AFT Blog

You can print all of or select portions of your model data window in order to have a hard copy of your input. Likewise you can print all of or select portions of your output window in order to have a hardcopy of the output. Printing both of these windows allows you to have hardcopies and backups of everything you would need to perform calculation checks on your model. After building your model and entering all of the required data, browse to the Model Data window and click “View/Model Data Control”. After setting up the input data to be displayed, click...

Filters and screens impose a pressure drop that varies with flow rate. The variation is non-linear, but manufacturers will often provide only one data point for pressure loss at the design flow rate. Using a single point, or constant pressure drop, can produce significant inaccuracies in your model. With this in mind, AFT offers the “Fill As Quadratic” option for entering loss data.   Using only a single point, “Fill As Quadratic” will create two additional points for you. This first is simply 0,0; zero flow produces zero pressure drop. The second point is 2 x Flow and 4 x Pressure...

You can jump from junction to junction or from pipe to pipe by pressing F5 while in a specifications window.

After you receive your AFT software, you will probably wonder how to learn the software quickly so you can begin using it.  AFT provides a very handy Quick Start Guide for each software product in English Units and SI Units.  These quick start guides are short, concise, would take maybe a day of your time, and are extremely powerful to assist you in producing highly accurate and advanced models! With larger companies, sometimes the AFT software will go straight to the IT department for installation and the engineer may never see the hard copy of the quick start guides.  Not to...

Using “Specified Heat Rate In Constants” for the thermal model of heat exchangers can often cause problems in system models.  The reason why is because this thermal model type causes the heat exchanger to act like an “assigned heat input” junction as does an assigned flow junction does for providing constant flow rates.  Another problem is that this thermal model can cause unrealistic temperature changes across a heat exchanger.  When the heat rate is specified and the mass flow rate and heat capacity are calculated based on the system solution, the temperature change will be whatever is required to maintain the...

Applicable to: Arrow GSC Add-on Module, Fathom GSC Add-on Module When searching for a variable value that will yield a specified goal, GSC will investigate all possible variable values. There are some cases, however, where you may want to limit the range of investigation. An example might be using GSC to find the pump or fan/compressor speed to yield a defined goal. On its own GSC will consider any speed value from 0% on up. You may want to limit this to a maximum of 100% speed and/or some lower speed limit based on manufacturer's information or experience. This can be...

To create a version of your model with input values equal to the solved GSC variables, with the Output window open, make a disconnected scenario from the View menu.