Related Experiment Video
Updated: Jun 14, 2026
09:58
Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp
Published on: February 3, 2014
Turbulent spot evolution in spatially invariant boundary layers.
1Linné Flow Centre, KTH Mechanics, SE-10044 Stockholm, Sweden.
Summary
This study reveals a natural stabilization mechanism for turbulent spots in boundary layer flows. The origin of these spots significantly impacts their streamwise evolution, with Reynolds number effects also observed.
Area of Science:
- Fluid dynamics
- Turbulence transition
- Boundary layer theory
Background:
- Predicting turbulence transition is crucial for industrial fluid dynamic design.
- Turbulent spots play a key role in the late stages of transition.
- Understanding spot evolution is essential for flow control and prediction.
Purpose of the Study:
- To investigate the late-stage transition scenarios where turbulent spots originate.
- To identify natural stabilizing mechanisms affecting turbulent spot growth rates.
- To examine the influence of turbulent spot origin and Reynolds number on streamwise evolution.
Main Methods:
- Conducted an idealized experimental study focusing on bypass transition scenarios.
- Analyzed the growth rate of turbulent spots.
- Investigated the history effect of turbulent spot origin on streamwise evolution.
- Examined Reynolds number effects on spot evolution in boundary layers.
Main Results:
- A natural stabilizing mechanism on turbulent spot growth rate was identified.
- A significant history effect of the turbulent spot origin on its streamwise evolution was observed.
- Experimental evidence on Reynolds number effects on spot evolution was provided.
Conclusions:
- The study elucidates a stabilizing mechanism in turbulent spot development.
- The origin of turbulent spots has a palpable impact on their evolution.
- Findings contribute to a deeper understanding of boundary layer transition phenomena.
More Related Videos
Related Concept Videos
01:18Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
01:24Turbulent Flow
Turbulent flow is characterized by unpredictable fluctuations in velocity and pressure, which result in a chaotic fluid movement distinct from the orderly patterns of laminar flow. While laminar flow is governed by smooth, parallel layers with minimal mixing, turbulent flow exhibits highly irregular, three-dimensional patterns. This behavior arises due to instabilities in the fluid's velocity profile, and amplifies as the flow velocity increases. Minor disturbances, known as turbulent spots,...
01:07Laminar and Turbulent Flow
Fluid dynamics is the study of fluids in motion. Velocity vectors are often used to illustrate fluid motion in applications like meteorology. For example, wind—the fluid motion of air in the atmosphere—can be represented by vectors indicating the speed and direction of the wind at any given point on a map. Another method for representing fluid motion is a streamline. A streamline represents the path of a small volume of fluid as it flows. When the flow pattern changes with time, the streamlines...
01:28Irrotational Flow
Irrotational flow is characterized by fluid motion where particles do not rotate around their axes, resulting in zero vorticity. For a flow to be irrotational, the curl of the velocity field must be zero. This imposes specific conditions on velocity gradients. For instance, to maintain zero rotation about the z-axis, the gradient condition:
01:30Bernoulli's Equation for Flow Along a Streamline
Bernoulli's equation relates the energy conservation in a fluid moving along a streamline. The equation applies to incompressible and inviscid fluids under steady flow. For such a flow, Newton's second law is applied to a small fluid element, which experiences forces due to pressure differences, gravity, and velocity variations. The force balance leads to the following form of Bernoulli's equation:
01:09Turbulent Flow: Problem Solving
Carbonation is a process used to dissolve carbon dioxide gas in a liquid, commonly used in the production of carbonated beverages. Achieving efficient carbonation requires careful control of temperature, pressure, and flow conditions. By adjusting these parameters, carbonation efficiency can be maximized, producing a higher concentration of CO2 in the liquid.
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures enhance...
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures enhance...