailing edge, where the pitch averaged relative Mach number is exceeding the value of 1.4 and up to 1.5 approximately (except the both endwalls). A group of pressure waves create from the suction surface after about 60% axial chord in the VCRT HP rotor, and those waves interact with the inner-extending shock (IES). IES first impinges on the next HP rotor suction surface and its echo wave is strong enough and cannot be neglected, then the echo wave interacts with the HP rotor wake. Strongly influenced by the HP rotor wake and LP rotor, the HP rotor outer-extending shock (OES) varies periodically when moving from one LP rotor leading edge to the next. In VCRT, the relative Mach numbers in front of IES and OES are not equal, and in front of IES, the maximum relative Mach number is more than 2.0, but in front of OES, the maximum relative Mach number is less than 1.9. Moreover, behind IES and OES, the flow is supersonic. Though the shocks are intensified in VCRT, the loss resulted in by the shocks is acceptable, and the HP rotor using convergent-divergent nozzle design can obtain major benefits.

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

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