Introduction
The Multi Calc feature in FluidFlow allows you to run multiple calculations by varying a property across a range of values. This powerful tool helps engineers perform sensitivity analyses, optimize designs, and explore "what-if" scenarios efficiently without manual recalculation.
Follow along with our Quick Start video for a visual reference.
Multi Calc automates the process of running your model multiple times with different input parameters, saving you hours of manual work.
Key Benefits
Quickly analyze how changes to a specific parameter affect your entire system
Identify optimal operating conditions and design parameters
Generate comprehensive data for reports and presentations
Evaluate system performance across various scenarios
Using Multi Calc
Access the Multi Calc tool
Go to Tools → Multi Calc in the main menu
Define the following:
Description: (Optional) Enter calculation description
Property to Change: Select the property you wish to vary (e.g., pipe inside diameter, pump operating speed, valve % open, elevation)
Apply To: Define the element where to apply the change in property (you can either select or specify the element/s)
Track Results: Select or specify the element/s where the results will be checked
Input Source: Choose one of the following variation methods:
Step-wise (e.g., from 50 to 100 in steps of 10)
Incremental (specific number of evenly spaced values)
User-entered (manual list of custom values)
Excel link (import values from a spreadsheet column)
Configure value sequence
For step-wise: Enter start value, end value, and number of steps
For incremental: Enter start value, end value, and increments between values
For user-entered: Enter each value separated by commas
For Excel link: Browse to select your file and specify the column containing your values
Run Multi Calc
Click "Run" to start the process
A progress bar shows the status of the calculations
The software automatically solves the model for each input value
Review results
Results appear in a table under the "Report" tab
Use "Save to Excel" or "Preview" to export results in various formats
Configure result parameters through Options → Environment → Excel Columns. In the Set Visible Excel Properties window, select which input and result parameters to display for each component.
Optional: Create graphs from the results to visualize trends
Example Applications
Scenario | Multi Calc Application | Benefit |
Pipe sizing optimization | Vary pipe diameters to find cost-effective sizes | Balance material costs with pumping energy requirements |
Pump analysis | Test different pump speeds or impeller diameters | Identify the most efficient pump settings for your system |
Control valve analysis | Vary valve opening percentages | Determine optimal control valve positions for your system |
System expansion planning | Model increasing flow demands | Verify whether the existing system can handle future expansions |
Pro Tips
Model dynamic systems
Use Multi Calc to simulate simple dynamic behavior like tank filling/emptying
Combine with Excel for time-based calculations (e.g., calculate filling time from flow rates)
Optimize your workflow
Use keyboard shortcuts (Alt+T+M) to quickly access Multi Calc
Set up templates for common analysis scenarios
Advanced data visualization
Export results to Excel and create custom charts to visualize trends
Next Steps
FluidFlow supports simple dynamic analysis via scripting, allowing you to simulate parameter changes over time. For more advanced time-dependent simulations, consider exploring FlowDesigner (coming soon), which offers full transient analysis capabilities.