VM123

VM123
Laminar Flow in a Piping System

Overview

Reference: Crane Company Engineering Division, "Flow of Fluids through Valves, Fittings, and Pipe", Technical Paper No. 410, Chicago, IL, 1969, pg. 4-5, ex. 4-9.
Analysis Type(s): Thermal (pressure) Analysis (ANTYPE = 0)
Element Type(s): Coupled Thermal-Fluid Pipe Elements (FLUID116)
Input Listing: vm123.dat

Test Case

S.A.E. 70 lube oil at 0°F is flowing through a horizontal 5" schedule 40 piping system (of diameter d) at a flow rate w. Determine the pressure drop, Δp, and the Reynold's number Re. Assume that the friction factor is determined by the laminar flow relationship for smooth pipes. The equivalent length of elbow and valves to account for flow losses is a.

Figure 176: Laminar Flow Problem Sketch

Laminar Flow Problem Sketch

Material PropertiesGeometric PropertiesLoading
μ = viscosity = 0.010032 lb-sec/ft2
ρ = 1.7546 lb-sec2/ft4
d = 0.4206 ft
1 = 175 ft
2 = 75 ft
3 = 50 ft
a = 53 ft
w = 2.345 slugs/se/sec

Analysis Assumptions and Modeling Notes

The piping system is modeled using a single element of length = 1 +   2 +   3 = 300 ft. The flow, w, is input at the inlet node. The exit pressure is defined to be zero for reference. An iterative solution is required. A friction factor of 0.05 (input for MU) is assumed for a starting value.

Results Comparison

TargetMechanical APDLRatio
Pressure Drop, lb/ft2 6160.6164.[1]1.001
Re708.708.1.000

  1. Pressure drop Δp is given by the PRES degree of freedom at node 1.