Related Experiment Video
Updated: Mar 30, 2026
07:08
Film Control to Study Contributions of Waves to Droplet Impact Dynamics on Thin Flowing Liquid Films
Published on: August 18, 2018
7.9K
Gravity-driven soap film dynamics in subcritical regimes.
M I Auliel1, F Castro1, R Sosa1
1Laboratory of Fluid Dynamics, Facultad de Ingeniería, Universidad de Buenos Aires and CONICET, Paseo Colón 850, C1063ACV Buenos Aires, Argentina.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 14, 2015
Summary
This study analyzes vertical soap film dynamics using asymptotic expansions. We found that under specific conditions, the flow behaves as a 2D system where film thickness changes correlate with velocity gradients.
Area of Science:
- Fluid Dynamics
- Nonlinear Dynamics
- Surface Science
Background:
- Soap film dynamics are crucial in various scientific and industrial applications.
- Understanding the behavior of thin films under different flow regimes is essential for predicting their stability and evolution.
- Previous studies have explored soap film dynamics, but a detailed analysis in subcritical regimes with specific elastic Mach numbers is needed.
Purpose of the Study:
- To analyze the dynamics of vertical soap films in subcritical regimes.
- To investigate the flow behavior using asymptotic expansions and nondimensional numbers.
- To identify the relationship between film thickness changes and velocity gradients.
Main Methods:
- Application of asymptotic expansion techniques to model soap film dynamics.
- Analysis of vertical soap film tunnels operating in subcritical regimes.
- Characterization of flow using relevant nondimensional numbers, including elastic Mach numbers (M(e)).
Main Results:
- The flow in vertical soap film tunnels under subcritical regimes behaves as a two-dimensional (2D) divergence-free flow with variable mass density.
- When the soap film dynamics approximate a 2D flow with nearly constant mass density, specific regions are identified.
- These regions, where the second invariant of the velocity gradient is non-null, directly correspond to areas with a non-negligible rate of change in film thickness.
Conclusions:
- The study provides a detailed analysis of soap film dynamics in a specific regime.
- The findings highlight the connection between velocity gradients and film thickness variations in 2D flows.
- This research contributes to a better understanding of thin film behavior and its underlying physical mechanisms.
Related Concept Videos
01:13Excess Pressure Inside a Drop and a Bubble
3.8K
The shape of a small drop of liquid can be considered spherical, neglecting the effect of gravity. This drop can further be considered as two equal hemispherical drops put together due to surface tension. The forces acting on the spherical drop are due to the pressure of the liquid inside the drop, the pressure due to air outside the drop, and the force due to the surface tension acting on the two hemispherical drops.
3.8K
03:22Colloids
22.0K
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...
22.0K
03:00Solubility
22.8K
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
22.8K
01:22Surface Tension of Fluid
1.9K
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
1.9K
01:23Factors Affecting Dissolution: Particle Size and Effective Surface Area
2.0K
Dissolution kinetics, an essential aspect of oral drug delivery, is significantly influenced by the drug's particle size. According to the Noyes-Whitney dissolution model, the dissolution rate correlates directly with the drug's surface area. The larger the surface area, the higher the drug's solubility in water, leading to a faster drug dissolution rate. Reducing particle size increases the effective surface area, enhancing the dissolution process. Micronization and nanosizing are...
2.0K
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
908
Various dissolution theories provide insight into the factors that influence the dissolution rate. Danckwerts' Model suggests that turbulence, rather than a stagnant layer, characterizes the dissolution medium at the solid-liquid interface. In this model, the agitated solvent contains macroscopic packets that move to the interface via eddy currents, facilitating the absorption and delivery of the drug to the bulk solution. The regular replenishment of solvent packets maintains the...
908