Spring Loaded Accumulator
Hydraulic accumulator with spring-loaded back pressure
Description
Equations
Variables
Connections
Parameters
The Spring Loaded Accumulator component consists of a preloaded spring, a piston, and a hydraulic chamber connected to a hydraulic port. When the fluid pressure at the port exceeds the preloaded spring pressure, fluid flows into the chamber, moving the piston and compressing the spring. The amount of fluid stored in the accumulator depends on the size and spring load. The stroke of the piston is restricted by end cushion parameters used to set the boundary of the component respectively.
arel=dvreldt vrel=dsreldt
fspring=−A⁢ppreload−c⁢srel−d⋅vrel
fc1={0srel<LmaxcES⁢srel−Lmaxotherwise fc2={00≤srelcES⁢srelotherwise
fd1={0srel<LmaxdES⁢dsreldtotherwise fd2={00≤sreldES⁢dsreldtotherwise
fe1={0fc1+fd1≤0fc1+min⁡fc1,fd1otherwise fe2={00≤fc2+fd2fc2+max⁡fc2,fd2otherwise
p=pA
q=qA=A⁢vrel
vrel=dsreldt
fchamber=p⁢A
m⁢arel=fchamber+fspring−fe1−fe2
Name
Units
Modelica ID
p
Pa
q
m3s
srel
m
Relative distance of the piston from the initial position
s_rel
vrel
ms
Relative velocity of the piston
v_rel
arel
ms2
Relative acceleration of the piston
a_rel
portA
Hydraulic port
Geometry
Default
A
0.01
m2
Wetted area of piston
0.1
kg
Mass of the piston
Lmax
0.4
Maximum stroke length of the accumulator
Hard Stop
cES
1·1010
Nm
Hard stop stiffness
c_ES
dES
1·106
N⁢sm
Hard stop damping
d_ES
Spring
c
1·104
Spring constant
d
0
Piston viscous friction coefficient
Preload Conditions
ppreload
1·105
Spring preload pressure
p_preload
See Also
Accumulators
Hydraulics Library
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