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authorDimitri Sokolyuk <demon@dim13.org>2009-05-11 00:27:49 +0000
committerDimitri Sokolyuk <demon@dim13.org>2009-05-11 00:27:49 +0000
commit0d4f43d355de79178b1142e9735902cf641670b6 (patch)
tree2ced2323f6351db2a51090b3fd13eb11f69ff53f /version_notes.txt
Xfoil 6.97
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+
+New features in XFOIL 6.1 (April 94)
+------------------------------------
+- An improved plot library libPlt.a is now used, courtesy of H. Youngren.
+ It allows resizing of the window, and plots are not erased upon overlay
+ by another window. A minor new nuisance is that the cursor does return
+ automatically to parent window after cursor input.
+
+- All LOGICAL*1 arrays have been eliminated (good riddance!).
+ CHARACTER strings are used instead. This was made possible
+ by the new plot library which accepts CHARACTER variables.
+
+- Mach number can now scale with 1/sqrt(CL) just like Reynolds number.
+
+- Numerous improvements have been made to the GDES, MDES, and QDES
+ facilities. Cursor-input Qspec(s) in QDES and MDES will now match
+ slopes where grafted into the current Qspec(s). Much fewer cursor
+ input points are now required. Same goes for the geometry contour
+ in GDES. The slope-matching can be disabled to get the cruddy old
+ way of doing things. The Qspec(s) plot in MDES and QDES now also
+ features an x/c grid overlay, making it more obvious where the
+ airfoil nose is among other things. The Qspec(s) plot in MDES
+ can also show Qspec(s) for more than one angle of attack, showing
+ the effect of any modification on off-design pressure distributions.
+ Symmetric airfoils can be much more easily designed now in MDES
+ and GDES.
+
+- Treament of non-unity airfoil chords is now much more consistent.
+ Clear distinctions are made between cartesian x,y and the airfoil
+ chord line-based x/c,y/c coordinates. GDES now has more general
+ airfoil positioning and scaling operations, and there is better
+ graphical info on the results of flap and camber change operations.
+
+- Cursor-selected blowups in QDES and MDES now produce exactly
+ the blowup region demarked, not some approximation thereto.
+ The GDES blowups are also more faithful, but must still be
+ approximate since they will not allow x/y distortion.
+
+- A second-order treatment of the amplification equation has been
+ implemented. As expected, It makes the solution less dependent
+ on the panel density. However, it also seems to be less robust.
+ For this reason, it has been implemented only as an option,
+ and the old first-order treatment has been retained as the
+ standard formulation. To switch between the two, a few labeled
+ code lines in SUBROUTINES AXSET, TRCHEK (in xblsys.f) simply
+ need to be commented/uncommented.
+
+
+New features in XFOIL 6.3 (Oct 94)
+----------------------------------
+- Nice grid overlays and axis limit set capabilities have been
+ added to the viscous variable plots (VPAR).
+
+- GDES has a number of new options, mainly for controlling
+ individual coordinate points.
+
+- Minor modifications have been made to the viscous formulation
+ to make it very nearly the same as the MSES 2.6 formulation,
+ except that XFOIL still uses a single-layer wake.
+
+
+New features in XFOIL 6.4 (Dec 94)
+----------------------------------
+- A modification to the e^n transition criterion has been added
+ to make it more reliable, especially for small Ncrit. The
+ default form for the amplification equation is now second-order.
+
+- Limiters have been put into most of the turbulent correlations
+ to make them automatically revert to their laminar form at small
+ Rtheta, including the dissipation coefficient for the wake.
+ As a result, XFOIL will now produce reasonable answers for
+ chord Reynolds numbers down to about 1000, which approaches
+ the Stokes-flow regime. The airfoils must be reasonably thin,
+ however, else there might not be any steady solution due to
+ vortex shedding. Thin indoor-model wing airfoils can be
+ predicted reasonably well, for example.
+
+
+New features in XFOIL 6.6 (March 96)
+------------------------------------
+- A fourth type of airfoil coordinate format is now recognized.
+ This is called a "labeled coordinate file", and is the same as
+ the plain format file, but includes the airfoil name string
+ on the first line, followed by the coordinates.
+
+- A completely new plot library is now used, courtesy of H.Youngren.
+ It supports color, PostScript echo on demand (instead of the arcane
+ hardcopy-toggle approach of the previous plot library), lowercase
+ fonts, LaTex-like math fonts (in annotation menu), etc. This
+ one plot library is used for all machines.
+
+- Color is now used in many of the screen plots, but only where
+ it actually helps to see what's happening. Color is NOT used
+ for ornamental purposes. Hence, many of the plots or parts
+ of plots are still monochrome. Color PostScript can be output
+ by setting the IDEVRP flag appropriately (see SUBR. INIT).
+
+- The "!" command is now understood by OPER,GDES,MDES, and QDES.
