FAST User's Guide xii Last updated on August 12, 2005 for version 6.0
ADAMS user-created dynamic-link-library (DLL).
This is because ADAMS datasets generated using
FAST v5.1 must be simulated with an ADAMS user-
created DLL compiled using the source files from
A2AD v12.17. All of the new features for FAST v5.1
listed above are also available in the FAST-to-ADAMS
preprocessor.
U
PGRADING TO
FAST
V
5.0
FROM V
4.4
FAST v5.0 contains a major expansion in the
range of turbine configurations available relative to
those available in FAST v4.4. This section describes
how to update input files created previously for FAST
v4.4 so that they are compatible with FAST v5.0. New
users can skip to the section entitled Using This
Manual.
New to FAST v5.0 is the availability of a lateral
offset and skew angle of the rotor shaft, rotor-furling,
tail-furling, and tail inertia and aerodynamics. These
new features support the analysis of most small wind
turbine configurations. A few new mass and inertia
terms are also available for conventional turbine
configurations including a yaw bearing point mass, a
lateral offset for the nacelle mass, and a hub inertia for
3-bladed rotors (the hub inertia was previously
available only for 2-bladed rotor configurations).
While upgrading FAST, we tried to minimize the
number of changes to the input files as a courtesy to
our users; nevertheless, some changes were
unavoidable. Updating to FAST v5.0 from v4.4
requires a few modifications to FAST’s primary and
ADAMS-specific input files, even if you want to keep
your turbine model configuration unchanged.
Additionally, to take advantage of FAST’s new model
configuration properties for small wind turbines, a new
file of inputs must be assembled. Detailed information
on the new features and associated inputs are presented
throughout this manual where appropriate. In
particular, a description of the input file for specifying
additional model properties for a furling turbine is
provided in Table 13.
The changes to the primary input file are as
follows (in the order they appear in the file):
• Remove input TiltDOF.
• Remove input NacTilt.
• Replace inputs ParaDNM and PerpDNM
with inputs NacCMxn, NacCMyn, and
NacCMzn. These three new inputs define the
distance from the tower-top to the nacelle
mass center in the downwind, lateral, and
vertical directions, respectively. This is in
contrast to how ParaDNM and PerpDNM
previously located the nacelle mass center
relative to the rotor shaft.
• Add input ShftTilt between inputs TwrRBHt
and Delta3. ShftTilt defines the rotor shaft
tilt angle, replacing what used to be input
NacTilt.
• Add input YawBrMass before NacMass.
YawBrMass defines the point mass of the
yaw bearing.
• Remove input NacTIner.
• Replace the entire nacelle-tilt section, which
includes the header plus inputs TiltSpr,
TiltDamp, TiltSStP, TiltHStP, TiltSSSp, and
TiltHSSp, with a furling section, which
includes a header plus inputs Furling and
FurlFile. Furling is a flag used to tell FAST
whether or not to read in an additional file of
inputs for defining the model configuration of
a furling turbine. FurlFile is the name of this
file.
The changes to the ADAMS-specific input file are
as follows (in the order they appear in the file):
• Add input LSSLength between inputs
HSSLength and GenRad. LSSLength
defines the length of the low-speed shaft
cylinder used for LSS graphical output in
ADAMS. This is in contrast to how the LSS
previously extended from the hub to the yaw
axis.
• Remove inputs TetPnLngth and
TeetPinRad. These inputs were deemed
unnecessary graphical output in ADAMS.
• Add input BoomRad after input
ThkOvrChrd at the end of the file.
BoomRad defines the radius of the tail boom
cylinder used for tail boom graphical output in
ADAMS.
If you want to leave your turbine model
configuration unchanged when converting to FAST
v5.0, use the following equivalency relationships when
defining the new inputs from the old, now obsolete,
inputs:
NacCMxn = ParaDNM • COS( NacTilt ) -
PerpDNM • SIN( NacTilt )
NacCMyn = 0.0
NacCMzn = ParaDNM • SIN( NacTilt ) +
PerpDNM • COS( NacTilt ) + Twr2Shft
ShftTilt = NacTilt