MapleSim Hydraulics Library from Modelon
Accu2 — Hydro-pneumatic accumulator (refined gas model)
The Accu2 component describes a hydro-pneumatic accumulator. The model of the charge gas is more refined than in the Accu1 component. There is a valve at the inlet port. Oil flows into the accumulator if the pressure at port_A is higher than the gas pressure, pgas. A lower limit is given for the gas pressure, pgas, by the precharge pressure. This is calculated from the volume of the accumulator, the temperature of the environment and the gas mass. The gas volume at t = 0 must be less than or equal to the volume of the accumulator. There is a check whether this condition is met. The model uses the Beattie-Bridgeman-equation to calculate the behavior of nitrogen as the charge gas. The following m-files calculate parameters for model Accu2. They can help with the numerical analysis of an accumulator and are to be used with MATLAB(R), not Dymola(R). This model will be replaced by a new model next release.
Calculates the pressure for given temperature and specific volume.
Calculates the specific volume for given temperature and pressure.
Calculates the specific capacity for constant volume.
Hydro-pneumatic accumulator with a simple model of the charge gas.
Pressure at port A
Port A, where oil flows into the component (0<q, pB<pA means 0<Δp)
Volume of accumulator
Gas volume at t = 0
Temperature of environment
Temperature of charge gas at t = 0
Gas mass (default is for 1e-3 m3 und 3.5 MPa)
Thermal time constant
Mean value of cv
Geometric volume at port A of TwoWayValve
Geometric volume at port B of TwoWayValve
Overlap of valve relative to max. displacement = 1
Nominal flow rate of valve
Pressure drop at qnom of valve
Diameter of equivalent orifice to model leakage of closed valve
Laminar part of orifice model
Turbulent part, k2=1Cd2
Natural frequency of spool
Damping coefficient of spool
Gas pre-charge pressure, computed
MapleSim Hydraulics Library from Modelon Overview
Download Help Document
What kind of issue would you like to report? (Optional)
Thank you for submitting feedback on this help document. Your feedback will be used
to improve Maple's help in the future.