+ This simply repeats the last valid command, and saves typing
+ in repetitive-command situtations.
+
+
+New features in XFOIL 6.8 (August 96)
+-------------------------------------
+
+- The matrix-conditioning problem which appears in sharp-TE cases
+ with large TE angles has been significantly alleviated. A more
+ forgiving TE vorticity extrapolation scheme is used.
+
+- GDES now displays useful geometric info along with the airfoil shape.
+
+- Color is now used in most of the plots to aid visualization.
+ The plot can be customized with a number of plot options set
+ in the PLOP menu. Portrait orientation plots can now be
+ generated if desired.
+
+- Almost all commands which result in prompted input can now
+ be given arguments with the input values. For example,
+ instead of
+
+ .OPERi c> alfa
+
+ Enter angle of attack (deg) r> 3.5
+
+
+ one can simply type
+
+ .OPERi c> alfa 3.5
+
+
+ which suppresses the prompt and just takes the "3.5" as its input.
+ This also works for multiple-input commands. For example:
+
+ .OPERi c> aseq 0 10 0.5
+
+ does the usual alpha-sequence calculation with no further prompts.
+ This also works for filenames. For example:
+
+ XFOIL c> load e387.dat
+
+
+
+New and final(!) features in XFOIL 6.9 (February 00)
+----------------------------------------------------
+
+- Finally fixed that annoying screwy behavior with sharp trailing edges.
+ Instead of the vorticity extrapolation scheme, the chordwise velocity
+ at an internal point near the TE is set to zero to enforce solution
+ regularity there (this complements the Kutta condition, which controls
+ the normal velocity component). This additional internal point is
+ placed 1/10 of the smallest panel length ahead of the TE. The results
+ are extremely insensitive to its exact location.
+
+- Multiple airfoil versions and associated polars can now be stored
+ inside XFOIL. The polars and airfoils are managed in OPER.
+ Having the polars and airfoils online reduces the amount of
+ airfoil read/writes and mental bookkeeping which was required
+ in previous XFOIL versions which had only one airfoil stored.
+ Quite a few new commands have been added to OPER to deal with
+ this additional stuff, but everything more or less defaults to
+ the previous conventions if only one airfoil is kept stored.
+ The session.txt file has a sample session with multiple polars.
+
+- Airfoil interpolation can now be performed with the INTE
+ command at top level.
+
+- A bunch of Youngren's camber/thickness modification stuff has
+ been incorporated into GDES.
+
+- Most of the interactive modification displays now include
+ "Erase" and "Done" keys in addition to the "Abort" key.
+ These can also be activated just by typing "e", "d", or "a"
+ rather than by clicking on the button. The Erase key
+ deletes the previous click entry (or previous entries if done
+ repeatedly). The Done key terminates input. In previous versions
+ this was done by three identical clicks, which was sometimes
+ difficult to do.
+
+
+XFOIL 6.91 (December 00) (first web release)
+--------------------------------------------
+
+- Renamed "Gamma" to "Q" in the QDES and MDES menus. This gives
+ somewhat more obvious relation to "Qspec".
+
+- The PREM command has been added to the OPER menu. This allows
+ removing individual points from stored polars.
+
+- The CADD command has been added to the GDES menu. This adds
+ new points into the buffer airfoil at excessive panel corners.
+ The new points are interpolated using a uniform-parameter spline,
+ which gives much smoother shapes near the leading edges of
+ Selig and Eppler airfoils, whose point spacing at the leading edge
+ is usually not suitable for Xfoil's arclength-parameter spline.
+ For example, the load sequence...
+
+ LOAD s6063.dat
+ GDES
+ CADD
+ <return> (accept default inputs)
+ <return>
+ <return>
+ <return>
+ PANE (generate new paneling using smoother buffer airfoil)
+
+ will give a much smoother paneled airfoil than the more direct...
+
+ LOAD s6063.dat
+ PANE
+
+
+XFOIL 6.92 (January 01)
+-----------------------
+
+- Fixed the PSOR command. Giving "0" for the polar index now sorts all
+ the polars as advertised. Previously, this deleted all the polars (oops).
+
+- Fixed PPLO command. Giving multiple individual polar indices now plots only
+ those polars as advertised. Previously, all polars were always plotted.
+
+- Added DUMP and OVER commands to the VPLO menu. This allows comparing
+ viscous variable distributions between different airfoils and/or
+ different operating points.
+
+- Added BLC, BLWT commands to OPER menu. These allow plotting of boundary
+ layer velocity profiles on airfoil in Cp vs x plot. Gives more insight
+ into what the flow is doing than just the displacement body shape.
+
+
+XFOIL 6.93 (18 January 01) HHY
+-----------------------
+
+- Improvements to polar plotting for XFOIL and PPLOT. Many fixes to read
+ XFOIL and non-XFOIL polar files. Routine polplt.f overhauled to eliminate
+ numerous cruftious hacks and long-standing polar plot problems.
