GPS-X Technical Reference

107 Suspended Growth Models
The regression parameter A 6 can be accessed in GPS-X in the
Input Parameters > Operational > More form. The parameter A 6 was estimated by
Hydromantis uses linear regression to fit Equation 6.26 to the solid curve in Figure 8 of
Pöpel and Wagner (1994). In order to perform the regression it was necessary to first
adjust the airflow per diffuser and the diffuser density to match the SOTE of 20 % at
depth of 5 m shown in Figure 8 of Pöpel and Wagner (1994).
The deep tank SOTE correlation is only applied for fine bubble diffusers. It can be
turned off by setting the parameter A 6 to zero in GPS-X.
Blower Wire Power
The wire power in kW consumed by the blowers in order to deliver the required air is
calculated in GPS-X as follows:
Equation 6.28
where:
DP
e
= delivered power of blowers (kW)
= overall efficiency of mechanical equipment (i.e. blowers, motors,
coupling, and gearbox)
The overall efficiency of the mechanical equipment is entered into GPS-X in the
Input Parameters > Operating Cost form of most biological objects. The delivered
power of the blowers is calculated using the adiabatic compression equation (Mueller et
al., (2002)):
Equation 6.29
GPS-X Technical Reference