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In atmospheric science, several different expressions for the Richardson number are commonly used: the flux Richardson number (which is fundamental), the gradient Richardson number, and the bulk Richardson number. The flux Richardson number is the ratio of buoyant production (or suppression) of turbulence kinetic energy to the production of ...
The Bulk Richardson Number (BRN) is a dimensionless number relating vertical stability and vertical wind shear (generally, stability divided by shear). It represents the ratio of thermally-produced turbulence and turbulence generated by vertical shear. Practically, its value determines whether convection is free or forced.
The Bulk Richardson Number (BRN) is an approximation of the Gradient Richardson number. [1] The BRN is a dimensionless ratio in meteorology related to the consumption of turbulence divided by the shear production (the generation of turbulence kinetic energy caused by wind shear) of turbulence.
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.
The relative effect of buoyancy on mixed convection can be expressed through the Richardson number: R i = G r R e 2 {\displaystyle \mathrm {Ri} ={\frac {\mathrm {Gr} }{\mathrm {Re} ^{2}}}} The respective length scales for each dimensionless number must be chosen depending on the problem, e.g. a vertical length for the Grashof number and a ...
The most important feature of baroclinic instability is that it exists even in the situation of rapid rotation (small Rossby number) and strong stable stratification (large Richardson's number) typically observed in the atmosphere. [citation needed] The energy source for baroclinic instability is the potential energy in the environmental flow.
Usually, there is a transition from laminar to turbulent as the plume moves away from its source. This phenomenon can be clearly seen in the rising column of smoke from a cigarette. When high accuracy is required, computational fluid dynamics (CFD) can be employed to simulate plumes, but the results can be sensitive to the turbulence model chosen.
The most generally used dimensionless number would be the Richardson number and Rayleigh number. The mathematics of the flow is therefore simpler because the density ratio ρ 1 / ρ 2 , a dimensionless number , does not affect the flow; the Boussinesq approximation states that it may be assumed to be exactly one.