Modeling processes of the high-speed spinning of viscoelastic polymer melts allowing for the total force balance

1990 ◽  
Vol 22 (6) ◽  
pp. 378-382
Author(s):  
N. K. Zhiganov ◽  
V. I. Yankov ◽  
V. �. Geller
Keyword(s):  
High Speed ◽  
Polymer Melts ◽  
Modeling Processes ◽  
Force Balance ◽  
Total Force ◽  
Viscoelastic Polymer

scholarly journals Study on the Effect of Nanoparticle Used in Nano-Fluid Flooding on Droplet–Interface Electro-Coalescence

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1764
Author(s):  
Donghai Yang ◽  
Huayao Sun ◽  
Qing Chang ◽  
Yongxiang Sun ◽  
Limin He
Keyword(s):  
Interfacial Tension ◽  
Oil Recovery ◽  
Liquid Bridge ◽  
High Speed ◽  
Droplet Formation ◽  
Force Balance ◽  
Secondary Droplet ◽  
Droplet Deformation ◽  
Deformation Degree ◽  
Nano Fluid

Nano-fluid flooding is a new method capable of improving oil recovery; however, nanoparticles (NPs) significantly affect electric dehydration, which has rarely been investigated. The effect of silica (SiO2) NPs on the droplet–interface coalescence was investigated using a high-speed digital camera under an electric field. The droplet experienced a fall, coalescence, and secondary droplet formation. The results revealed that the oil–water interfacial tension and water conductivity changed because of the SiO2 NPs. The decrease of interfacial tension facilitated droplet deformation during the falling process. However, with the increase of particle concentration, the formed particle film inhibited the droplet deformation degree. Droplet and interface are connected by a liquid bridge during coalescence, and the NP concentration also resulted in the shape of this liquid bridge changing. The increase of NP concentration inhibited the horizontal contraction of the liquid bridge while promoting vertical collapse. As a result, it did not facilitate secondary droplet formation. Moreover, the droplet falling velocity decreased, while the rising velocity of the secondary droplet increased. Additionally, the inverse calculation of the force balance equation showed that the charge of the secondary droplet also increased. This is attributed to nanoparticle accumulation, which resulted in charge accumulation on the top of the droplet.

scholarly journals Shock Tube as an Impulsive Application Device

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Soumya Ranjan Nanda ◽  
Sumit Agarwal ◽  
Vinayak Kulkarni ◽  
Niranjan Sahoo
Keyword(s):  
Heat Transfer ◽  
Shock Tube ◽  
High Speed ◽  
Force Measurement ◽  
Peak Load ◽  
Wave Force ◽  
Impulsive Loading ◽  
Force Balance ◽  
Test Model ◽  
Impulse Facility

Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

Mechanical Model of Pelletization in the Impressing Roller System

2013 ◽  
Vol 732-733 ◽  
pp. 348-351
Author(s):  
Xiao Peng Huang ◽  
Fang Xin Wan ◽  
Jing Feng Wu
Keyword(s):  
Research Result ◽  
Reference Value ◽  
Force Balance ◽  
Total Force ◽  
Force Analysis ◽  
Forming Mechanism ◽  
Material Layer ◽  
Work Area ◽  
Function Relationship ◽  
Roller System

By the force analysis of alfalfa grass powder material layer in work area of circular mould pelletizing system, grass pellet briquetting mechanism when alfalfa grass powder pass work area was explained, function relationship between the thickness of material layer and the circular mould angle was established, force balance equation of material layer differentiation unit under the general conditions was deduced, and the total force of material layer applied by circular mould was obtained. Research result has practical meaning for guiding the process test of grass pellet product and optimizing product structure, and has a certain theoretical reference value for in-depth revealing granulating forming mechanism of hoop standard granulator.

Effect of Draw Furnace Geometry on High Speed Optical Fiber Manufacturing

2000 ◽  
Author(s):  
Xu Cheng ◽  
Yogesh Jaluria
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Optimal Design ◽  
Optical Fiber ◽  
High Speed ◽  
Graphite Furnace ◽  
Large Diameter ◽  
High Volume ◽  
Force Balance ◽  
Zonal Method

Abstract The motivation of manufacturers to pursue higher productivity and low costs in the fabrication of optical fibers requires large diameter silica-based preforms drawn into fiber at very high speed. An optimal design of the draw furnace is particularly desirable to meet the need of high-volume production in the optical fiber industry. This paper investigates optical fiber drawing at high draw speeds in a cylindrincal graphite furnace. A conjugate problem involving the glass and the purge gases is considered. The transport in the two regions is coupled through the boundary conditions at the free glass surface. The zonal method is used to model the radiative heat transfer in the glass. The neck-down profile of the preform at steady state is determined by a force balance, using an iterative numerical scheme. Thermally induced defects are also considered. To emphasize the effects of draw furnace geometry, the diameters of the preform and the fiber are kept fixed at 5 cm and 125 μm, respectively. The length and the diameter of the furnace are changed. For the purposes of comparison, a wide domain of draw speeds, ranging from 5 m/s to 20 m/s, is considered, and the form of the temperature distribution at the furnace surface is kept unchanged. The dependence of the preform/fiber characteristics, such as neckdown profile, velocity distribution and lag, temperature distribution and lag, heat transfer coefficent, defect concentration, and draw tension, on the furnace geometry is determined. Based on these numerical results, an optimal design of the draw furnace can be developed.

