Verification Case 1
PRODUCT: AFT Fathom
TITLE: FthVerify1.fth
REFERENCE: Perry's Chemical Engineers' Handbook, 7th Ed., 1997, McGraw-Hill, Robert H. Perry, Don W. Green, Eds., James N. Tilton, Ph.D., P.E., Author, Page 6-17, 18, Example 6
FLUID: Water
ASSUMPTIONS: N/A
RESULTS:
| Parameter | Tilton | AFT Fathom |
| EGLinlet - Energy Gradeline at inlet (meters) | 0.738 | 0.7397 |
DISCUSSION:
The flow conditions are specified in terms of velocity, at 2.0 m/s. Converting this to flow rate (for diameter of .0525 m) obtains 0.00433 cubic meters per second. The problem is stated in terms of flow requirement with an unknown inlet tank height. This is most easily modeled using an Assigned Flow junction at the inlet. The EGL (energy gradeline) at the inlet will yield the tank height.
The inlet loss factor of 0.5 is modeled as part of the inlet Assigned Flow.
The friction factor in the reference is the Fanning friction factor, whereas AFT Fathom uses the Moody friction factor. The two differ by a factor of 4. If this ratio is applied, results using either friction factor are the same.
The problem does not state the discharge boundary condition very clearly, but reading through the solution procedure it is evident that discharge condition is static pressure at atmospheric pressure. This is modeled using an Assigned Pressure junction at 1 atm.
The loss factor at the elbow, as developed in the reference, is 0.37.
The problem solution as given in the reference is 0.73 feet. However, if the numbers as given in the reference are multiplied, a value of 0.738 m results. The author apparently rounded the value down to 0.73.
