Extended Time Simulation (XTS) Add-on Module lets engineers define a wide range of actions to occur during the time simulation.
Tank Level Tracking
Predict how long to fill and drain tanks
Pumps & Compressors
Start/stop and speed variation
Valves
Valve position changes
Control Valve
Setpoint variation
Time-Based Simulation
XTS allows engineers who are designing or troubleshooting industrial gas and steam systems to easily model liquid and gas transients.
Transient Events
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- Tank filling, charging, and blowdowns
- Pump/compressor/fan speed changes
- Valve position Changes
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Reporting Features
- Text and graphical output clearly display time-varying parameters such as:
- liquid height or gas pressure in tanks
- flow and pressure in pipes
- pump/compressor operating conditions
- valve position and more
- Unique animation feature that dynamically displays time-varying parameters along selected flow paths
Contact AFT for a Free 2-week trial of the XTS Module.
Model Transients
What kinds of transients can the XTS Module model?
The Extended Time Simulation (XTS) add-on module can help engineers efficiently model a wide range, including:
- Incompressible liquid levels, valve open/close, pump speed changes, relief valve opening, and more.
- Compressible tank pressure, valve open/close, compressor speed changes, relief valve opening, and more.
Just as important, the XTS module can model time transients, event transients, and inherent transients. Time transients are changes that are specified to occur based on the model time. Event transients, on the other hand, are triggered by an event that occurs in the system.
Many kinds of events can be used, such as pressure, flow, velocity, and liquid level. Inherent transients are changes that occur by the very nature of a system component.
Two examples would be the liquid level change that occurs in a finite reservoir (or tank), while another would be a check valve opening and closing as a result of flow reversals.
Heat Transfer
AFT Fathom and Arrow model heat transfer, so does this mean XTS does as well?
No, when using the module, heat transfer is turned off because the module does not model transient heat transfer. This is primarily because the input required by the user to model transient heat transfer would be very complicated for some components.
XTS works by adjusting boundary conditions and running steady-state simulations. Therefore, changes in pressure and temperature instantly propagate through the entire system. Due to the complexities of this instantaneous effect combined with the fact that changes in pipe wall temperature are generally very slow, AFT feels it is better to restrict the capabilities rather than force the user to make additional far-reaching assumptions.
Many junctions in XTS do allow the user to impose thermal conditions on the model. For example, a known pressure can vary its temperature over time, a heat exchanger can represent exchange with an external fluid with changing conditions, and a finite tank can have a user-defined heat rate applied to it. Arrow XTS does not model the effect of stored heat in these components.
Consider a tank, for example. What part of the tank structure participates in transient heat transfer? The immediate tank boundaries would seem to be fairly clear, but what about the supporting structure? It too would be involved to some degree, but to model this would require extensive definition by the user.
Module License
Do I have to have one XTS module license for each AFT Fathom or Arrow license?
This is true only for standalone licenses. For network licenses, there does not need to be a one-to-one relationship. This provides users the flexibility to choose the level of capability they need.
There are unique versions of XTS for AFT Fathom and AFT Arrow. The XTS modules are not interchangeable between the software.
For example, you may have several AFT Fathom or Arrow licenses deployed on your network but only need to use the XTS Module half the time and, therefore, have a correspondingly lower number of module licenses. If you open a model previously saved using the XTS Module, AFT Fathom will first try to activate the module.
If all of the module licenses are being used, a message will be displayed telling you a module license is not available and provide you a choice of continuing to open the model or canceling the load.
This same message will remind you that if you do open and work with the model, XTS Module specifications contained in the model may be lost.
Webinar:
Which ‘Transient’ Analysis Do I Use?
What do you mean by “transient analysis”? AFT has two engineering solutions to help you decide which transient analysis is the best for your project. AFT Fathom XTS Module and AFT Impulse. But when exactly should you use the AFT Fathom XTS Module vs. when would you use AFT Impulse? Do you need both? This webinar will showcase an example of a system where you would need BOTH the AFT Fathom XTS Module and AFT Impulse.
AFT Software Add-On Modules
Settling Slurry (SSL)
Models the effects of pumping fluids containing settling solids using the Wilson/GIW method.
Add-on Module for:
Goal Seek & Control (GSC)
Significantly reduce your iterations. Identify input parameters that yield desired output values and simulate control functions.
Add-on Module for:
Extended Time SImulation (XTS)
Models dynamic system behavior and how critical system parameters vary over time.
Add-on Module for:
Automated Network Sizing (ANS)
Evaluates the complex interaction of system variables to reveal combinations of cost savings.
Add-on Module for:
Pulsation Frequency Analysis (PFA)
Helps identify pipe acoustical frequencies to avoid resonance from excitations.
Add-on Module for:
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