Estimation of pressure field and maximum velocity of an oseen vortex

2018 ◽  
Author(s):  
Musawar Hussain ◽  
Syed Irtiza Ali Shah
Keyword(s):  
Pressure Field ◽  
Maximum Velocity ◽  
Oseen Vortex

Study of a Turbulent Dual Jet Consisting of a Wall Jet and an Offset Jet

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
Amitesh Kumar ◽  
Manab Kumar Das
Keyword(s):  
Reynolds Number ◽  
Dissipation Rate ◽  
Momentum Flux ◽  
High Reynolds Number ◽  
Pressure Field ◽  
Maximum Velocity ◽  
Wall Jet ◽  
High Reynolds ◽  
Merge Point ◽  
Offset Jet

The study of a two-dimensional, steady, incompressible, turbulent flow of a dual jet consisting of a wall jet and an offset jet has been simulated numerically. The standard high Reynolds number two-equation k-ɛ model is used as the turbulence model. The Reynolds number is considered as 20000 for all the computations because the flow becomes fully turbulent. The merge point and the combined point have been obtained and compared with other results. The central streamline has been plotted and observed to follow an arc of a circle. The momentum flux has been computed along the axial length for the wall jet, offset jet and the dual jet and compared. A similarity profile has been obtained in the downstream direction. A detailed discussion has been provided on the pressure field, Reynolds stress, kinetic energy and its dissipation rate. The jet growth rate in terms of half-width, the decay of maximum velocity and the jet width are presented

Umbilical artery time-averaged maximum velocity: First trimester reference range

2014 ◽  
Vol 74 (S 01) ◽  
Author(s):  
SK Amylidi ◽  
P Tappeser ◽  
B Mosimann ◽  
J Zdanowicz ◽  
M Baumann ◽  
...  
Keyword(s):  
Umbilical Artery ◽  
Reference Range ◽  
Maximum Velocity ◽  
First Trimester

Sources of Variability in Dose Response Platelet Aggregometry

1985 ◽  
Vol 53 (02) ◽  
pp. 219-220 ◽  
Author(s):  
M V Vickers ◽  
S G Thompson
Keyword(s):  
Dose Response ◽  
Maximum Velocity ◽  
Adenosine Diphosphate ◽  
Method Error ◽  
Platelet Aggregability ◽  
Differential Effects ◽  
Platelet Aggregometry ◽  
Simultaneous Comparison ◽  
Aggregation Parameters ◽  
Very High

SummaryAn experiment designed to assess the components of variability of a number of measures of platelet aggregability showed that the ADP ED50 (the estimated dose of adenosine diphosphate at which primary aggregation occurs at half its maximum velocity) had the least method error of any of the parameters measured, but that none had a very high between-person component of variability. A simultaneous comparison of a syringe technique and a free-flowing technique for venepuncture revealed no differential effects on the aggregation parameters measured. An enforced increase in the stirring speed in the aggregometer led to an experiment which showed that such a change did not apparently affect the ED50s.

Decay of fluctuating wall-pressure field of Mach 5 turbulent boundary layer

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 1088-1096
Author(s):  
O. H. Unalmis ◽  
D. S. Dolling
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Pressure Field ◽  
Wall Pressure

Simulation of Two Phase Flow Dynamics in Flexible Riser Exit Geometries for Oil and Gas Applications

2018 ◽  
Vol 39 ◽  
pp. 1-13
Author(s):  
Ikpe E. Aniekan ◽  
Owunna Ikechukwu ◽  
Satope Paul
Keyword(s):  
Oil And Gas ◽  
Two Phase Flow ◽  
Flow Analysis ◽  
Computational Cost ◽  
Maximum Velocity ◽  
Oil Well ◽  
Phase Flow ◽  
Two Phase ◽  
The Third ◽  
Riser Pipe

