# 22/4/2008 - Ripepi Matteo
#
# MBDyn model of the HALE aircraft wing
#
# Data taken from:
#
# Journal of Fluids and Structures (2001) 15, 107-132
# LIMIT-CYCLE OSCILLATIONS IN HIGH-ASPECT-RATIO WINGS
# M. J. Patil, D. H. Hodges, C. E. S. Cesnik
# DATA
#
# Half-span 16 m
# Chord 1 m
# Mass per unit length 0.75 kg/m
# Moment of inertia (50% chord) 0.1 kgm
# Span-wise elastic axis 50% chord
# Center of gravity 50% chord
# Bending rigidity 2x10^4 Nm2
# Torsional rigidity 1x10^4 Nm2
# Bending rigidity (chordwise) 4x10^6 Nm2
# Flight condition
# Altitude 20 km
# Density of air 0.0889 kg/m3
# preset data
include: "wing.set";
begin: data;
problem: initial value;
end: data;
begin: initial value;
initial time: 0.;
final time: 30.;
time step: 1e-2;
tolerance: 1e-3;
max iterations: 70;
derivatives tolerance: 10e0;
derivatives max iterations: 200;
derivatives coefficient: 1e-3;
linear solver: naive, colamd, mt, 1, pivot factor, 1e-8;
nonlinear solver: newton raphson, modified, 10;
eigenanalysis: 50., parameter, 1.e-6,
output matrices, output eigenvectors;
threads: disable;
method: bdf;
end: initial value;
begin: control data;
structural nodes:
+2*N_beam + 1
;
joints:
+1 # ground clamp
;
rigid bodies:
+3*N_beam
;
beams:
+N_beam
;
forces:
+1 # engine
;
aerodynamic elements:
+N_beam
;
gravity;
air properties;
end: control data;
include: "wing.ref";
begin: nodes;
# ground
structural: RF_wing_root, dynamic,
reference, RF_wing_root, null,
reference, RF_wing_root, eye,
reference, RF_wing_root, null,
reference, RF_wing_root, null;
# wing
include: "wing.nod";
end: nodes;
begin: elements;
gravity:
0., 0., -1,
cosine, 0., pi/Tstart, gg/2., half, 0.;
# ground clamp
joint: RF_wing_root, clamp, RF_wing_root, node, node;
# wing structural elements
include: "struct.elm";
# density and celerity of sound
air properties: density, sound_celerity,
0., -1., 0.,
cosine, 0., pi/Tstart, Vinf/2., half, 0.;
# wing aerodynamic elements
include: "aero.elm";
# engines' force
force: 1, follower,
tip,
position, +0.0, +0.0, +0.0,
reference, RF_wing_root, 0.,1.,0.,
cosine, 0., pi/Tstart, Teng/2., half, 0.;
inertia: 1,
body, all;
end: elements;