This is the AVL source deck avl-dist, 


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AVL V2.5, dated 8-5-96                HHY

This source has been updated to match the Xplot10-4.3 plot library.

This version has a number of fixes over older versions, including:

  Bug fix on chord angles on tapered, twisted panels.

  Bug fix on hinge line vector to make both real and image hinge rotations
  in the same sense.

  The user can specify a CL or CM with "cl" or "cm" rather than 999. or -999 

  The Mach number is now a menu item (regenerates matrices for each new Mach)

  The getvm.f module now dumps the shear (Vz) and moment Myy for each panel.

This version does not include any drag polar interpolation or the INDRAG 
drag calculation.  See avl-polartrp for these...




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AVL 2.70, dated 2-24-97               HHY

Massive rewrite of AVL:

Completely new geometry plotting with many display options.
  Fixes to hidden line routines.
  Eliminated old lame loading plots
  Updated Trefftz plane plots

Auto-image generation in main Option menu that generates an image half 
for cases with IYsym=1.

Matrix solution completely revised to take full advantage of symmetry for 4x
increase in speed for symmetric cases where the image side is generated with 
the auto-image option.

Section viscous drag can now be included and summed into forces.
A CD(CL) polar can be defined for each section based on 6 pairs of CL,CD
points in the polar.

Angular rates can be specified in either Stabilty axes or Body axes.

Forces can be resolved in NASA Stability axes or Geometric Stability axes.
Options are added to select the axes used for rates and forces.

Comments starting with ! are recognized in the input deck to make datasets
more self documenting.

The ambiguity of what SREF refers to is resolved by making SREF refer to both 
sides of a symmetric configuration (IYsym=1) rather than half the total area
as used in previous AVL versions.  NOTE THAT YOU WILL HAVE TO DOUBLE THE SREF
FOR OLDER DATASETS with IYSYM=1.


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AVL 2.76, dated 5-4-98               HHY

Fixes and changes motivated by Ming Chang @ LMSW 
  Added CMLE for strip to get hinge moments
  changes to output routines for printed data FS strip,FT total,FE element
  updated selection menu for surfaces
  fixed CDvisc linearization with dCDv/dCL term from CDCL routine


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AVL 2.77, dated 5-22-98               HHY

Several problems were noted with winglets and the displayed surface forces
in local reference coordinates.  This prompted a bunch of changes and updates:

Rehash of forces calculation in AERO 
  started going to calculating body axes forces and then transforming to
    local systems using direction dot products (less confusing)
  added locally referenced surface CL,CD,CMLE
  new treatment for calculating local CL,CD for strips & surfaces
  Changed surface CMLE calculation 
  fixed (properly) strip CN,CA to properly reflect X chordline (may want to 
    add incidence to the axial direction eventually)
  strip CD(CL) fixed to use proper local CL rather than CL component 
    in global system (affected winglets and dihedraled surfaces)

New output routine to separate surface by surface forces listing from 
the total forces output.  Added print flags for controling output print from
these new options. 

Added option of displaying current hinge settings using ? input on command
line when entering hinge data.

Biggish changes to aplotccl.f to plot Trefftz data vs either Y or Z
  added user-specified plot limits
  fixed bug for -Y scale on plotting (axis was improperly shifted)

Changed colors a bit in aplotvl.f to accentuate loadings better in plots.

Note that there appears to be compiler bug using g77-0.5.21 on hidden.f, you 
might want to use f2c to compile this routine to avoid this bug (which appears
as random line segments appearing in foreground surfaces from background 
lines.  None of the other compilers appear to have this problem...


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AVL 2.78, dated 7-5-98               MD

Fixed a bug in the stability-derivative calculation.

Hinge angles can now be changed either directly as before, or indirectly
by perturbing the control variables...

 delta_a     delta_t
 delta_e     delta_a
 delta_r     delta_f

which influence the hinge angles via the new "CONTROL" keyword
declaration for a surface.  See the avl.doc manual for details.

Eliminated the SLOPE keyword capability, which has never been 
used as far as I can tell.

Added control-deflection derivatives to the stability-derivative output,
so that quantities like Cmde = d(Cm)/d(delta_e) are displayed.
It is no longer necessary to generate these by manually perturbing
each control surface and finite-differencing the forces.

Added design variables, which currently represent virtual twists
added to one or more sections.  Sensitivities of CL, CD, etc
to these design variables can be displayed.  The intent is to
give some guidance to span load optimization.

Added hot-key rotation capability to the Geometry plot menu.


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AVL 2.81   7 June 03                MD

Major revisions for new 2.8x series...

Changed CONTROL definitions to be associated with sections.
These modify the camberline via control variables defined
entirely by the used.  The built-in control variables delta_a,
delta_e, etc., have been eliminated.  The user specifies the
name of each control variable.

General trimming capability has been added, including the ability
to drive control variables to achieve trim.  Constraints are
selected from a general sub-menu.

Hinge stuff has been removed, since it's somewhat redundant
with the new control stuff -- putting the control hingeline 
at 0% chord will rotate the whole surface just like the previous
hinge feature.

Design parameters are now input one per DESIGN declaration,
and the user can specify the design parameter name.

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AVL 2.82  (minor tweaks on 2.81)    13 Jun 03              MD

Re-organized some of the menus.

Fixed a few typos in the menus, the user manual, and the session.txt file.


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AVL 3.00   22 Sep 03                MD

Very major revision for 3.0x series...

Added finite core radius option to mostly eliminate hassles 
with alignment of trailing vortices with downstream surface paneling.

Forces are computed not only on the bound vortex legs, but also
on the parts of trailing legs which lie on the physical surface.
This mainly affects the rolling moment due to sideslip.

Added body modeling via source+doublet lines.  These affect
the vortex lattice circulations via their volume velocity fields.
They also see direct forces and moments via slender-body theory.
It's not yet clear how useful this modeling capability will be.

Errors in the input file will now produce much better diagnostic
messages than before.  The offending line and line number are displayed.

Added general operating state calculation interface.
Variables consisting of alpha, beta, rotation rates, and control deflections
can be either imposed explicitly, or computed implicitly via imposed force
or moment coefficients.  Trim states can thus be easily computed.

Multiple operating run cases can be defined and saved to a file
for later recall.  This allows easy re-running of cases 
after a geometry modification, say.

Geometry plot has been improved, with x,y,z space axes added.


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AVL 3.01  10 Jan 04              MD

Added a flight dynamics mode calculation and display module.
This requires mass and inertia data, which is read from a file,
or input manually.  Using the mass file also provides other 
necessary dimensional data, such as the air density and the 
gravitational acceleration, and allows declaration of working
units which can differ from those used to define the geometry 
and masses.

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AVL 3.11  6 May 04                MD

OPER now allows easy setup of trim states in level or banked 
horizontal flight (C1 sub-menu), or in planar looping flight 
(C2 sub-menu).

Added multiple-case parameter input capability to the C1,C2 sub-menus
in OPER, and the M sub-menu in MODE.  Multiple cases are targeted
by typing the parameter command twice (see manual).

Additional parameters can be varied in root-locus sweeps, in particular
the reference (CG) location, and the mass and inertias.

Added camera pan/no-pan option to the eigenmode viewer in MODE.

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AVL 3.13  21 May 04                MD

Added the optional CLAF surface-section parameter, which
allows changing the effective section dcl/da to something
other than 2 pi to better represent thick airfoils.
