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MAN B&W 17.05
As the deflection shape for the H�type <strong>is</strong> equal
for each cylinder the N th order H�type guide force
moment for an N�cylinder engine with regular firing
order <strong>is</strong>:
N x M H(one cylinder)
For modelling purposes the size of the forces in
the force couple <strong>is</strong>:
Force = M H /L [kN]
where L <strong>is</strong> the d<strong>is</strong>tance between crankshaft level
and the middle position of the crosshead guide
(i.e. the length of the connecting rod.)
As the interaction between engine and hull <strong>is</strong> at
the engine seating and the top bracing positions,
th<strong>is</strong> force couple may alternatively be applied in
those positions with a vertical d<strong>is</strong>tance of (L Z ).
Then the force can be calculated as:
Force Z = M H /L Z [kN]
Any other vertical d<strong>is</strong>tance may be applied, so as
to accomodate the actual hull (FEM) model.
The force couple may be d<strong>is</strong>tributed at any
number of points in the longitudinal direction. A
reasonable way of dividing the couple <strong>is</strong> by the
number of top bracing and then applying the forces
at those points.
Force Z, one point = Force Z, total /N top bracing, total [kN]
X�type Guide Force Moment (M X )
The X�type guide force moment <strong>is</strong> calculated
based on the same force couple as described
above. However as the deflection shape <strong>is</strong> tw<strong>is</strong>ting
the engine each cylinder unit does not contribute
with an equal amount. The centre units do not
contribute very much whereas the units at each
end contributes much.
A so�called ‘Bi�moment’ can be calculated (Fig.
17.05.01):
‘Bi�moment’ = Σ [force�couple(cyl.X) x d<strong>is</strong>tX]
in kNm 2
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The X�type guide force moment <strong>is</strong> then defined
as:
M X = ‘Bi�Moment’/L kNm
For modelling purpose the size of the four (4) forces
can be calculated:
Force = M X /L X [kN]
where:
L X <strong>is</strong> the horizontal length between ‘force points’
Similar to the situation for the H�type guide force
moment, the forces may be applied in positions
suitable for the FEM model of the hull. Thus the
forces may be referred to another vertical level L Z
above crankshaft centre line. These forces can be
calculated as follows:
Force = Z, one point M _____ x L x
L x L [kN]
In order to calculate the forces it <strong>is</strong> necessary
to know the lengths of the connecting rods = L,
which are:
Engine Type L in mm
K108ME�C6 ,400
K98ME6/7 ,220
K98ME�C6/7 ,090
S90ME�C7/8 ,270
K90ME9 , 20
K90ME-C9 ,120
K90ME�C6 ,159
S80ME�C9 ,450
S80ME�C7/8 ,280
K80ME�C9 2,975
K80ME�C6 2,920
S70ME-C7/8 2,870
S70ME�GI7/8 2,870
Engine Type L in mm
L70ME�C7/8 2,660
S65ME�C8 2,7 0
S65ME�GI8 2,7 0
S60ME�C7/8 2,460
S60ME�GI7/8 2,460
L60ME�C7/8 2,280
S50ME�C7/8 2,050
S50ME-B9 2,114
S50ME-B8 2,050
S40ME-B9 1,770
S 5ME-B9 1,550
MAN B&W ME/ME-B/ME�C/ME�GI engines 198 45 17�0.5
MAN Diesel