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The concept of potential temperature applies to any stratified fluid. It is most frequently used in the atmospheric sciences and oceanography. [2] The reason that it is used in both fields is that changes in pressure can result in warmer fluid residing under colder fluid – examples being dropping air temperature with altitude and increasing water temperature with depth in very deep ocean ...
In a distribution, full width at half maximum (FWHM) is the difference between the two values of the independent variable at which the dependent variable is equal to half of its maximum value. In other words, it is the width of a spectrum curve measured between those points on the y -axis which are half the maximum amplitude.
The Brunt–Väisälä frequency commonly appears in the thermodynamic equations for the atmosphere and in the structure of stars. Trajectory of a parcel of fluid displaced by 1m in an unstably stratified fluid of Brunt-Väisälä frequency N 2 = −1/ s 2 Oscillations of a parcel of fluid initially displaced by 1m in a stably stratified fluid ...
Taken together with the velocity potential, the stream function may be used to derive a complex potential. In other words, the stream function accounts for the solenoidal part of a two-dimensional Helmholtz decomposition, while the velocity potential accounts for the irrotational part.
If a fluid is compressible like air, the criterion for dynamic stability instead involves potential density, the density of the fluid at a fixed reference pressure. For an ideal gas (see gas laws), the stability criterion for an air column is that potential temperature increases monotonically with height.
Siméon Denis Poisson. Poisson's equation is an elliptic partial differential equation of broad utility in theoretical physics.For example, the solution to Poisson's equation is the potential field caused by a given electric charge or mass density distribution; with the potential field known, one can then calculate the corresponding electrostatic or gravitational (force) field.
where g is the gravitational acceleration, is the thermal expansion coefficient, T hot is the hot wall temperature, T ref is the reference temperature, L is the characteristic length, and V is the characteristic velocity. The Richardson number can also be expressed by using a combination of the Grashof number and Reynolds number,
A velocity potential is not unique. If ϕ is a velocity potential, then ϕ + f(t) is also a velocity potential for u, where f(t) is a scalar function of time and can be constant. Velocity potentials are unique up to a constant, or a function solely of the temporal variable. The Laplacian of a velocity potential is equal to the divergence of the ...