a condition that is required to be satisfied at all or part of the boundary of a region in which a set of differential equations is to be solved.
Example: One consequence of this expression, and of the BOUNDARY CONDITIONS, is that the string can only support whole numbers of half wavelengths.
es: Condiciones de borde
Emissivity
Noun
Emissivity, formerly called emittance, is the proportion of thermal radiation emitted by a surface or object due to its temperature.
Example: Polished stainless steel, has an emissivity of approximately 0.1 and therefore emits only one tenth the amount of energy of a blackbody at the same temperature.
es: Emisividad
Energy balance
Noun
The net change (increase or decrease) in the total energy of the system during a process is equal to the difference between the total energy entering and the total energy leaving the system during that process.
Example: Data on 14 July pm for sheltered crops were wrong, as they cannot be balanced in the ENERGY BALANCE equation: (G can be ignored because of it was always less than 10 Wm -2 .) As data from the opened crops can be balanced by the ENERGY BALANCE equation, Rn = 502 Wm -2 was very likely to be correct.
es: Balance de energía
Heat conduction equation
Noun
The heat conduction equation is a partial differential equation that describes the distribution of heat (or the temperature fields) in a given body over time. Detailed knowledge of the temperature field is very important in thermal conduction through materials.
Example: The ice, when put in a cup of boiling water, melts completely.
es: Ecuación de conducción de calor
Heat flux
Noun
Heat flux or thermal flux, sometimes also known as heat flux density or heat flow rate intensity is a flux of energy per unit area per unit time. In SI, its units are watts per square meter.
Example: The mast recorded measurements every five minutes of air temperature, relative humidity, wind speed and direction, solar and net radiation, ground HEAT FLUX, and potential gradient.
es: Flujo de calor
Insulation
Noun
the action of insulating something.
Example: keep your home warmer through insulation
es: Aislamiento
Internal energy
Noun
The internal energy of a thermodynamic system is the energy contained within it. It is the energy necessary to create or prepare the system in any given internal state. It does not include the kinetic energy of motion of the system as a whole, nor the potential energy of the system as a whole due to external force fields, including the energy of displacement of the surroundings of the system. It keeps account of the gains and losses of energy of the system that are due to changes in its internal state.
Example: The change in INTERNAL ENERGY (U) of the system is equal to the heat added (Q).
This means the system does work on its surroundings, and the change in INTERNAL ENERGY (U) is equal to the heat added (Q) plus the work done (W).
es: Energía interna
Isotropic system
Noun
Isotropic systems are uniform regardless of direction
Example: Radiation may be isotropic when the the observed intensity is the same in all directions from the source.
es: Sistema isotrópico
Specific heat
Noun
The quantity of heat required to raise the temperature of one gram of a substance by one Celsius degree. The units of specific heat are usually calories or joules per gram per Celsius degree.
Example: The heat required to raise the temperature of 1 kg of water by 1 K is 4184 joules, so the specific heat capacity of water is 4184 J⋅kg⋅K.
es: Calor específico
Temperature
Noun
the degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch.
Example: he was running a temperature
es: Temperatura
Temperature gradient
Noun
In the Earth's atmosphere there is a variable thermal gradient as a function of altitude with respect to sea level.
es: Gradiente de temperatura
Thermal conductivity
Noun
The thermal conductivity (k) is a measure of a material’s ability to conduct heat.
Example: Walking on bathroom tile in winter is annoying since it feels so much colder than the carpet. This is interesting, since the carpet and tile are usually both at the same temperature. Tile and stone conduct heat more rapidly than carpet and fabrics, so tile and stone feel colder in winter since they transfer heat out of your foot faster than the carpet does.
es: Conductividad térmica
Thermal diffusivity
Noun
Thermal diffusivity is the thermal conductivity divided by density and specific heat capacity at constant pressure. It measures the ability of a material to conduct thermal energy relative to its ability to store thermal energy. High diffusivity means heat transfers rapidly.
Example: Initial spore load: The severity of the process depends on the initial spore load; good factory hygiene keeps this low. 8.Thermophysical properties : The THERMAL DIFFUSIVITY is the controlling factor.
es: Difusividad térmica
Thermal energy
Noun
Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. Is produced when a rise in temperature causes atoms and molecules to move faster and collide with each other.
Example: The warmth from the sun.
es: Energía térmica
Thermal symmetry
Noun
A heat transfer problem that is symmetric about a plane, line, or point is said to have thermal symmetry about that plane, line, or point. The thermal symmetry boundary condition is a mathematical expression of this thermal symmetry.
Example: The two surfaces of a large hot plate of thickness L suspended vertically in air will be subjected to the same thermal conditions, and thus the temperature distribution will be symmetrical (i.e. in one half of the plate will be the same temperature profile as that in the other half).
