On the Pressure and Force Field on a Circular Cylinder Oscillating in the Lock-In Region at Sub-Critical Reynolds Number

2006 ◽  
Author(s):  
Alberto Zasso ◽  
Marco Belloli ◽  
Stefano Giappino ◽  
Sara Muggiasca
Keyword(s):  
Force Field ◽  
Pressure Distribution ◽  
Velocity Ratio ◽  
Power Input ◽  
Interaction Force ◽  
Cylinder Surface ◽  
Force Component ◽  
Fundamental Parameters ◽  
Technical Interest ◽  
Lock In

The vortex induced vibration of a rigid cylinder has been studied in the subcritical Reynolds range in terms of motion parameters and also in terms of instantaneous pressure distribution on the cylinder surface. The resulting force field has been analyzed as a function of the fundamental parameters z* (non-dimensional amplitude) and Un (critical velocity ratio) showing a possible systematic modelization of the force component synchronous with the oscillation frequency, responsible for the power input in the lock-in region. The magnitude and the phase of the synchronous force component have been studied analyzing build-up events as well as steady state constant amplitude oscillation events. A very close correspondence has been highlighted among the two different analyzed cases, confirming that a quasi-steady model of the force field is a robust and reliable representation of the flow-cylinder interaction force field. This interaction is responsible for the typical transient build-up oscillations of technical interest. The pressure distribution monitored at different locations along the oscillating cylinder axial coordinate allowed finally to show a direct link between the incoming flow velocity distribution and the correlation characteristics of the vortex shedding force distribution along the cylinder axis.

Local electric field factors by a combined charge-transfer and point–dipole interaction model

RSC Advances ◽  
2015 ◽  
Vol 5 (40) ◽  
pp. 31594-31605 ◽  
Author(s):  
Nazanin Davari ◽  
Shokouh Haghdani ◽  
Per-Olof Åstrand ◽  
George C. Schatz
Keyword(s):  
Charge Transfer ◽  
Electric Field ◽  
Force Field ◽  
Linear Response ◽  
Field Model ◽  
Interaction Model ◽  
Dipole Interaction ◽  
Interaction Force ◽  
Local Electric Field ◽  
Point Dipole

A model for the local electric field as a linear response to a frequency-dependent external electric field is presented based on a combined charge-transfer and point–dipole interaction force-field model.

A theoretical analysis of the calendering of Ellis fluid

2016 ◽  
Vol 33 (2) ◽  
pp. 207-226 ◽  
Author(s):  
Muhammad Asif Javed ◽  
Nasir Ali ◽  
Muhammad Sajid
Keyword(s):  
Theoretical Analysis ◽  
Velocity Profile ◽  
Pressure Gradient ◽  
Pressure Distribution ◽  
Sheet Thickness ◽  
Power Input ◽  
Lubrication Approximation ◽  
Material Parameters ◽  
Operating Variables ◽  
Roll Separating Force

We present a theoretical analysis of calendering of Ellis fluid based on lubrication approximation. The equations governing the flow are nondimensionalized and solved to get closed form expressions of velocity and pressure gradient. Runge–Kutta algorithm is employed to compute the pressure distribution. The operating variables which are used in the calendering process, i.e. roll-separating force, power input to the rolls and exiting sheet thickness are calculated. The influence of the material parameters on the velocity profile, pressure gradient, pressure distribution and operating variables is shown graphically and discussed in detail.

scholarly journals An Exploratory View on Relationship between Space Dimensionality and Interaction Force among Objects

2021 ◽  
pp. 1-5
Author(s):  
Zhou u Xinli ◽  
Keyword(s):  
Force Field ◽  
Theoretical Foundation ◽  
Interaction Force ◽  
Dynamic Relationship

To thoroughly explore and analyze the space dimensionality as well as the dynamic relationship between itself and the motion of objects, the author of this paper applies the approach of mathematical sets so as to discover the essential discipline of motion and motionlessness in the astrospace, and the author also tries to find perfect answers to the not-yet-satisfactorily-explained questions or phenomena in modern physical theories, providing a new theoretical foundation for the research on uniform force field

Computation of Vortex Lock-In in the Laminar Wake of a Circular Cylinder Using Unsteady Monopole Sources

1995 ◽  
Vol 117 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Dartzi Pan ◽  
Yu-Chi Chin ◽  
Chih-Hao Chang
Keyword(s):  
Circular Cylinder ◽  
Flow Field ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Finite Volume Scheme ◽  
Cylinder Surface ◽  
Navier Stokes Equations ◽  
Laminar Wake ◽  
Lock In ◽  
Flux Difference

The vortex lock-in in the laminar wake behind a circular cylinder induced by the unsteady monopole source is numerically simulated in this paper. The artificial compressibility method is employed to solve the incompressible Navier-Stokes equations. A high-order accurate upwind flux-difference finite-volume scheme is used to discretize the flow field. The unsteady monopole source is simulated by a pulsating volume flux through the cylinder surface at a prescribed forcing frequency and amplitude. The forcing amplitude is set to a fixed value while the frequency is varied to search for the lock-in region. The flow field of the periodic lock-in state is examined in detail. Finally, the effects of a higher amplitude and a different source location are briefly investigated.

