Constant Volume

Chamber to model compressible fluid

 Description The Constant Volume component models fluid compressibility and contains a mixture of liquid and a small amount of non-dissolved gas, which is used in an approximate model of cavitation. The fluid bulk modulus, $K$, and atmospheric pressure, ${p}_{\mathrm{atm}}$ come from a Fluid Properties record at the same or higher level in the overall model.
 Equations $E=\left\{\begin{array}{cc}K& \mathrm{\alpha }=0\\ \frac{\frac{1}{\mathrm{\alpha }}+\frac{1}{\mathrm{\gamma }}}{\frac{1}{\mathrm{\alpha }K}+\frac{1}{k\mathrm{\gamma }\mathrm{\beta }{p}_{\mathrm{atm}}}}& \mathrm{otherwise}\end{array}$ ${V}_{f}=V\left(1+\frac{p}{E}\right)$ $\mathrm{\beta }=1+\frac{p}{{p}_{\mathrm{atm}}}$ $\mathrm{\gamma }={\mathrm{\beta }}^{\frac{1}{k}}$ $p={p}_{A}$ $q={q}_{A}=\frac{\mathrm{d}{V}_{f}}{\mathrm{d}t}$

Variables

 Name Units Description Modelica ID $p$ $\mathrm{Pa}$ Pressure across component p $q$ $\frac{{m}^{3}}{s}$ Flow rate through component q

Connections

 Name Description Modelica ID $\mathrm{portA}$ Hydraulic port portA

Parameters

 Name Default Units Description Modelica ID $\mathrm{\alpha }$ $0.005$ $1$ Relative gas content, $\frac{{V}_{g}}{V}$ alpha $k$ $1.4$ $1$ Heat ratio of gas k $V$ $1$ ${m}^{3}$ Volume of chamber V