instead of petroleum-based fluids as working media, such as pure water or
biodegradable fluids. Eliminating leakage is one of the most important challenges that hydraulic technology faces at present. When the hydraulic system is
no longer troubled by leakage, the competitiveness of hydraulic technology will
increase significantly.
(6) Application of computer-aided engineering
The rise of Computer-Aided Engineering (CAE) in the 1980s has brought
hydraulic technology to a new stage. By means of computer simulation, the
designer of hydraulic system circuit and component can quickly and economically inspect his ideas and schemes, which save a lot of time and obtains
the best intuitive results. Computer-aided design (CAD) was used as a simple
method to draw hydraulic circuit diagram and hydraulic component diagram in
the early years. Today, their function is much more than that. Now it is moving
toward performance prediction. The entity modeling method can not only draw
the entity diagram, but also evaluate the performance data such as strength,
weight, center of gravity, and moment of inertia. The designer of hydraulic
components will be able to predict the hydrodynamic properties of components
by deliberating the hydrodynamic relationship and carrying out virtual experiments, i.e., simulation tests. This evaluation technology prior to the prototype
has been widely used. The computer-aided design of hydraulic system needs an
effective CAD program group. Each component in the system has its own
independent mathematical model. The program contains a large capacity
component model library. Building component models requires a lot of
parameter data. These data are usually not available to manufacturers.
Therefore, although there are many hydraulic system CAD programs in the
world, they have not been widely used. Software vendors’ models are usually
not perfect enough, but self-made models require specialized skills. Moreover,
it is not easy to transition from mathematical expressions to real hardware
features and eliminate the differences between models and real hardware. These
models must include not only the steady-state results, but also the differential
equations that form the basis of the dynamic response. Dynamic performance
evaluation is a necessary work to simulate a system. Failure to perform
dynamic performance evaluation will result in imperfect simulation results.
Before the design of hydraulic circuit, a high level of engineering analysis is
needed, that is, required by the original equipment manufacturer and the users
of hydraulic equipment. Without meaningful data specially used to establish
mathematical models, it is difficult to establish mathematical models. Servo
valves are examples with suitable mathematical models. The establishment of
mathematical model of hydraulic components depends on laboratory tests,
otherwise it is difficult to achieve. Mathematical models of pumps and
hydraulic motors require manufacturers to provide leakage and friction coefficients. Other key modeling data, such as the continuous equation required for
the measurement curve, the leakage coefficient varying with temperature and
pressure, and even the transfer function or nonlinear differential equation,
56
9 High-Temperature and High-Speed Gas Turbine Pump …
biodegradable fluids. Eliminating leakage is one of the most important challenges that hydraulic technology faces at present. When the hydraulic system is
no longer troubled by leakage, the competitiveness of hydraulic technology will
increase significantly.
(6) Application of computer-aided engineering
The rise of Computer-Aided Engineering (CAE) in the 1980s has brought
hydraulic technology to a new stage. By means of computer simulation, the
designer of hydraulic system circuit and component can quickly and economically inspect his ideas and schemes, which save a lot of time and obtains
the best intuitive results. Computer-aided design (CAD) was used as a simple
method to draw hydraulic circuit diagram and hydraulic component diagram in
the early years. Today, their function is much more than that. Now it is moving
toward performance prediction. The entity modeling method can not only draw
the entity diagram, but also evaluate the performance data such as strength,
weight, center of gravity, and moment of inertia. The designer of hydraulic
components will be able to predict the hydrodynamic properties of components
by deliberating the hydrodynamic relationship and carrying out virtual experiments, i.e., simulation tests. This evaluation technology prior to the prototype
has been widely used. The computer-aided design of hydraulic system needs an
effective CAD program group. Each component in the system has its own
independent mathematical model. The program contains a large capacity
component model library. Building component models requires a lot of
parameter data. These data are usually not available to manufacturers.
Therefore, although there are many hydraulic system CAD programs in the
world, they have not been widely used. Software vendors’ models are usually
not perfect enough, but self-made models require specialized skills. Moreover,
it is not easy to transition from mathematical expressions to real hardware
features and eliminate the differences between models and real hardware. These
models must include not only the steady-state results, but also the differential
equations that form the basis of the dynamic response. Dynamic performance
evaluation is a necessary work to simulate a system. Failure to perform
dynamic performance evaluation will result in imperfect simulation results.
Before the design of hydraulic circuit, a high level of engineering analysis is
needed, that is, required by the original equipment manufacturer and the users
of hydraulic equipment. Without meaningful data specially used to establish
mathematical models, it is difficult to establish mathematical models. Servo
valves are examples with suitable mathematical models. The establishment of
mathematical model of hydraulic components depends on laboratory tests,
otherwise it is difficult to achieve. Mathematical models of pumps and
hydraulic motors require manufacturers to provide leakage and friction coefficients. Other key modeling data, such as the continuous equation required for
the measurement curve, the leakage coefficient varying with temperature and
pressure, and even the transfer function or nonlinear differential equation,
56
9 High-Temperature and High-Speed Gas Turbine Pump …