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The Control
Simulator stores all information in databases. One
useful way to think of and use a database is that it
contains in one file all of the simulation cases related to
a single project. Each simulation case (charging the
supply system or closing a valve, for instance) is contained
in an assembly, with one (or more) assembly per case.
The
structure of a database allows the Control Simulator to
store as many components and assemblies as the user decides
and is only limited by the size of the drive containing the
database file. Because of this flexibility, the user may
choose to use one database to store one assembly, an entire
project, or all projects. When requested by the user, the
Control Simulator creates a new database by creating a copy
of the prototype file Template.mdb. For this reason, any
component definitions and assemblies included in the
Template.mdb file will also be present in the newly created
database.
Control
Simulator database files are named Filename.mdb
A component
in the Control Simulator represents a physical hydraulic
component or group of components that can be analyzed as a
unit. A collection of properties called intrinsic properties
defines a component in the Control Simulator. These
properties do not change regardless of where the logical
component (the representation of the physical component or
components) is used. If you change the value of one of
these intrinsic properties (such as the volume of an
accumulator), that change is applied to every instance of
the component any assembly where it is used.
In order to
use components having different intrinsic properties you
must define different components. For example, to use
a 20 gallon accumulator in one assembly and a 5 gallon
accumulator in another, you must define two accumulator
components.
An instance
is defined as a reference to a component definition from
within an assembly. It consists of both the component's
intrinsic properties as well as of any applicable project
properties.
In the Control Simulator, an assembly
is defined as a collection of components that are
interconnected via logical links (see Logical link) and
represent a hydraulic circuit (or a portion of one).
Intrinsic
properties are part of the basic definition of a component.
These are properties that do not change regardless of where
the component is used. Example: the internal empty volume of
an accumulator, the stroke of a valve, or the outside
diameter of a stainless tube. (see Project Property)
A logical
link is the means by which component sequence and connection
configuration is established in the Control Simulator GUI.
These are depicted as lines running from an outlet port of a
component to an inlet port of the next downstream component.
The upstream side of the logical link is always shown in a
different color (red when unselected, blue when selected).
Project
properties are associated with an instance of a component.
These properties may change depending on where a component
is used. Example: the precharge pressure in an
accumulator, the starting position of a valve, or the length
of a control line. (see Intrinsic Property)
Although
associated with an individual instance of a component,
project properties are actually part of the assembly and are
saved as part of the assembly. For instance, suppose
you have an assembly using ˝” tubing and you want to see the
effect of changing to 3/8” tubing. By dragging the
3/8” tubing from the database and dropping it on top of the
˝”, all of the intrinsic properties (such as diameter and
wall thickness) are replaced by those of the 3/8” tubing.
But project properties (like the length of the tubing) are
not changed.
Assemblies
can be used as building blocks for defining more complex
assemblies. The top-level assembly is the assembly that is
active when the simulation is being run. Any sub-assemblies
used as building blocks for the assembly being analyzed are
said to be contained by the top-level assembly.
A source
component is a component that can be placed at the control
location (the platform, for instance). Source is a
functional title, not an indication of the direction of
fluid flow. The source may be a supply or vent for
fluid depending on the pressures in the line and the source.
The Control Simulator currently supports two types of
sources: A pump component and a pressure source component.
Also, the
end of a line, component, or assembly that is nearest to the
control location is called the source end. As with the
source component, “source” does not imply direction of fluid
flow. Fluid can flow into or out of the source end.
Flow is always positive when the fluid is moving from a
source toward a discharge. (see Discharge)
A line is the means for conveying
hydraulic fluid from one component to another. The two types
of lines currently supported by the Control Simulator are
the hard tubing and the thermoplastic hose.
The hard tubing model applies to any
conduit that exhibits elastic, linear stretching of the
walls with changes in pressure. Stainless steel,
titanium, and carbon steel, are obvious examples of hard
tubing.
The thermoplastic model applies to any
conduit that exhibits non-linear, viscoelastic, time
dependent stretching of the walls with changes in pressure.
Hoses reinforced with Kevlar or polyester, and PVC pipe
are examples of conduits that require the thermoplastic hose
model.
A discharge
component is a component that can be placed at the “far” end
of a line, away from the control location (the tree, for
instance). Discharge is a functional title, not an
indication of the direction of fluid flow. The
discharge may be a supply or vent for fluid depending on the
pressures in the line and the discharge.
Also, the end of a line, component, or
assembly that is farthest from the control location is
called the discharge end. As with the discharge
component, “discharge” does not imply direction of fluid
flow. Fluid can flow into or out of the discharge end.
Flow is always positive when the fluid is moving from a
source toward a discharge. (see Source)
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