systemElementsType

Library of the equipment that systems are built from, e.g. batteries, pumps, pipes and valves. Each element is defined once, with its geometry and its mass (vehicleElementBaseType), and is installed in a vehicle as often as needed by components that reference its @uID (componentType).

Classification

An element is sorted into a domain by the physical quantity it delivers or transports, and within the domain by its role. The input that drives the element does not decide the domain. An electric motor, for example, delivers mechanical power and is therefore a mechanical conversion element, whereas a generator, driven by a shaft, delivers electrical power and is an electrical conversion element. The domains are <electricalElements>, <mechanicalElements>, <pneumaticElements>, <hydraulicElements> and <thermoFluidElements>. Some kinds of element, e.g. pipes or valves, occur in several domains.

Roles

Within a domain, the role describes what an element does with the quantity:

• <storageElements> retain energy or a working medium and make it available for later use, e.g. batteries, reservoirs or springs.

• <conversionElements> transform energy or change the state of a medium, e.g. its pressure, temperature, flow or phase; examples are generators, pumps and heat exchangers.

• <distributionElements> transport, route, split, join or connect a quantity, e.g. cables, pipes or drive shafts.

• <controlElements> switch, regulate, isolate, protect or sense a quantity, e.g. circuit breakers, valves or clutches.

• <consumerElements> use electrical power to provide a service, e.g. light or a display, without delivering power to another domain. Only the electrical domain has consumer elements.

Distribution elements

Distribution elements such as pipes, cables and drive shafts describe the basic geometry of one section, e.g. a straight tube of a given diameter and length, together with its mass. Their actual route through the vehicle is not described. This follows the usual practice in design, where the routing is not yet fixed: a line is represented by one or more such sections, each installed as a component.

Generic elements

Every level of the library offers a generic container as a fallback for an element that fits no more specific class:

• <genericElements> for an element whose domain is not yet known or that fits none of the domains,

• a generic container in each domain, e.g. <genericElectricalElements>, for an element whose role is not yet known,

• a generic container in each role, e.g. <genericStorageElements>, for an element of known domain and role that fits none of the specific containers of that role.

An element is placed as specifically as its definition allows, so that the generic containers remain the exception.

Two elements of a fuel cell propulsion unit, sorted by the quantity they deliver: the battery delivers electrical power and is an electrical storage element, the motor delivers mechanical power and is a mechanical conversion element. The transformation of its cuboid moves the battery so that the origin of the element lies in the center of the box.

<systemElements>
    <electricalElements>
        <storageElements>
            <batteries>
                <battery uID="battery">
                    <name>Battery, 30 kWh</name>
                    <geometry>
                        <cuboids>
                            <cuboid>
                                <lengthX>0.8</lengthX>
                                <depthY>0.45</depthY>
                                <heightZ>0.3</heightZ>
                                <transformation>
                                    <translation>
                                        <x>-0.4</x>
                                        <y>-0.225</y>
                                        <z>-0.15</z>
                                    </translation>
                                </transformation>
                            </cuboid>
                        </cuboids>
                    </geometry>
                    <mass>
                        <mass>150</mass>
                    </mass>
                </battery>
            </batteries>
        </storageElements>
    </electricalElements>
    <mechanicalElements>
        <conversionElements>
            <electricMotors>
                <electricMotor uID="electricMotor">
                    <name>Propulsion motor, 410 kW</name>
                    <geometry>
                        <cylinders>
                            <cylinder>
                                <radius>0.22</radius>
                                <height>0.35</height>
                            </cylinder>
                        </cylinders>
                    </geometry>
                    <mass>
                        <mass>80</mass>
                    </mass>
                </electricMotor>
            </electricMotors>
        </conversionElements>
    </mechanicalElements>
</systemElements>