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In thermodynamics, thermal stability describes the stability of a water body and its resistance to mixing. [1] It is the amount of work needed to transform the water to a uniform water density . The Schmidt stability "S" is commonly measured in joules per square meter (J/m 2 ).
Bifurcation theory is a useful way to study the stability of a given flow, with the changes that occur in the structure of a given system. Hydrodynamic stability is a series of differential equations and their solutions. A bifurcation occurs when a small change in the parameters of the system causes a qualitative change in its behavior,. [1]
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.
Values of thermal conductivities for various materials are listed in the list of thermal conductivities. As mentioned earlier in the article the convection heat transfer coefficient for each stream depends on the type of fluid, flow properties and temperature properties. Some typical heat transfer coefficients include: Air - h = 10 to 100 W/(m 2 K)
Thermal radiation is neglected, and body forces due to gravity are considered (unless said otherwise). In addition, for this type of flow, the next discussion highlights the hierarchy of flow equations solved with CFD. Note that some of the following equations could be derived in more than one way.
The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially parallel flow, counter current, and cross-flow exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). Alternatively, this method is useful for determining the expected heat ...
The thermal boundary layer thickness, , is the distance across a boundary layer from the wall to a point where the flow temperature has essentially reached the 'free stream' temperature, . This distance is defined normal to the wall in the y {\displaystyle y} -direction.
The lower the position of a metal's line in the Ellingham diagram, the greater is the stability of its oxide. For example, the line for Al (oxidation of aluminium) is found to be below that for Fe (formation of Fe 2 O 3) meaning that aluminium oxide is more stable than iron(III) oxide. Stability of metallic oxides decreases with increase in ...