Isothermal liquid networks do not undergo
temperature or viscosity changes due to any
processes occurring in or around the network, but
can support elevated or reduced
A water supply system consisting of three pumping stations located at 45, 25, and 30 m with respect to to the reference plane, respectively. All three stations are expected to pump water in a tank located at 61 m. All tanks are large enough to assume that the fluid level remains nearly constant, allowing them to be modeled with the Constant Head Tank block. The initial volume of water in each tank is set to 100 m^3. Each pumping station consists of a tank, two centrifugal pumps installed in parallel, and a prime mover rotating at 1700 rpm. The pump characteristics are specified using lookup tables.
A simplified version of a lubrication system fed with the centrifugal pump. The system consists of five major units: Pump Unit, Scavenge Unit, Heat Exchanger Manifold, Nozzle Manifold, and Control Unit. Both the pump and the scavenge unit are built around the centrifugal pump. The Scavenge Unit collects fluid discharged by nozzles and pumps it back into the reservoir of the Pump Unit. The Control Unit generates commands to bypass either the heat exchanger, represented as a local resistance, or the nozzles block. In a real system, these commands are generated by temperature sensors installed in lubrication cavities.
A typical power unit consisting of a fixed-displacement pump driven by a motor through a flexible transmission and a pressure-relief valve. A variable orifice serves as a load for the system.
A typical power unit consisting of a fixed-displacement pump driven by an angular velocity source, a pressure-relief valve, a pressure-reducing valve, and two variable orifices.
A circuit that is equipped with a load-sensing velocity regulator installed between the pump and directional valve. Unlike a conventional meter-in velocity control, the load-sensing device automatically adjusts output pressure of the pump in such a way that it equals the sum of the preset pressure drop across the pressure-compensated flow control valve and the pressure induced by load. The pilot-operated pressure-relief valve in the Load-Sensing Velocity Control block is built of the Poppet Valve and the Hydraulic Double-Acting Valve Actuator blocks.
A circuit using a load-sensing and pressure-limiting unit in a conventional reciprocal system with variable load on the forward stroke. The unit limits output pressure to 300 bar and maintains a preset pressure drop in 10 bar across velocity control orifice on the discharge port of the pump. The unit is built of two 3-way, 2-position valves, two single-acting hydraulic valve actuators, and one double-acting hydraulic valve actuator.
A test rig designed to investigate interaction between an axial-piston pump and a typical control unit, simultaneously performing the load-sensing and pressure-limiting functions. To assure required accuracy, the model of the pump must account for such features as interaction between pistons, swash plate, and porting plate, which makes it necessary to build a detailed pump model.
A closed-loop actuator that consists of a proportional 4-way directional valve driving a double-acting hydraulic cylinder. The cylinder drives a load consisting of a mass, viscous and Coulomb friction, constant force, and a spring. The actuator is powered by a variable-displacement, pressure-compensated pump, driven by a constant velocity motor. Pipelines between the valve, cylinder, pump, and the tank are modeled using the Hydraulic Pipeline blocks.
A pressure-compensated 3-way flow control valve. This valve maintains constant flow rate through the main hydraulic motor, which is connected to the pressure-compensated outlet of the flow control valve. It acts as a priority valve, diverting the excess flow to the auxiliary hydraulic motor if the main hydraulic motor receives enough fluid to maintain a preset angular velocity. The auxiliary motor is shut off completely if there is insufficient flow to power the main hydraulic motor.
A well jet pump installation. The well jet pump installation presented in this example consists of a surface-mounted centrifugal pump and a jet pump installed in the well below the surface of the water.
The fuel supply system represented in the example consists of three tanks and an engine. The engine is fed from the central tank, while fuel from the left wing tank and the right wing tank is pumped to the central tank with respective pumping stations. Each pumping station consists of two centrifugal pumps, connected in parallel, with check valves installed in the pump outlets to prevent back flow. The pumps are driven by prime movers at angular velocity of 7200 rpm. The movers are simulated with the ideal angular velocity source.
A classical problem of fluid transportation: to determine flow rates, pressures, and fluid volumes in a system built of three constant head tanks. The tanks are located at different elevations and connected with pipelines combined together in a common node located at 50 meters with respect to the reference plane. The simulation time is set to 50 seconds, which is enough for system variables to settle down and reach near steady-state values.
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