conservation of mass

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Related to Mass conservation: law of conservation of mass, Continuity equation

Conservation of mass

The notion that mass, or matter, can be neither created nor destroyed. According to conservation of mass, reactions and interactions which change the properties of substances leave unchanged their total mass; for instance, when charcoal burns, the mass of all of the products of combustion, such as ashes, soot, and gases, equals the original mass of charcoal and the oxygen with which it reacted.

The special theory of relativity of Albert Einstein, which has been verified by experiment, has shown, however, that the mass of a body changes as the energy possessed by the body changes. Such changes in mass are too small to be detected except in subatomic phenomena. Furthermore, matter may be created, for instance, by the materialization of a photon (quantum of electromagnetic energy) into an electron-positron pair; or it may be destroyed, by the annihilation of this pair of elementary particles to produce a pair of photons. See Electron-positron pair production, Relativity

conservation of mass

[‚kän·sər′vā·shən əv ′mas]
The notion that mass can neither be created nor destroyed; it is violated by many microscopic phenomena.
References in periodicals archive ?
The likely reason is its poor mass conservation compared to the other solutions: at T = 40,
As expected, mass conservation by each of the solutions was also very good:
For the purpose of maintaining the global mass conservation, the sink function [F.
a](x) should be also applied to the air/melt front equation, because the mass conservation of air must be also satisfied:
If system variables are defined in terms of node pressures, here collected into a single vector,{p}, then the system equations may be formed by imposing mass conservation at each node of the system idealization.
Finally, system variables may be defined in terms of the flow-element mass airflow rates and collected into a single vector,{m}, and mass conservation coupled with loop consistency may be imposed to form the system equations.
Concerns are often raised about global mass conservation in the pseudo-concentration method for interface tracking.
Attempts to improve mass conservation have led to a number of techniques reported in the literature.
The final sizes of bubbles were predicted numerically from a model by considering diffusion of gas into the bubble, fluid flow outside the bubble in radial direction, reaction kinetics for curing of polyurethane, mass conservation, energy conservation, continuity of fluid, and Henry's law for solubility.
Before presenting the pure finite-element methodology for the solution of the pressure field and the fill factors, an alternate form of conservation mass equation based on the resin mass conservation involving the time derivative of the fill factor is considered and is presented next.
The flow front is supposed to be fiat, and its kinematics is largely determined by the mass conservation rather than the momentum conservation.
The shortening Control Volume (CV) model based on the mass conservation principle is then used to establish the relationship between the velocities of air-water fronts moving rectilinearly along the horizontal pipeline.