Verification Case 23
PRODUCT: AFT Fathom
TITLE: FthVerify23.fth
REFERENCE: Hydraulic Institute, Effects of Liquid Viscosity on Rotodynamic (Centrifugal and Vertical) Pump Performance, ANSI/HI 9.6.7-2010, 2010, Hydraulic Institute, Page 13
FLUID: Viscous fluid through a pump
ASSUMPTIONS: N/A
RESULTS:
| Parameter | HI Standard | AFT Fathom |
| CQ | 0.938 | 0.9381 |
| CH | 0.938 | 0.9381 |
| CE | 0.739 | 0.7390 |
| CH at 60% Flow | 0.958 | 0.9578 |
DISCUSSION:
The kinematic viscosity in centistokes (120 cSt) was converted to dynamic viscosity for use in AFT Fathom assuming a specific gravity of 0.9. This results in a viscosity of 107.93 cp. Discharge and suction tanks and pipes were used, with the pipe diameters made very large to minimize pressure loss. The reservoir head difference was 300 feet, which corresponds to the problem statement.
The correction factors, CQ, CH and CE, all correspond closely to those in the handbook. The value of CE given in the reference problem was shown as 0.738 in the calculation, but 0.739 in Table 9.6.7.4.5b. In addition, CE is calculated as 0.739 if calculated using the same numbers as given in Step 4, so it is assumed that the difference in the value given in the reference includes round-off errors.
The CQ, CH, and CE values in AFT Fathom are displayed in the Pump Summary.
