What is the meaning of turbulence in physics?
turbulence, In fluid mechanics, a flow condition (see turbulent flow) in which local speed and pressure change unpredictably as an average flow is maintained. Common examples are wind and water swirling around obstructions, or fast flow (Reynolds number greater than 2,100) of any sort.
What is meant by turbulence flow?
turbulent flow, type of fluid (gas or liquid) flow in which the fluid undergoes irregular fluctuations, or mixing, in contrast to laminar flow, in which the fluid moves in smooth paths or layers. In turbulent flow the speed of the fluid at a point is continuously undergoing changes in both magnitude and direction.
What is a turbulent effect?
A turbulent flow can be caused by (too many) restrictions in an installation, such as valves or adapters, in combination with a high velocity of the used fluid. This effect is known as ‘turbulence effect’. In every restriction, the flow has been disrupted and the speed of the gas will change.
What is turbulence in biology?
turbulence. (Science: radiobiology) violent macroscopic fluctuations which can develop under certain conditions in fluids and plasmas and which usually result in the rapid transfer of energy through the medium.
What causes turbulence physics?
Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid’s viscosity. For this reason turbulence is commonly realized in low viscosity fluids.
What is meant by turbulence How does it affect the flow properties?
In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, exchanging energy, as a result drag increases due to friction effects. The level of turbulence has significant impact on the stability of boundary and shear layers.
What is turbulence intensity?
Turbulence intensity is defined as the ratio of standard deviation of fluctuating wind velocity to the mean wind speed, and it represents the intensity of wind velocity fluctuation.
What causes turbulence?
Friction between the air and the ground, especially irregular terrain and man-made obstacles, causes eddies and therefore turbulence in the lower levels. The intensity of this eddy motion depends on the strength of the surface wind, the nature of the surface and the stability of the air.
Can turbulence be explained?
On the physical side, turbulence happens when a smooth fluid flow starts to split into smaller eddies and vortices. These swirls then break into smaller swirls, with those swirls begetting ever-smaller whorls, an unpredictable cascade that dissipates the energy from the original smooth stream.
How does turbulence affect pressure?
When plotting a pressure-flow relationship (see figure to right), turbulence increases the perfusion pressure required to drive a given flow. Alternatively, at a given perfusion pressure, turbulence leads to a decrease in flow.
When can turbulence effect occur?
Maximum turbulence usually occurs near the mid-level of the storm, between 12,000 and 20,000 feet and is most severe in clouds of the greatest vertical development.
What caused turbulence?
Turbulence is caused when an airplane flies through waves of air that are irregular or violent, which cause the aircraft to bounce around yawing, pitching, or rolling.
How do solid particles affect the turbulence of carrier fluid?
The interaction between solid particles and the turbulence of the carrier fluid is considered. Theoretical considerations suggest that particles with low Reynolds number cause suppression of the turbulence, while particles with higher Reynolds number cause enhancement of turbulence due to wake shedding.
Does particle size affect turbulence intensity?
For example, Zisselmar & Molerus (1979) found that, for a given particle size, the turbulence intensity at the centerline was reduced; but, close to the wall the turbulence intensity was increased for certain values of particle concentration.
Do particles with high particle Reynolds number increase turbulence?
Particles with high particle Reynolds number (based on relative velocity and particle size), larger than about 400, tend to enhance the turbulence-most likely due to vortex shedding. Additional experimental data are needed to quantify this effect.
How do you calculate the intensity of turbulence?
The intensity of turbulence (Tu = u’z/uD, where uD is the velocity at the nozzle) at the jet axis, when the jet was laden with particles of three sizes, is depicted in figure 7. The effect of the 170 ,um particles is to decrease the intensity of turbulence.