To model and embed a junction and separation (tee or y fittings) in a branch portion of a network of fluid, Mecaflux standard provides a simplified method to cover all the cases encountered.

head loss calculation in junction and separation (tee or y fittings) in fluids networks , can be useful if you want to compare the pressure drop of two branch portions of a network. (Reminder: The flow in each branch / segment of an separation of stream, meet the condition of equal pressure drop in each downstream branch, together with the condition : total of the downstream flows = flow upstream. If two conditions are met we solved the flow of each branch)

  • If you frequently need to modelize branched networks mecaflux "pro 3D Networks" is better suited.

Start by recalling that a segment has a given flow rate which remains constant throughout its length. If there is a flow rate change (separation or junction of flows), there is change of segment. This implies that a connection must only be in the first or last position of a segment...

7 objects fittings are available in the tab "elements pressure losses", under the category "fittings":

Junction 135°
fitting head loss
 (plus or minus 20 degrees)
output 135°
fitting head loss
 (plus or minus 20 degrees)
input ou output 45°
fitting head loss
 (plus or minus 20 degrees)
Passage 135 °
fitting minor head losses
 (plus or minus 20 degrees)
Passage 45°
fitting minor head losses
 (plus or minus 20 degrees)
input ou output 90°
fitting minor head losses
 (plus or minus 20 degrees)
Passage 90°
fitting minor head losses
 (plus or minus 20 degrees)

Combinations of these 7 connections objects facility allows to model all 14 situations, separation and reunions fluid stream, gas or liquid:

reunions fluid stream
Separations fluid stream
1: Junction 135° + Passage 135 ° (fittings placed at the end of segment)
2: Junction 135° + Junction or output 45 (fittings placed at the beginning of segment)
pressure drop fitting = pressure drop fitting + pressure drop fitting
pressure drop fitting = pressure drop fitting + pressure drop fitting
3: output 135° + Junction or output 45° (fittings placed at the end of segment)
4: output 135° + Passage 135 °(fittings placed at the beginning of segment)
pressure drop fittings = pressure drop fittings + pressure drop fittings
pressure drop fittings = pressure drop fittings + pressure drop fittings
5: Junction or output45 + Passage 135 ° (fittings placed at the end of segment)
6: Junction or output 45 + Passage 135 °(fittings placed at the beginning of segment)
minor head loss fitting= minor head loss fitting + minor head loss fitting
minor head loss fitting = minor head loss fitting + minor head loss fitting
7:Junction 135° +Junction 135° (fittings placed at the end of segment
8: output 135° +output 135°(fittings placed at the beginning of segment
minor head losses fittings = minor head losses fittings + minor head losses fittings
minor head losses fittings = minor head losses fittings + minor head losses fittings
9: Junction or output 45 + Junction or output 45 (fittings placed at the end of segment)
10: Junction or output 45 + Jonction or output 45 (fittings placed at the beginning of segment)
minor losses = minor losses + minor losses
minor losses = minor losses + minor losses
11: Junction or output 90° + Passage 90° (fittings placed at the end of segment)
12: Junction or output 90° + Passage 90°(fittings placed at the beginning of segment)
hydraulic minor losses = hydraulic minor losses + hydraulic minor losses
hydraulic minor losses = hydraulic minor losses + hydraulic minor losses
13 : Junction or output 90° + Junction or output 90° (fittings placed at the end of segment)
14: Junction or output 90° + Junction or output 90° (fittings placed at the beginning of segment)
aeraulic minor head loss = aeraulic minor head loss + aeraulic minor head loss
aeraulic minor head loss = aeraulic minor head loss + aeraulic minor head loss

Modeling fittings is subject to three rules that evaluate all the cases encountered Exemple:

In reality the connection may have different diameters, to model these cases, insert cones, narrowing or widening to reduce the diameter to the fitting's size.

pressure drops fittings

Rule 1: 3 branches in direct contact with the fitting must have the same diameter.

tee or y fittings head loss pressure drop in junction and separation

Rule 2: The flow separation are always placed at the beginning of a section, the flow rate calculation is that of the section

tee or y fittings head loss pressure drop in junction and separation

If you follow these basic rules, calculations of pressure losses connecting sections, of all situations encountered is possible