Influence of Viscosity on Forcespinning™ Dynamics

2012 ◽  
Author(s):  
Simon Padron ◽  
Dumitru I. Caruntu ◽  
Karen Lozano
Keyword(s):  
Fluid Dynamics ◽  
Multiple Scales ◽  
Tangential Velocity ◽  
Centrifugal Forces ◽  
Dynamics Model ◽  
Novel Method ◽  
The Finite Difference Method ◽  
Jet Theory ◽  
High Yields ◽  
Fluid Dynamics Equations

Forcespinning™ is a novel method that makes use of centrifugal forces to produce nanofibers rapidly and at high yields. A 2D computational Forcespinning™ viscous fluid dynamics model is developed, that improves on previous models. The fluid dynamics equations are solved using themethod of multiple scales along with the finite difference method, and including slender-jet theory assumptions. The effects that the Reynolds (Re) number has on the resulting fiber trajectory, radius, and tangential velocity are presented.

On 2D Forcespinning™ Modeling

2011 ◽  
Author(s):  
Simon Padron ◽  
Dumitru I. Caruntu ◽  
Karen Lozano
Keyword(s):  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Fiber Diameter ◽  
Production Method ◽  
Fiber Formation ◽  
Centrifugal Forces ◽  
Governing Equations ◽  
Novel Method ◽  
Jet Theory ◽  
High Yields

Forcespinning™ is a novel method that makes used of centrifugal forces to produce nanofibers rapidly and at high yields. To improve and enhance this new nanofiber production method a model of the system is begun. The process is started by deriving the governing equations of the forcespinning™ sytem and the constraints associated it. A simple 2D model is then obtained using the derived governing equations for the inviscid case to determine the trends of fiber diameter and trajectories. Then, focus is given to the time-dependency of these equations, and the effects of parametric excitation of the system on fiber formation are analyzed. The equations are solved using a combination of the method of multiple scales and the finite difference method with slender-jet theory assumptions.

scholarly journals An immersed-shell method for modelling fluid–structure interactions

2015 ◽  
Vol 373 (2035) ◽  
pp. 20140085 ◽  
Author(s):  
A. Viré ◽  
J. Xiang ◽  
C. C. Pain
Keyword(s):  
Fluid Dynamics ◽  
Structural Dynamics ◽  
Thin Shell ◽  
Concentration Field ◽  
Fluid Structure Interactions ◽  
Fundamental Interest ◽  
Fluid Structure ◽  
Computational Mesh ◽  
Novel Method ◽  
Fluid Dynamics Equations

The paper presents a novel method for numerically modelling fluid–structure interactions. The method consists of solving the fluid-dynamics equations on an extended domain, where the computational mesh covers both fluid and solid structures. The fluid and solid velocities are relaxed to one another through a penalty force. The latter acts on a thin shell surrounding the solid structures. Additionally, the shell is represented on the extended domain by a non-zero shell-concentration field, which is obtained by conservatively mapping the shell mesh onto the extended mesh. The paper outlines the theory underpinning this novel method, referred to as the immersed-shell approach. It also shows how the coupling between a fluid- and a structural-dynamics solver is achieved. At this stage, results are shown for cases of fundamental interest.

2-D Modeling of Nonlinear Dynamics of Forcespinning Jet Formation

2021 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Simon Padron ◽  
Karen Lozano
Keyword(s):  
Fluid Dynamics ◽  
Angular Velocity ◽  
Multiple Scales ◽  
Tangential Velocity ◽  
Production Method ◽  
Orifice Diameter ◽  
Inviscid Fluid ◽  
Exit Angle ◽  
Fluid Level ◽  
Jet Trajectory

Abstract Forcespinning is a novel method that makes use of centrifugal forces to produce nanofibers rapidly and at high yields. To improve and enhance the forcespinning production method, a 2D computational forcespinning inviscid fluid dynamics model is developed. Two models, namely time-independent and time-dependent, are obtained in order to investigate the influence of various parameters on fiber forcespinning formation (trajectory, jet diameter, tangential velocity). The fluid dynamics equations are solved using the method of multiple scales along with the finite difference method, and including slender-jet theory assumptions. It is important to produce jets with small diameters in the micro- and nano-range. The Weber (We) and Rossby (Rb) numbers were found to both expand the jet trajectory as they increased. Increasing We and/or decreasing Rb was found to decrease the jet diameter. Also, by varying forcespinning parameters, it has been found that the jet radius can be decreased by increasing the jet exit angle in the direction of rotation, reducing the spinneret fluid level, increasing the angular velocity of the spinneret, reducing spinneret length, and/or reducing the orifice diameter. Knowing the jet trajectories is important for designing and positioning of fiber collector. It has been found that the trajectories expand out with the increase of the jet exit angle in the direction of rotation, increase of fluid level, increase of angular velocity, and/or increase of the spinneret length. Production rates and jet radii for any predetermined radial collector distance were also determined.

A Novel Method for the Rapid Purification of Human and Rat Fibrin(OGEN) Degradation Products in High Yields

1979 ◽  
Author(s):  
W. Nieuwenhuizen ◽  
I. A. M. van Ruijven-Vermeer ◽  
F. Haverkate ◽  
G. Timan
Keyword(s):  
Degradation Products ◽  
Complete Separation ◽  
Purification Method ◽  
Amino Terminal ◽  
Novel Method ◽  
Rapid Purification ◽  
The One ◽  
High Yields ◽  
Size Heterogeneity ◽  
D Dimer

A novel method will be described for the preparation and purification of fibrin(ogen) degradation products in high yields. The high yields are due to two factors. on the one hand an improved preparation method in which the size heterogeneity of the degradation products D is strongly reduced by plasmin digestion at well-controlled calcium concentrations. At calcium concentrations of 2mM exclusively D fragments, M.W.= 93-000 (Dcate) were formed; in the presence of 1OmM EGTA only fragments M.W.= 80.000 (D EGTA) were formed as described. on the other hand a new purification method, which includes Sephadex G-200 filtration to purify the D:E complexes and separation of the D and E fragments by a 16 hrs. preparative isoelectric focussing. The latter step gives a complete separation of D (fragments) (pH = 6.5) and E fragments (at pH = 4.5) without any overlap, thus allowing a nearly 100% recovery in this step. The overall recoveries are around 75% of the theoretical values. These recoveries are superior to those of existing procedures. Moreover the conditions of this purification procedure are very mild and probably do not affect the native configuration of the products. Amino-terminal amino acids of human Dcate, D EGTA and D-dimer are identical i.e. val, asx and ser. in the ratgly, asx and ser were found. E 1% for rat Dcate=17-8 for rat D EGTA=16.2 and for rat D- dimer=l8.3. for the corresponding human fragments, these values were all 20.0 ± 0.2.

scholarly journals An open source fast fluid dynamics model for data center thermal management

2021 ◽  
Vol 230 ◽  
pp. 110599
Author(s):  
Xu Han ◽  
Wei Tian ◽  
Jim VanGilder ◽  
Wangda Zuo ◽  
Cary Faulkner
Keyword(s):  
Fluid Dynamics ◽  
Open Source ◽  
Thermal Management ◽  
Data Center ◽  
Dynamics Model
Sign in / Sign up

Export Citation Format

Share Document