+
+- PPLOT improvements to add options and de-obfuscate menu choices. Tweaks to
+ make pplot.f work with new polplt.f changes. More robust than previous
+ version - now reads MSES and old XFOIL format polar files.
+
+- Fixed CAMB options for INPP and MODP. Plotting hack for INPP fixed to
+ to properly display grid. MODP problems (improper scaling of user points)
+ fixed.
+
+- Changed ASKR and ASKI and all relevant calls. Now ASKR or ASKI calls do
+ not modify variable passed in if read line is blank (i.e. user just inputs
+ a <cr>). Lines to set reasonable defaults added throughout where these
+ routines read temp variables or variables not stored in globals. This affects
+ mostly routines in GDES.
+
+- Latest plotlib (version 4.44) included. This version has several bug fixes
+ and adds capability to write separate postscript files for each plot (if you
+ ask for this). Also default background color is now black. User must now
+ specifically ask for white background by setting environment variable
+ "XPLOT11_BACKGROUND white". This is done for csh/tcsh and bash using
+ csh: setenv XPLOT11_BACKGROUND white
+ bash: export XPLOT11_BACKGROUND=white
+
+- Bug in dplot.f (LGUI declaration) and funky format (A,I) in xplots.f changed
+ to work with g77.
+
+
+XFOIL 6.93 (March,April '01) MD's additions
+-------------------------------------------
+
+- Made CM axis line up with CL-axis tics in polplt.f .
+
+- Changed Xplot11 to start cursor at previous location rather than at
+ center of plot window. Makes repetitive mouse input much more pleasant.
+
+- Checks for excessive panel angle in input coordinates, and prints
+ suggested corrective action if indicated.
+
+
+XFOIL 6.94 (Nov '01)
+--------------------
+
+- Put in alternative short versions of most commonly used commands
+ Examples:
+ "ALFA" and "A" are now equivalent commands in OPER
+ "EXEC" and "X" are now equivalent commands in MDES,QDES,GDES
+
+- Added a number of minor widgets and doodads
+
+- Fixed PostScript output semi-bug (wrong number of tokens after %%Page)
+
+
+XFOIL 6.95 (Feb '03)
+---------------------
+
+- ITER command in OPER now accepts a numeric argument like the other commands
+
+- Inviscid polar accumulation now permitted
+
+- Improved ADDP and MOVP in GDES, allowing optional keyboard x,y entry
+
+- Added I,O,P key functions in cursor-modification windows,
+ allowing zooming and panning without exiting the window
+
+- Added individual-frequency plotting to A/Ao plot in VPLO.
+ Requires Orr-Sommerfeld database in compatible binary form.
+ This is built in the new directory orrs/
+
+
+XFOIL 6.96 (Jan '05)
+---------------------
+
+- Added a bunch of features to PPLOT.
+ Power coefficient polars and aircraft polars can now be plotted.
+
+- Added graphic enable/disable flag to PLOP sub-menu.
+ Allows suppression of graphics output for batch execution.
+
+- Increased default number of panel nodes from 140 to 160
+
+- Increased default iteration limit from 10 to 20
+
+- Changed VACCEL logic to make it independent of airfoil size
+ (previously it assumed that chord was comparable to unity)
+
+- Added BEND command to GDES
+
+- Airfoils are now written out in 7 significant digits using G-format.
+ This should prevent introduction of noise with very fine point spacings.
+
+
+XFOIL 6.96 (Nov '05) UPDATE
+----------------------------
+
+- Fixed compilation problem in PPLOT (no change to XFOIL)
+
+
+XFOIL 6.97 (Dec '06)
+--------------------
+
+- Tabs in coordinate files are now treated as spaces
+ (no longer cause read errors)
+
+- Increased wake array limit to allow up to 360 surface nodes.
+
+- Changed default surface plot colors to blue and red.
+ The previous yellow was sometimes hard to see on white backgrounds.
+
+- Streamlined and extended some PPLOT features.
+
+- Added actuator-disk parameters to polar files to be compatible with MSES.
+ (these parameters are not significant to XFOIL)
+
+- Improved BEND output formatting, with separated solid and skin parameters.
+
+- Fixed the processing of data input via INPC and INPP,
+ in the ..CAMB submenu in .GDES
+
+
+XFOIL 6.97 (Dec '07) UPDATE
+---------------------------
+
+- Fixed PNAM command in OPER menu.
+
+- Eliminated yellow color for polar plots (both in PPLOT and XFOIL).
+ This was difficult to see on white backgrounds.
+
+
+XFOIL 6.97 (Apr '08) UPDATE 2
+-----------------------------
+
+- Fixed a few undefined references in some of the plot
+ post-processing calculations. Compressibility effects
+ were not being properly calculated.
+
+
+