Four different riser pipe exit configurations were modelled and the flow across them analysed using STAR CCM+ CFD codes. The analysis was limited to exit configurations because of the length to diameter ratio of riser pipes and the limitations of CFD codes available. Two phase flow analysis of the flow through each of the exit configurations was attempted. The various parameters required for detailed study of the flow were computed. The maximum velocity within the pipe in a two phase flow were determined to 3.42 m/s for an 8 (eight) inch riser pipe. After thorough analysis of the two phase flow regime in each of the individual exit configurations, the third and the fourth exit configurations were seen to have flow properties that ensures easy flow within the production system as well as ensure lower computational cost. Convergence (Iterations), total pressure, static pressure, velocity and pressure drop were used as criteria matrix for selecting ideal riser exit geometry, and the third exit geometry was adjudged the ideal exit geometry of all the geometries. The flow in the third riser exit configuration was modelled as a two phase flow. From the results of the two phase flow analysis, it was concluded that the third riser configuration be used in industrial applications to ensure free flow of crude oil and gas from the oil well during oil production.

scholarly journals Two-dimensional flow field distribution characteristics of flocking drainage pipes in tunnel

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 139-148
Author(s):  
Shiyang Liu ◽  
Xuefu Zhang ◽  
Feng Gao ◽  
Liangwen Wei ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Field Distribution ◽  
Rapid Development ◽  
Maximum Velocity ◽  
Distribution Characteristics ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Laboratory Test Results ◽  
Transverse Distance ◽  
Two Dimensional Flow

AbstractWith the rapid development of traffic infrastructure in China, the problem of crystal plugging of tunnel drainage pipes becomes increasingly salient. In order to build a mechanism that is resilient to the crystal plugging of flocking drainage pipes, the present study used the numerical simulation to analyze the two-dimensional flow field distribution characteristics of flocking drainage pipes under different flocking spacings. Then, the results were compared with the laboratory test results. According to the results, the maximum velocity distribution in the flow field of flocking drainage pipes is closely related to the transverse distance h of the fluff, while the longitudinal distance h of the fluff causes little effect; when the transverse distance h of the fluff is less than 6.25D (D refers to the diameter of the fluff), the velocity between the adjacent transverse fluffs will be increased by more than 10%. Moreover, the velocity of the upstream and downstream fluffs will be decreased by 90% compared with that of the inlet; the crystal distribution can be more obvious in the place with larger velocity while it is less at the lower flow rate. The results can provide theoretical support for building a mechanism to deal with and remove the crystallization of flocking drainage pipes.

scholarly journals An Electrostatic Self-Excited Resonator with Pre-Tension/Pre-Compression Constraint for Active Rotation Control

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 650
Author(s):  
Ruide Yun ◽  
Yangsheng Zhu ◽  
Zhiwei Liu ◽  
Jianmei Huang ◽  
Xiaojun Yan ◽  
...  
Keyword(s):  
Maximum Velocity ◽  
Flapping Wings ◽  
Variable Velocity ◽  
Beam Length ◽  
Dc Voltage ◽  
Middle Position ◽  
Simply Supported ◽  
Maximum Value ◽  
Constraint Structure

We report a novel electrostatic self-excited resonator driven by DC voltage that achieves variable velocity-position characteristics via applying the pre-tension/pre-compression constraint. The resonator consists of a simply supported micro-beam, two plate electrodes, and two adjustable constraint bases, and it can be under pre-compression or pre-tension constraint by adjusting the distance L between two constraint bases (when beam length l > L, the resonator is under pre-compression and when l < L, it is under pre-tension). The oscillating velocity of the beam reaches the maximum value in the position around electrodes under the pre-compression constraint and reaches the maximum value in the middle position between two electrodes under the pre-tension condition. By changing the constraint of the microbeam, the position of the maximum velocity output of the oscillating beam can be controlled. The electrostatic self-excited resonator with a simple constraint structure under DC voltage has great potential in the field of propulsion of micro-robots, such as active rotation control of flapping wings.

Airborne flow dynamics near free-falling bulk materials: CFD analysis from analytical pressure field

2021 ◽  
Vol 385 ◽  
pp. 1-11
Author(s):  
Rodrigo Xavier de Almeida Leão ◽  
Leandro Silva Amorim ◽  
Marcio Ferreira Martins ◽  
Humberto Belich Junior ◽  
Enrico Sarcinelli ◽  
...  
Keyword(s):  
Pressure Field ◽  
Flow Dynamics ◽  
Cfd Analysis ◽  
Bulk Materials ◽  
Free Falling
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