Network Theoretic Approach to Atomistic Material Modeling Using Spectral Sparsification

2017 ◽  
Author(s):  
Peter C. Woerner ◽  
Aditya G. Nair ◽  
Kunihiko Taira ◽  
William S. Oates
Keyword(s):  
Coulomb Potential ◽  
Network Theory ◽  
Force Balance ◽  
Total Force ◽  
Theoretic Approach ◽  
Lennard Jones Potential ◽  
Jones Potential ◽  
Lennard Jones ◽  
Internal Forces ◽  
Molecular Forces

Network theory is used to formulate an atomistic material network. Spectral sparsification is applied to the network as a method for approximating the interatomic forces. Local molecular forces and the total force balance is quantified when the internal forces are approximated. In particular, we compare spectral sparsification to conventional thresholding (radial cut-off distance) of molecular forces for a Lennard-Jones potential and a Coulomb potential. The spectral sparsification for the Lennard-Jones potential yields comparable results while spectral sparsification of the Coulomb potential outperforms the thresholding approach. The results show promising opportunities which may accelerate molecular simulations containing long-range electrical interactions which are relevant to many multifunctional materials.

The Influence of Partial Force Balancing on the Shaking Moments, Contact Forces, and Precision of a Delta Robot-Like Manipulator in a Compliant Frame

2018 ◽  
Author(s):  
Jan J. de Jong ◽  
J. P. Meijaard ◽  
Volkert van der Wijk
Keyword(s):  
High Speed ◽  
Contact Forces ◽  
Force Balance ◽  
Dynamic Loads ◽  
Accuracy Improvement ◽  
End Effector ◽  
Pick And Place ◽  
Delta Robot ◽  
Full Force ◽  
Typical Design

For the Delta robot, a high-speed parallel pick-and-place manipulator, base vibrations are a significant problem. Especially since the Delta robot is suspended above its workpiece, it requires a large, stiff, and heavy base frame for fast and accurate motions. Dynamic balancing of the shaking forces and the shaking moments is a known technique to reduce the dynamic loads on the base frame and to the surroundings. In this paper it is investigated how solely with partial force balancing, dynamic loads and pick-and-place accuracy of a Delta robot-like manipulator can be improved, considering also the compliance of the base frame. This is done since partial force balance solutions can be implemented relatively simply in the current Delta robot designs, whereas full force and moment balance solutions are complex to apply in practice. Numerical simulations with a representative planar model of a Delta robot-like manipulator with a compliant base frame show that with an increasing amount of force balance the shaking moments increase up to 16% for full force balance. The floor contact forces first reduce and then increase with increasing force balance. With 43% force balance the floor contact forces are minimal, giving a 63% reduction. The end-effector accuracy slightly improves with increasing force balance until full force balance yields a 31% accuracy improvement. A further increase of the force (over) balance shows a 59% improvement of end-effector accuracy for 350% force balance. These effects are mainly due to the typical design of the Delta robot base frame and the way the robot is mounted to it.

Sensitivity Analysis and Parameter Optimization of a Hydrodynamic Model for the Aeration Chamber in a Water-Lifting Aerator

2013 ◽  
Vol 663 ◽  
pp. 888-893
Author(s):  
Xin Sun ◽  
Fei Fei Duan ◽  
Ting Lin Huang
Keyword(s):  
Sensitivity Analysis ◽  
Hydrodynamic Model ◽  
Flow Resistance ◽  
Water Velocity ◽  
Force Balance ◽  
Model Parameters ◽  
Total Force ◽  
Two Phase ◽  
Optimized Model ◽  
Resistance Coefficients

A one-dimensional hydrodynamic model for the aeration chamber in the water-lifting aerator was developed on the basis of the total force balance between the driving force and flow resistance acting on the gas-liquid two-phase flow. Water velocity in the aeration chamber was predicted under different combinations of flow resistance coefficients at the top (KT) and the entrance and exit (KE), the results of sensitivity analysis showed that both KT and KE have significant effect on the predicted water velocity and gas holdup in the riser of the aeration chamber. Taking the water velocity as the main objective, flow resistance coefficients of KT and KE were optimized as and , where Ulr is the superficial water velocity. Using optimized model parameters, the water velocities were well predicted within ±7% of the measured ones respectively.

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