Ultraflux UF 831, User Manual, Page: 36 / 109

36
NT UF 831 CO GB (b) / March 2014
5.4.3 "Description of section settings" menu
This menu is used to describe the section of the channel or the river.
1) Description of the section
For each chord, enter the elevation of the plane of the chord with regard
to the plane H0 and the two widths with regard to the plane W0. This
section can be defined in 20 points.
It is possible to define a distance to the right and to the left of the plane
W0.
2) Scale offset
3) Surface S0
When the bottom of the channel or the river is difficult to describe, both in terms of section and hydraulic
profile (for example if there is sand silting, pebbles, etc.), it can be estimated using parameter S0 which
defines a surface of the section in which the velocity is constant.
If this parameter is positive, the calculation of the flow adds this section to the hydraulic section (erosion of
the channel) and considers a constant fluid velocity equal to the lowest hydraulic section velocity.
If the value of S0 is negative, the value of S0 is deducted from the section and it is considered that so long
as the wetted section is smaller than S0, the flow is null (silting). The aim is to simulate a silting of the
channel.
The scale offset is the numerical value used to pass from
the section description reference system ("height reference
system") to the customer reference system ("level
reference system").
Level 0
(customer ref.
system)
Scale offset
(Height, Ultraflux
ref. system)
Level (water level gauge)