Hydromechanics Analysis with Flow-Field Characteristics of High Pressure Water-Jet in Sloping Bottom Hole of Radial Horizontal Drilling

2014 ◽  
Vol 952 ◽  
pp. 190-193
Author(s):  
Xian Zhong Yi ◽  
Song Lin Yi ◽  
Hui Shu ◽  
Yuan Qiang Ji ◽  
Sheng Zong Jiang
Keyword(s):  
Flow Field ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Horizontal Drilling ◽  
Bottom Hole ◽  
Flow Field Characteristics ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Radial Drilling ◽  
The Impact

According to the principle of fluid dynamics, the Fluent software is used for the numerical simulation analysis of three-dimensional single-hole nozzle submerged jet flow field of radial drilling inclined shaft. The results show that when the bottom is tilted, there are two sizes of spiral along the center axis, and the vortices along tilt direction of the wall are stronger. When the jet source closes the bottom, the kinetic energy of jet is converted into the impact for the bottom of well, making the pressure of bottom hole on the wall have a tendency to rise.

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

Numerical study of the impact of water injection holes arrangement on cavitation flow control

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987774 ◽  
Author(s):  
Wei Wang ◽  
Qingdian Zhang ◽  
Tao Tang ◽  
Shengpeng Lu ◽  
Qi Yi ◽  
...  
Keyword(s):  
Flow Field ◽  
Numerical Study ◽  
Water Injection ◽  
Three Dimensional ◽  
Hydrodynamic Performance ◽  
Cavitation Flow ◽  
Suction Surface ◽  
Double Row ◽  
Suppression Effect ◽  
The Impact

A method of water injection to flow field using distributed holes on the suction surface of hydrofoil is presented in this article to control cavitation flow. Modified renormalization group k–ε turbulence model is coupled with full-cavitation model to calculate periodical cavitation patterns and the dynamic characteristics of the NACA66(MOD) hydrofoil. Water injection is found to be highly effective for cavitation suppression. The cavitation suppression effect of distributed regulation of jet holes and porosities along three-dimensional spanwise hydrofoil is also investigated. The appropriate porosities of single row spanwise jet holes and optimal jet position of double row jet holes are revealed for both cavitation suppression and good hydrodynamic performance. Double row jet holes setting in forward trapezoidal arrangement shows great potential for cavitation suppression and hydrodynamic performance. This research provides a method of water injection to flow field to actively control cavitation, which will facilitate development of engineering designs.

Numerical Simulation and Experimental Verification of the Deposition Concentration of an Unmanned Aerial Vehicle

2019 ◽  
Vol 35 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Qiang Shi ◽  
Hanping Mao ◽  
Xianping Guan
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Unmanned Aerial Vehicle ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Utilization Rate ◽  
Droplet Deposition ◽  
Aerial Vehicle ◽  
Motion Characteristics

Abstract. To analyze the droplet deposition under the influence of the flow field of an unmanned aerial vehicle (UAV), a hand-held three-dimensional (3D) laser scanner was used to scan 3D images of the UAV. Fluent software was used to simulate the motion characteristics of droplets and flow fields under the conditions of a flight speed of 3 m/s and an altitude of 1.5 m. The results indicated that the ground deposition concentration in the nonrotor flow field was high, the spray field width was 2.6 m, and the droplet deposition concentration was 50 to 200 ug/cm2. Under the influence of the rotor flow field, the widest deposition range of droplets reached 12.8 m. Notably, the droplet deposition uniformity worsened, and the concentration range of the droplet deposition was 0 to 500 ug/cm2. With the downward development of the downwash flow field, the overall velocity of the flow field gradually decreased, and the influence interval of the flow field gradually expanded. In this article, the droplet concentration was verified under simulated working conditions by a field experiment, thereby demonstrating the reliability of the numerical simulation results. This research could provide a basis for determining optimal UAV operating parameters, reducing the drift of droplets and increasing the utilization rate of pesticides. Keywords: Unmanned aerial vehicle (UAV), Aerial application, Downwash flow field, Droplet deposition, Simulation analysis.

