AFT Arrow


Compressible Pipe Flow Analysis & System Modelling Software

Software from Applied Flow Technology will simulate steady-state Newtonian liquid (incompressible) flow, gas (compressible) flow and unsteady liquid flow (water hammer) in complex pipe system. Non-Newtonian/nonsettling liquids and settling particulate slurries can also be modelled.

AFT programs share an identical user-interface where schematics of the pipe systems can be developed in flowsheet format using a convenient drag-and-drop technique.

AFT’s presentation of pipe flow results – flows, pressures, changes in density etc in graphical format - is particularly comprehensive providing the user with informative feedback on the performance of the system.

AFT Arrow is a fluid dynamic simulation tool used to calculate pressure drop and flow distribution in gas piping and ducting systems.



Evaluate AFT Arrow

Download a fully-functional licence with specific limitations...

  • Build and run any model with a maximum of five pipes.
  • Build and run models of any size using air, fixed compressibility factor, and pre-set resistances
  • Load and run any of the files from the Examples or Verification directories

Designed for fluid systems containing

  • Steam
  • Compressed air
  • Chemical and petrochemical process gases
  • Natural gas transport
  • And many more

AFT Arrow is particularly useful for

  • Pipe and Duct Sizing
  • Relief valve sizing and system calculations
  • Compressor and Fan sizing and Selection
  • Control Valve sizing and Selection
  • Simulating System operation and component interaction
  • Choked Flow calculations
  • Evaluating pipe insulation and heat transfer in pipes and heat exchangers
  • Troubleshooting existing systems to determine the cause of operational problems

AFT Arrow

  • Accurately simulates individual system components and their interaction including effects of heat transfer, real gases and choked flow
  • Tightly integrates equipment characteristics, analysis and output with your system’s schematic representation
  • Provides a wide array of features without sacrificing your need for a short learning curve
  • Frees you to focus on your system, not the mechanics of software manipulation
  • Significantly improves the quality of systems engineering you can achieve, leading to less costly, more efficient and more reliable piping systems

AFT Arrow Features

  • Advanced marching methods provide highly accurate results
  • Detailed modelling for fans and compressors, control valves, heat exchangers and other components
  • Conduct compressor and fan energy cost analysis
  • Conduct thermal analysis including piping heat transfer and heat exchanger modelling
  • Scenario Manager tracks all design variants and operational possibilities in a single model file with data linkage
  • Integrated graphing and reporting
  • Built-in library of gases and fittings can be extended and customized
  • Built-in ASME steam properties
  • Optional Chempak™ add-on utility provides a thermophysical database of almost 600 gases - allows you todefine non-reacting pre-mixtures, and simulate dynamic flow mixing



Optional Module
Automate the identification of input parameters that will yield desired output values and simulate control functions within systems

Case Studies
View Case Studies using AFT software


AFT Arrow provides comprehensive, compressible pipe flow analysis and system modeling capabilities combined with ease-of-use. Addressing open and closed loop systems, AFT Arrow includes a built-in library of fluids and fittings, variable model configurations, fan/compressor and control valve modeling and much more. With the optional Chempak add-in, a thermo-physical database of approximately 600 gases is available to further expand the envelope of your analysis and design. AFT Arrow goes beyond the boundaries of fluid flow analysis, with thermal analysis capabilities including piping heat transfer, heat exchanger modeling and varying fluid properties. 

AFT Arrow employs a robust solver using proven matrix methods to solve the governing equations of pipe flow to conduct a true and rigorous compressible flow solution. AFT Arrow is unique in its ability to solve for adiabatic, isothermal and generalized heat transfer conditions and with sonic choking.

More than flow analysis, AFT Arrow let's you build your piping system in software. Vary pipe sizes, compressor/fan curves, valve settings, fluid properties, operating lineup...virtually anything you can do with the real system can be done within AFT Arrow, accurately simulating the individual system components and their interaction. Whether you're designing new systems, modifying existing ones or analyzing system operations, The ability to analyze alternatives and the insight provided by an AFT Arrow model significantly improves the quality of systems engineering you can achieve, leading to less costly, more efficient and more reliable piping systems.

Like Fathom, Arrow has optional modules which extend its capabilites, viz Goal Seek and Control (GSC) and Costing (CST).

AFT Arrow Goal Seek & Control (GSC) Module

Identify Input Parameters That Yield Desired Output Values and Simulate Control Functions
One of the powerful benefits of system modelling is the ability to quickly evaluate the effects of changing system parameters.
The AFT Arrow GSC module lets you:

  • Save time by avoiding manual iterative analyses
  • Define multiple variables and goals at multiple locations throughout the system
  • Answer questions such as:
    • What positioning of multiple valves will yield a desired differential supply pressure between pieces of equipment in your system?
    • What compressor/fan speed will achieve a specified total flow to multiple, remote tanks
  •  Increase your productivity

Modelling parameters that may be used as variables or goals include:

  • Compressors and Fans - speed, flow, head rise
  • Valves - open percent, Cv/K, deltaP, flow
  • Tanks - pressure, temperature
  • Control valves - setpoint, open percent
  • Orifice - diameter, area


Accutech provides both engineering and key-stroke support for Arrow backed up the developer, Applied Flow Technology. The annually renewable Support, Update and Maintenance (SUM) agreement ensures that your licence is always up-to-date and that we can provide timely assistance. Send us your design file and we can explain your results, check for errors and feedback suggestions for improving your design. We use our video-chat capability to navigate you through your model, whilst we both concurrently view the flowsheet.

We can provide training on Fathom via our two- or three-day training course.