The Monitoring and Analysis of the Anti-Slide Pile’s Pile-Soil Interaction

2014 ◽  
Vol 633-634 ◽  
pp. 952-957
Author(s):  
Nian Qin Wang ◽  
Yao Qiong Xue ◽  
Xiao Yu Cheng ◽  
Jing Rui Wei
Keyword(s):  
Tensile Stress ◽  
Pressure Distribution ◽  
Compressive Stress ◽  
Slip Surface ◽  
Earth Pressure ◽  
Interaction Force ◽  
Soil Pressure ◽  
High Slope ◽  
Distribution Form ◽  
Pile Cap

In the landslide disaster control and high slope strengthening engineering, anti-slide pile is one of trusted engineering measures, but cognition in aspect of forced state on the anti-slide pile, the pile-soil mechanism etc, which should be strengthened. Therefore, monitoring objects with three cantilever anti-slide pile entities in the loess high slope somewhere, burying monitoring instruments such as earth pressure cells and steel bar meter, for as long as 18 months of monitoring. Through analysis of monitoring results, can draw the following conclusion:①The soil pressure distribution form before the anti-slide piles is parabola-shape as a whole, whatever above the slip surface or under the slip surface the soil pressure distribution form behind the anti-slide piles is almost triangle as a whole;②The anti-slide piles construction are completed, pile-soil interaction force and reinforced by stress reaches stability in about 16 months;③A maximum soil pressure before the anti-slide piles on the ground, the soil pressure behind the anti-slide piles near the potential sliding surface;④Before the anti-slide piles and behind the anti-slide piles, reinforced by stress from pile cap to pile bottom respectively is "compressive stress and tensile stress" and "compressive stress, tensile stress and compressive stress, tensile and compressive stress of zero before pile is tensile stress value maximize after pile.

Pressure distribution under different types of blood pressure measurement cuffs

2016 ◽  
Vol 47 (1) ◽  
pp. 89-103 ◽  
Author(s):  
Shenela Naqvi ◽  
Muhammad Dawood Husain ◽  
Prasad Potluri ◽  
Parthasarathi Mandal ◽  
Philip Lewis
Keyword(s):  
Mechanical Properties ◽  
Blood Pressure ◽  
Pressure Distribution ◽  
Pressure Measurement ◽  
Blood Pressure Measurement ◽  
Principal Component ◽  
Cylinder Surface ◽  
Interface Pressure ◽  
Metal Cylinder ◽  
Different Types

The principal component of any non-invasive blood pressure measurement system is an inflatable cuff. Different types of fabrics are used for inflatable cuffs construction. In this study, sphygmomanometric blood pressure measurement using inflatable cuffs was simulated in Abaqus and validated through experimental results. The purpose of the simulation is to study the effect of variation in cuff fabric geometric and mechanical properties on pressure distribution and pressure transmission during blood pressure measurement by predicting the pressure at the interface of the blood pressure cuffs and a metal cylinder. Geometric and mechanical properties of the fabrics of four different cuff types were found experimentally. Interface pressure at the cuffs and metal cylinder surface was also found experimentally using Tekscan pressure sensing system for models validation. The results of the simulation showed that the interface pressure underneath the cuffs vary with variation in geometric and mechanical properties of their fabrics. The results of the simulation were found to be in good agreement with experimental findings. This research demonstrates that the pressure distribution under the cuffs is related to the cuffs' fabric geometric and mechanical properties. This means that variation in cuffs' fabric properties could ultimately incur variations in the blood pressure values of human subjects.

scholarly journals Distribution of ring pressure over a worn cylinder liner surface

2015 ◽  
Vol 161 (2) ◽  
pp. 53-63
Author(s):  
Wojciech SERDECKI ◽  
Piotr KRZYMIEŃ
Keyword(s):  
Pressure Distribution ◽  
High Probability ◽  
Cylinder Liner ◽  
Cylinder Surface ◽  
Engine Operation ◽  
Compression Ring ◽  
Complete Ring ◽  
Liner Surface ◽  
The Dead ◽  
Operational Data

A trial to define the effect of changes in cylinder geometry on compression ring pressure distribution has been presented in this paper which refers to the earlier papers of the authors. The analysis encompasses these cylinders where both circumferential and axial deformations occurred, relative to constructional and assembly errors but above all to engine operation. The conclusions withdrawn from these analyses were applied to exemplary calculations that try to evaluate the effect of cylinder deformation on correct collaboration of ring and liner and particularly on possibility of circumferential gaps leading to blow-by. The drafts presented in the paper show exemplary results of ring pressure distribution for a complete ring path between the dead centers and selected engine operational data. Moreover, such areas of cylinder surface were shown where slots between compression ring and cylinder liner might occur with high probability.

Study on the Pressure Distribution on Solid-Plug Conveying of Centrifugal Extruder

2013 ◽  
Vol 690-693 ◽  
pp. 2928-2932
Author(s):  
Jing Zhao ◽  
Shi Jie Wang ◽  
Xiao Ren Lv
Keyword(s):  
Theoretical Analysis ◽  
Force Field ◽  
Pressure Distribution ◽  
Influencing Factors ◽  
Centrifugal Force ◽  
Structural Parameters ◽  
Rotation Velocity ◽  
Centrifugal Force Field

In this paper, a new polymer process machine--- centrifugal extruder is introduced. The performance of centrifugal extruder had been studied by theoretical analysis. The analysis shows that the centrifugal force field can provide the solid-plug conveying pressure sufficiently and stably, which can prove the industry practicability of centrifugal extrude. By further discussion, it shows that the important influencing factors on the pressure comprise the structural parameters of the rotors and the rotation velocity.

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