Numerical Investigation of Positive Displacement Rotary Lobe Pump With Twisted Rotors

2014 ◽  
Author(s):  
Xiaojun Jiang ◽  
Yi Li ◽  
Zhaohui He ◽  
Cui Baoling ◽  
Wenlong Dong
Keyword(s):  
Flow Structure ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Dynamic Flow ◽  
Flow Fluctuation ◽  
Flow Field Characteristics ◽  
Lobe Pump ◽  
The Impact

The three-dimensional flow field characteristics are obtained by performing numerical simulation of flow in a lobe pump with twisted rotors. The relationship between the dynamic flow structure and the flow fluctuation is explored. Actually, the viscous incompressible Navier-Stokes equations are solved within an unsteady flow model. The dynamic mesh technique is applied to obtain the dynamic flow structure. By comparing the simulated results of straight rotor with those of twisted rotor, the effect of rotor shape on the flow fluctuation was revealed. Finally, the impact of the lobes number of rotors on flow pulsations is discussed. The results show that there is an intrinsic relationship between the flow fluctuation and the vortex in the lobe pump. The use of twisted rotors can effectively improve the internal flow characteristics of lobe pump and reduce flow fluctuation. With the increase of the number of lobes, the lobe pump output is more stable and capacity has been improved.

The effect analysis of an engine jet on an aircraft blast deflector

2018 ◽  
Vol 41 (4) ◽  
pp. 990-1001
Author(s):  
Song Ma ◽  
Jianguo Tan ◽  
Xiankai Li ◽  
Jiang Hao
Keyword(s):  
High Temperature ◽  
Flow Field ◽  
High Speed ◽  
Deflection Angle ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Aircraft Engine ◽  
Experimental Results ◽  
Exhaust Gases ◽  
The Impact

This paper establishes a novel mathematical model for computing the plume flow field of a carrier-based aircraft engine. Its objective is to study the impact of jet exhaust gases with high temperature, high speed and high pressure on the jet blast deflector. The working condition of the nozzle of a fully powered on engine is first determined. The flow field of the exhaust jet is then numerically simulated at different deflection angle using the three-dimensional Reynolds averaged Navier–Stokes equations and the standard [Formula: see text]-[Formula: see text] turbulence method. Moreover, infra-red temperature tests are further carried out to test the temperature field when the jet blast deflector is at the [Formula: see text] deflection angle. The comparison between the simulation results and the experimental results show that the proposed computation model can perfectly describe the system. There is only 8–10% variation between them. A good verification is achieved. Moreover, the experimental results show that the jet blast deflector plays an outstanding role in driving the high-temperature exhaust gases. It is found that [Formula: see text] may be the best deflection angle to protect the deck and the surrounding equipment effectively. These data results provide a valuable basis for the design and layout optimization of the jet blast deflector and deck.

Effects of Flow Injection From Outer Casing Upon Turbine Nozzle Vane Flow Field

2002 ◽  
Author(s):  
K. Funazaki ◽  
C. F. F. Favaretto ◽  
T. Tanuma
Keyword(s):  
Flow Field ◽  
Flow Injection ◽  
Three Dimensional ◽  
Leading Edge ◽  
Main Stream ◽  
Flow Angle ◽  
Aerodynamic Loss ◽  
Nozzle Vane ◽  
Design Variables ◽  
The Impact

In the present paper steady three-dimensional numerical calculations were performed in order to investigate the effects of flow injection from the outer casing upon turbine nozzle vane flow field. Several test cases were analyzed by applying different nozzle vane configurations such as the blade lean, injection slot width and distance from the leading edge. Numerical simulations were conducted considering the no injection case, 5% and 10% main stream flow injection from the outer casing. The impact of the flow injection design variables and the blade lean angle on the aerodynamic loss in terms of the energy loss coefficient and the outlet flow angle were analyzed through a parametric study.

