Search results for "Fluid dynamics"
showing 10 items of 1005 documents
Temperature and pressure dependence of the viscosities of perfluoropolyether fluids
1987
The viscosities of two structurally different perfluoropolyether fluids were determined at a series of temperatures and pressures, from 25 to 100°C and from 1 to 1000 bars. Flow activation energies and volumes as well as their temperature and pressure coefficients were derived. An attempt was made to relate measured and derived quantities to the compound structures.
Bubble motion through non-crimp fabrics during composites manufacturing
2008
Bubbles motion through interbundle channels in biaxial non-crimp fabrics is modelled. The scenario is that formed bubbles move with the resin through these channels and are trapped if the channels become too narrow. By usage of a permeability network model, existing criteria on bubble deformation and a variety of analytical and probabilistic methods it is found that the paths of the bubbles depend significantly on the position of the threads keeping the fabric together and the number of fibres crossing the interbundle channels. Another result is that the pressure difference over a trapped bubble increases with 50% in a 3D geometry possible helping the bubble to escape. A third result is tha…
Studies on Instabilities and Patterns in Evaporating Liquids at Reduced Pressure and/or Microwave Irradiation
1990
This paper summarizes our recent experimental and theoretical work on the instabilities in liquids and at interfaces which form during evaporation at reduced pressure and/or microwave irradiation. We have observed a variety of patterns (Benard rolls, Marangoni waves, Hickman interface deformations) which depend on the value of the reduced pressure and the power of the incident beam.
Induction mechanisms in a von Kármán swirling flow of liquid Gallium
2004
Using in situ magnetic field measurements, we study the induction mechanisms in a swirling flow of liquid Gallium generated inside a cylinder, in the gap between two coaxial rotating discs. The von Kármán flow generated in this manner has both helicity and differential rotation. Magnetic Reynolds numbers Rm up to 7 (based on the disc rim speed) are generated. We study the magnetic induction when an external field is applied successively along the axis, in the azimuthal direction or tranverse to the axis of rotation. In the first two cases, both the flow and the magnetic field are axisymmetric, and an effective mechanism of conversion from poloidal to toroidal field exists but, in agreement …
M2_Microfluidics_for_CNT
2018
Droplet production in flow-focusing microfluidic device. The droplets are cut off from the water phase flow by pressure of oil from the side channels. The movement of the droplets proves laminar flow in the device.
M4_Microfluidics_for_CNT
2018
Size and frequency of the droplets produced in T-junction as a function of continuous and disperse phase pressure ratio.
M7_Microfluidics_for_CNT
2018
A comparation of two designs of a droplet trap. While the droplet exchange is mediated by direct droplet contact in the symmetric design, a short continuous phase plug mediated the droplet exchange in the asymmetric design.
M3_Microfluidics_for_CNT
2018
Droplet production in T-junction microfluidic device. The droplets are cut off from the water phase flow by pressure of oil. The droplets confined in the channel proceed at the same speed as the continuous phase.
M1_Microfluidics_for_CNT
2018
High-frequency droplet production in step-emulsification microfluidic device. The abrupt change in channel cross section causes creation of the droplets. The closely-packed droplets automatically order in hexagonal pattern.
Relative importance of second-order terms in relativistic dissipative fluid dynamics
2014
[Introduction] In Denicol et al. [Phys. Rev. D 85 , 114047 (2012)], the equations of motion of relativistic dissipative fluid dynamics were derived from the relativistic Boltzmann equation. These equations contain a multitude of terms of second order in the Knudsen number, in the inverse Reynolds number, or their product. Terms of second order in the Knudsen number give rise to nonhyperbolic (and thus acausal) behavior and must be neglected in (numerical) solutions of relativistic dissipative fluid dynamics. The coefficients of the terms which are of the order of the product of Knudsen and inverse Reynolds numbers have been explicitly computed in the above reference, in the limit of a massl…