液压油 Oil

Openhydraulics 中的液压油位于Fluids 包下面,液压油是所有液压组件的基础。在OpenHydraulics 中,预设了两种液压油模型,二者均以PartialFluid 为基类。

PartialFluid

此类型不能独立使用,类似于一般编程语言中的抽象类:

classDiagram  
    class PartialFluid {        
       + constant SI.Temperature Toperating = 293.15 "工作环境温度";
       + constant SI.Temperature T0 =273.15 "参考温度0 ℃";
       + constant SI.AbsolutePressure p0 = 101325 "标准大气压";

       + replaceable function density(AbsolutePressure p)  "计算密度"
       + replaceable function dynamicViscosity(AbsolutePressure p)  "计算粘度"
       + replaceable function approxBulkModulus(AbsolutePressure p)  "体积模量,近似计算中才会用到"
    }

GenericOilSimple

简单的液压油模型,其中

  • 密度公式:

d=870+5×107×(pp0)d = 870 + 5 \times 10^{-7} \times (p-p_0)

  • 粘度公式:

η=0.036\eta = 0.036

GenericOil

通用液压油,较为精确,其中

  • 密度公式:

{K00=8.4×109K0prime=10.9βK=0.0058aV=7.7×104d0=870K0=K00×eβK×Toperatingd=d0/(1+aV(ToperatingT0))/(1ln(1+p(1+K0prime)/K0)/(1+K0prime))\left\{\begin{array}{lll} K0_{0} = 8.4 \times 10^9 \\ K0_{prime} = 10.9 \\ \beta_{K} = 0.0058 \\ a_V = 7.7 \times 10^{-4} \\ d_0 = 870 \\ K0 = K0_0 \times e^{-\beta_K \times T_{operating}} \\ d = d0/(1+a_V(T_{operating}-T_0))/ (1-ln(1+p(1+K0_{prime})/K0)/(1+K0_{prime})) \end{array} \right.

  • 粘度公式:

{A=9.32B=3.65η=(1010(ABlog(Toperating))0.7)density(p)106\left\{\begin{array}{lll} A = 9.32 \\ B = 3.65 \\ \eta = (10^{10^{(A-B*log(T_{operating}))}}-0.7)*density(p)*10^{-6} \end{array} \right.

OpenHydraulics.Circuits.Environment

在仿真时还需要设置工作环境,一般默认环境大气压为一个标准大气压,温度为288.15K。在每个液压组件模型中,都会包含两个outer 变量:oilenvironment


2022-12-28 山东