Comsol中Absolute Pressure的解释
自己将Comsol中Abolute Pressure的说明翻译了一下，以给需要的朋友，如有翻译不当之处，敬请指正。
Enter the Absolute pressure pA (SI unit: Pa). The default is atmosphere pressure, 1 atm (101,325 Pa).
输入绝对压力pA（SI单位：Pa）。默认值是大气压，1 atm (101,325 Pa)。
This section controls both the variable as well as any property value (reference pressures) used when solving for pressure. There are usually two ways of calculating the pressure when describing fluid flow, and mass and heat transfer. Solve for the absolute pressure or a pressure (often denoted gauge pressure) that relates back to the absolute pressure through a reference pressure.
这部分控制求解压力时的变量和任何属性值（参考压力）。当描述流体流动、质量和传热时压力的计算通常有两种方法：求解绝对压力或表压力，表压力通过参考压力回归到绝对压力。
注：如果使用表压力，则在接口中输入的压力为表压力（绝对压力-参考压力）。
Using one or the other usually depends on the system and the equations being solved for. For example, in a straight incompressible flow problem, the pressure drop over the modeled domain is probably many orders of magnitude less than atmospheric pressure, which, if included, reduces the chances for stability and convergence during the solving process for this variable. In other cases, the absolute pressure may be required to be solved for, such as where pressure is a part of an expression for gas volume or diffusion coefficients.
使用绝对压力或者表压力取决于求解的系统和方程。例如，在一个直接不可压缩流问题中，在模拟域的压力下降可能比大气压小许多数量级，在这种情况下，如果包括，将降低在求解这个变量的过程中的稳定性和收敛性（这种情况下求解表压力）。在其他情况下，可能需要求解绝对压力，例如当压力是气体体积或扩散系数的表达式的一部分。
The absolute pressure model input is controlled by both a drop-down list and a check box within this section. Use the User defined option to manually define the absolute pressure in a system. This is the default setting.
绝对压力的模型输入是由一个下拉列表和一个复选框来控制。使用用户定义的选项来手动定义在一个系统中的绝对压力。这是默认设置。
The pressure variables solved for by a fluid-flow interface can also be used, which is selected from the list as, for example, Pressure spf/fp. Selecting a pressure variable also activates a check box for defining the reference pressure, where 1[atm] (1 atmosphere) is the default value. This makes it possible to use a system-based (gauge) pressure as the pressure variable while automatically including the reference pressure in places where it is required, such as for gas flow governed by the gas law. While this check box maintains control over the pressure variable and instances where absolute pressure is required within this respective physics interface, it may not with physics interfaces that being coupled to. In such models, check the coupling between any interfaces using the same variable.
也可以使用由一个流体流动接口求解的压力变量，它从列表中选择，例如，压力 spf/fp。选择一个压力变量也激活一个定义参考压力的复选框，其默认值是一个大气压。这使得可以使用一个基于系统的压力（表压力）作为压力变量，同时在需要的地方自动包含参考压力，例如对于由气体定律支配的气流。虽然此复选框保持对需要绝对压力的物理接口中的压力变量和实例的控制，它可能没有伴随耦合的物理接口。在这种模型中，使用相同的变量检查物理接口之间的耦合。