Numerical Research on Flow Field Characteristics within the Slipstream of a Propeller

2012 ◽  
Vol 224 ◽  
pp. 55-60
Author(s):  
Zhong Zhe Duan ◽  
Pei Qing Liu ◽  
Li Chuan Ma
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Scientific Basis ◽  
Disk Model ◽  
Actuator Disk ◽  
Numerical Result ◽  
Light Load ◽  
Strip Theory ◽  
Flow Field Characteristics ◽  
Numerical Research

Numerical research on three dimensional flow field of a propeller and actuator disk model have been made. Under design conditions (headway 66.889m/s, revolving velocity 2575rpm）, the Slipstream flow field after Propeller is solved by RANS equations with structure mesh. Chosen 12 million mesh through verification of reliability analysis. The numerical result consists of the flow field and vortex field in the propeller slipstream. With comparison to the calculation result of standard strip theory and actuator disk model, it is shown that for light load propeller with the side small contraction of slipstream, in the slipstream cross section after 0.6R away from downstream of propeller rotation plane, the axial, circular and radial induced velocity coefficient by Prandtl’s blade tip corrected standard strip theory result; three dimensional flows numerical simulation and actuator disk model are well consistent. It verified the correctness of standard strip theory and also provided scientific basis for the correction of actuator disk model

scholarly journals Three-Dimensional Numerical Analysis of LOX/Kerosene Engine Exhaust Plume Flow Field Characteristics

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hong-hua Cai ◽  
Wan-sheng Nie ◽  
Xin-lei Yang ◽  
Rui Wu ◽  
Ling-yu Su
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Chemical Reaction ◽  
Reaction Mechanisms ◽  
Three Dimensional ◽  
Engine Exhaust ◽  
Exhaust Plume ◽  
Flow Field Characteristics ◽  
Chemical Reaction Mechanisms ◽  
Plume Flow

Aiming at calculating and studying the flow field characteristics of engine exhaust plume and comparative analyzing the effects of different chemical reaction mechanisms on the engine exhaust plume flow field characteristics, a method considering fully the combustion state influence is put forward, which is applied to exhaust plume flow field calculation of multinozzle engine. On this basis, a three-dimensional numerical analysis of the effects of different chemical reaction mechanisms on LOX/kerosene engine exhaust plume flow field characteristics was carried out. It is found that multistep chemical reaction can accurately describe the combustion process in the LOX/kerosene engine, the average chamber pressure from the calculation is 4.63% greater than that of the test, and the average chamber temperature from the calculation is 3.34% greater than that from the thermodynamic calculation. The exhaust plumes of single nozzle and double nozzle calculated using the global chemical reaction are longer than those using the multistep chemical reaction; the highest temperature and the highest velocity on the plume axis calculated using the former are greater than that using the latter. The important influence of chemical reaction mechanism must be considered in the study of the fixing structure of double nozzle engine on the rocket body.

Numerical Simulation of Flow Process of Ammonium Persulfate Crystallizer

2014 ◽  
Vol 997 ◽  
pp. 396-400
Author(s):  
Yu Guang Fan ◽  
Ting Wei
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Three Dimensional ◽  
Ammonium Persulfate ◽  
Flow Process ◽  
Calculation Results ◽  
Crystallization Effect ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Selection Of

The method of computational fluid dynamics (CFD) is used to three-dimensional numerical simulation for the fluid flow process of ammonium persulfate crystallizer. By using standard model, this paper respectively simulated the flow field within the crystallizer in the impeller installation height of 1.2 m while stirring speed is of 60 r/min, 100 r/min and 200 r/min; and simulated the impact of the flow field inside the crystallizer when the stirring speed of 100 r/min and impeller installation height respectively is of 0.7 m, 1.2 m and 1.7 m. That calculation results show that: the velocity gradient is mainly concentrated in the area of internal draft tube and paddle around. With the increase of impeller speed, the flow velocity of the fluid within the crystallizer corresponding increases; and the energy also gradually decreases from mixing impeller to the settlement zone with the loss of the installation height, and the kinetic energy in the bottom of the crystallizer is reduced. Considering the energy and crystallization effect, selection of mixing speed of 100 r/min or so and installation height of about 1.2 m is more appropriate.

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