What is the difference between Dimensionless and Unitized in the Benefit Type dropdown in the Design Type tab of a Darwin Designer Study? What is the purpose of the Pressure Benefit Coefficient and Exponent?
The “Benefit Type” allows you to choose how Designer considers pressure “benefit” (increase in pressure above the desired minimum) as it goes through trials of finding an optimal design and also the format of how it displays the overall benefit in the summary of a particular Solution. This applies to the “Maximize Benefit” and “Multi-Objective Trade-off” Objective types, where the “consider pressure benefit?” option is used in design events. After calculating a manual or optimized design and clicking the "Solutions" folder, you will see a "Total Benefit" column. This will show as either an overall percent increase (dimensionless) or overall average pressure increase (unitized).
With the Benefit Type set to Dimensionless, Designer will consider the pressure benefit of a particular node based on a percent increase (unitless) of pressure above the desired minimum and will also display the overall benefit as an overall percent increase.
On the other hand, with the Benefit Type set to Unitized, Designer will consider the pressure benefit of a particular node based on the actual increase in pressure above the desired minimum using actual pressure units (such as psi or Kpa). The overall benefit will be displayed as the overall average pressure increase for the saved solution.
Using Darwin Designer to design pipes in WaterGEMS