Simulation on Hydraulic Performance of Two Kinds of Coring Diamond Bits with Different Crown

2012 ◽  
Vol 497 ◽  
pp. 350-355 ◽  
Author(s):  
Yan Chen ◽  
Zhi Yi Liu ◽  
Long Chen Duan
Keyword(s):  
Flow Field ◽  
Negative Pressure ◽  
Eddy Currents ◽  
Drilling Fluid ◽  
Cross Flow ◽  
Hydraulic Performance ◽  
Direction Vector ◽  
Flat Bottom ◽  
Field Simulation ◽  
Drilling Bit

The software CFDesign was used for the analysis of flow field simulation of two different kinds of drilling bit. The results showed that, if the waterway design of drilling bit was unreasonable, it could result in the following phenomenon: the local position of drilling bit could get severe erode of drilling fluid; the return of flow and eddy currents could be observed in the bottom of drilling well; negative pressure could be detected and might result in cavitation corrosion; the direction vector of flow field were diffused and resulted in cross flow. The waterway structure of arc-bottom bit was more reasonable comparing that of flat-bottom bit.

scholarly journals Cross-Flow Tidal Turbines with Highly Flexible Blades—Experimental Flow Field Investigations at Strong Fluid–Structure Interactions

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 797
Author(s):  
Stefan Hoerner ◽  
Iring Kösters ◽  
Laure Vignal ◽  
Olivier Cleynen ◽  
Shokoofeh Abbaszadeh ◽  
...  
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Cross Flow ◽  
Speed Ratio ◽  
Fluid Structure Interactions ◽  
Dimensional Parameter ◽  
Fluid Structure ◽  
Passive Flow Control ◽  
Tidal Turbines ◽  
Tidal Turbine

Oscillating hydrofoils were installed in a water tunnel as a surrogate model for a hydrokinetic cross-flow tidal turbine, enabling the study of the effect of flexible blades on the performance of those devices with high ecological potential. The study focuses on a single tip-speed ratio (equal to 2), the key non-dimensional parameter describing the operating point, and solidity (equal to 1.5), quantifying the robustness of the turbine shape. Both parameters are standard values for cross-flow tidal turbines. Those lead to highly dynamic characteristics in the flow field dominated by dynamic stall. The flow field is investigated at the blade level using high-speed particle image velocimetry measurements. Strong fluid–structure interactions lead to significant structural deformations and highly modified flow fields. The flexibility of the blades is shown to significantly reduce the duration of the periodic stall regime; this observation is achieved through systematic comparison of the flow field, with a quantitative evaluation of the degree of chaotic changes in the wake. In this manner, the study provides insights into the mechanisms of the passive flow control achieved through blade flexibility in cross-flow turbines.

Flow Field Simulation of the Solo-Supported High Pressure Gas Device of Double-Layer Air Jet Looms

2011 ◽  
Vol 101-102 ◽  
pp. 512-515
Author(s):  
Yi Sheng Liu ◽  
Xu Dong Hu ◽  
Peng Dong Su
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Flow Velocity ◽  
Double Layer ◽  
Research Program ◽  
Flow Channel ◽  
Feasibility Analysis ◽  
Middle Line ◽  
Air Jet ◽  
Field Simulation

A research program is currently underway with the purpose of developing a double-layer air jet looms with solo-supported gas device. Issues related to the design and feasibility analysis of the solo-supported high pressure gas device are discussed. The results of simulations show that assistant nozzle is necessary during weft insertion motion, but too many assistant nozzles would cause the flow velocity reduce. And it is confirmed that flow channel with one main and four assistant nozzles is one of the best designs to keep the flow velocity at the middle line of flow channel more than 90m/s and make the loom work swimmingly.

Study of Flow Field in Compact Spinning with Pneumatic Groove

2011 ◽  
Vol 332-334 ◽  
pp. 260-263
Author(s):  
Shi Rui Liu
Keyword(s):  
Flow Field ◽  
Negative Pressure ◽  
Static Pressure ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Compact Zone ◽  
Air Flows ◽  
Compact Spinning

In the paper the structure of the compact spinning with pneumatic groove is introduced and the characteristics of three-dimensional flow field of the compact spinning with pneumatic groove are also investigated. Results from this research confirmed that In the compact zone, the air flows to the groove and enters the inner hollow of the slot-roller through the round holes, and the air on both sides of the groove condenses to the center of it and flows to the round holes; It is beneficial to compact the fiber and make the fiber slip to the bottom of the groove with shrink shape; the velocity and negative pressure are both not homogeneous, as the round holes are not continual, and the gradient of static pressure and velocity in compact zones are also perceptible.

The Influence of Wrap Angle of Blade on the Internal Flow Field and Hydraulic Performance of Double Suction Pump

2018 ◽  
Author(s):  
Hao Chang ◽  
Weidong Shi ◽  
Wei Li ◽  
Jianrui Liu ◽  
Ling Zhou ◽  
...  
Keyword(s):  
Flow Field ◽  
Cross Section ◽  
Turbulence Model ◽  
Static Pressure ◽  
Internal Flow ◽  
Hydraulic Performance ◽  
Optimal Model ◽  
Suction Pump ◽  
External Characteristic ◽  
Wrap Angle

In order to study the influence rule of wrap angle of blade on the internal flow field and hydraulic performance of double suction pump, 5 kinds of wrap angles of blade with 100°, 110°, 120°, 130° and 140° are designed in this paper. The turbulence model and the grid type are analyzed, the performance of ES350-575 double suction pump is obtained by employ the software CFX. The static pressure and velocity distributions in the cross-section are analyzed. Therefore, the optimal model is obtained, and the relevant external characteristic test is conducted. The result shows that the reasonable increase of the wrap angle of blade can enhance the performance of the pump effectively, which can improve the static pressure and velocity distributions of the internal flow field.

scholarly journals Flow field simulation of the spiral-wound heat exchanger

2018 ◽  
Vol 1064 ◽  
pp. 012003
Author(s):  
Guanghui Chen ◽  
Jie Bao ◽  
Shu Guo ◽  
Jianlong Li
Keyword(s):  
Heat Exchanger ◽  
Flow Field ◽  
Flow Field Simulation ◽  
Field Simulation ◽  
Spiral Wound
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