Numerical Analysis on the Internal Flow Field Characteristics of Wind Tunnel According to the Change of Contraction Length

2018 ◽  
Vol 22 (4) ◽  
pp. 81-88 ◽  
Author(s):  
Seok-Hyung Oh ◽  
Jang-Kweon Kim
Keyword(s):  
Numerical Analysis ◽  
Wind Tunnel ◽  
Flow Field ◽  
Internal Flow ◽  
Flow Field Characteristics

Numerical Analysis on the Internal Flow Field and Adsorption Performance of a Non-Contact Vortex Gripper

2013 ◽  
Vol 433-435 ◽  
pp. 1959-1964 ◽  
Author(s):  
Zhi Jian Zheng ◽  
Dong Tai Liang ◽  
Bo Lu ◽  
Jun Hui Huang
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Working Conditions ◽  
Negative Pressure ◽  
Swirling Flow ◽  
Internal Flow ◽  
Pressure Center ◽  
Adsorption Performance ◽  
Maximum Value ◽  
Flow Field Characteristics

Based on the establishment of the geometry and equations of non-contact vortex gripper, the numerical analysis of the internal flow field characteristics and the key parameters affecting the adsorption performance was carried out. The results showed that: for the single air-entrance gripper, the negative pressure center not coincides at the geometric center of the gripper. Besides, with the movement of swirling flow, the position of the negative pressure center transformed; When the geometric parameters and working conditions are fixed, there is the most suitable air gap making the maximum value of negative pressure and adsorption force; Compared to single air-entrance gripper, double air-entrance gripper have better adsorption stability.

Numerical Analysis of Flow Field Characteristics in Three-Z-Shaped Ultrasonic Flowmeter

2012 ◽  
Vol 226-228 ◽  
pp. 1829-1834 ◽  
Author(s):  
Jing Yuan Tang ◽  
Jian Ming Chen ◽  
Hong Bin Ma ◽  
Guang Yu Tang
Keyword(s):  
Flow Field ◽  
Cross Sections ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Internal Flow ◽  
Reynolds Stress Model ◽  
Ultrasonic Flowmeter ◽  
Developed Turbulence ◽  
Fluid Field ◽  
Flow Field Characteristics

The flow field characteristics in U-typed bend has been extensively studied for transit time ultrasonic flowmeters designing, but for the flowmeter with three-Z-shaped round pipe there is still lack of corresponding research. This paper presents a computational fluid dynamics (CFD) approach for modeling of the three-Z-shaped ultrasonic flowmeter and studying of internal fluid field characteristics based on Reynolds stress model (RSM). The fluid velocity profile in the three ultrasound path is obtained using CFD and secondary flow in cross section also is analyzed. The simulation results show that the internal flow fields in the flowmeter are not fully developed turbulence with asymmetric axial velocity distribution and dramatic changes along the flow direction, and there are obvious secondary cross flows on theirs cross-sections. The CFD simulations provide useful insights into the flow field associated with ultrasonic flowmeters design.

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.

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