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The particle Reynolds number is important in determining the fall velocity of a particle. When the particle Reynolds number indicates laminar flow, Stokes' law can be used to calculate its fall velocity or settling velocity. When the particle Reynolds number indicates turbulent flow, a turbulent drag law must be constructed to model the ...
The main parameter characterizing transition is the Reynolds number. Transition is often described as a process proceeding through a series of stages. Transitional flow can refer to transition in either direction, that is laminar–turbulent transitional or turbulent–laminar transitional flow.
The dimensionless Reynolds number is an important parameter in the equations that describe whether fully developed flow conditions lead to laminar or turbulent flow. The Reynolds number is the ratio of the inertial force to the shearing force of the fluid: how fast the fluid is moving relative to how viscous it is, irrespective of the scale of ...
In Poiseuille flow, for example, turbulence can first be sustained if the Reynolds number is larger than a critical value of about 2040; [25] moreover, the turbulence is generally interspersed with laminar flow until a larger Reynolds number of about 4000.
It is a function of Reynolds number of the flow. In case of laminar flow, this length is given by: , = [2] where is the Reynolds number and is the diameter of the pipe. But in the case of turbulent flow,
A turbulent flow in a fluid is defined by the critical Reynolds number, for a closed pipe this works out to approximately R e c ≈ 2000. {\displaystyle \mathrm {Re} _{\text{c}}\approx 2000.} In terms of the critical Reynolds number, the critical velocity is represented as
Dimensionless numbers (or characteristic numbers) have an important role in analyzing the behavior of fluids and their flow as well as in other transport phenomena. [1] They include the Reynolds and the Mach numbers, which describe as ratios the relative magnitude of fluid and physical system characteristics, such as density, viscosity, speed of sound, and flow speed.
A secondary influence is the Reynolds number. For a given adverse / distribution, the separation resistance of a turbulent boundary layer increases slightly with increasing Reynolds number. In contrast, the separation resistance of a laminar boundary layer is independent of Reynolds number — a somewhat counterintuitive fact.