• XTS—eXtended Time Simulation to model dynamic system behavior
• GSC—Goal Seek and Control to automate the determination of input parameters that will yield desired output values and simulate control functions within systems
• CST—CoST calculations of pipes and components

Each of the AFT Fathom modules can work individually or together within AFT Fathom. And since they are add-on modules to AFT Fathom, they can work with all of your existing system models.

Extended Time Simulation - XTS Module

While steady-state analysis answers many design and operating simulation questions, some questions simply cannot be answered without knowing how critical parameters vary over time. The AFT Fathom XTS module extends your piping system modeling capabilities into the fourth dimension of time by performing a series of steady-state solutions with variables changing automatically through time to achieve a dynamic simulation of your system. For example, the XTS module allows the user to define the geometry of a tank which is used to determine liquid level changes with time.

More than simply calculating time varying values, the XTS module lets you define a wide range of actions to occur during the time simulation, including:

• Pump start/stop and speed variation
• Valve position changes
• Control valve setpoint variation

Extensive text and graphical output clearly displays time varying parameters such as liquid height in tanks, flow and pressure in pipes, pump operating conditions, valve position and more. Graph Results now includes a unique animation feature that dynamically displays time varying parameters along selected flow paths.

Whether you're designing a new system, modifying an existing system or evaluating operating scenarios, when time varying performance is important to your project, you'll find the XTS module uniquely suited to your requirements.

Goal Seek & Control - GSC Module

One of the powerful benefits of system modeling is the what-if potential, the ability to quickly evaluate the effects of changing system parameters. The AFT Fathom GSC module automates this process so that ti requires much less time than traditional, manual iterative analyses. To determine what valve open percent will achieve a target flow is as easy as identifying the valve loss factor as a variable and specifying the value of the desired flowrate.

That's only the beginning, as the GSC module's sophisticated goal seeking engine allows you to define multiple variables and goals at multiple locations throughout the system. Goals can be single point, differentials or sums. The GSC module answers questions such as: what pump speed will achieve a specified total flow to multiple, remote tanks or what positioning of multiple valves will yield a desired differential supply pressure between pieces of equipment in your system.

The possibilities are almost endless and raise the productivity of your system modeling to new levels.

Modeling parameters that may be used as variables or goals include -

• Pumps - speed, flow, head rise, impeller diameter
• Valves - open percent, Cv/K, deltaP, flow
• Reservoirs - liquid level, temperature
• Control valves - setpoint, open percent
• Orifice - diameter, area
• Heat exchangers - heat rate, temperatures, area, U value
• Spray discharge - area, K value, exit pressure

Most of the cost of a typical piping or ducting system is fixed in the initial stages of design where system sizing is determined. Traditional methods impose too much distance between this design stage and cost determination, obscuring the impact of design decisions on system costs. By calculating system costs, the CST module lets you tightly integrate your design and cost estimating process, eliminating the barriers to development of cost effective designs. In conjunction with AFT Fathom's energy cost calculation capabilities, the impact of design decisions on both fixed and life cycle costs are clearly shown. The CST module provides a flexible means of defining system component and piping costs in databases that may be accessed by your AFT Fathom model. In addition to the traditional hydraulic information, output now also contains the total cost and a cost breakdown by component. The CST cost module databases provide the freedom to arrange your cost data as you want, whether it be by component type, equipment category, project or almost any arrangement that fits your needs. Database Manager lets you easily move data between databases, create new databases and manage the data used in your system model. In addition to your own data, the CST module integrates with Aspen Icarus KbaseTM and an optional MeansDataTM module, allowing ready access to the extensive cost information available in these industry standards.

If you're serious about developing cost effective designs, you need the tight integration between your design and its cost provided by AFT Fathom CST.