Frequently Asked Questions about Polar Explorer
A You can run Polar Explorer directly on Windows 3.1 to Windows XP.
A Although at the time of this writing I haven't tested this, I believe that you can do this through DOSBox DOS-emulator. You can download free DOSBox for Mac OS X, Linux and a bunch of other operating systems from http://dosbox.sourceforge.net/download.php?main=1
A Although Windows (especially XP)
doesn't support DOS graphics mode in a window natively, there is a way to do
this by running Polar Explorer through DOSBox DOS-emulator. You can
download free DOSBox from
A If you are running Polar Explorer
under Windows 98 or earlier (with or without DOSBox) you can use
<Shift>+<Print Screen> key combination or <Alt>+<Print Screen> when you have
the desired graph on screen. This will send the screen graphics into the
Windows clipboard, from which you can then insert it into any image editing
program (such as MS Paint) or directly into Word.
A You can do this by selecting Options | Force mono graph (Yes) and then Options | Colors | Graph | Inverse.
A In order to do this, do a Table print to a text file (selected under Printing options). Then import the table from the text file into Excel and use it to recreate the graph.
A A glider is defined by a few geometric parameters (e.g. wing span, wing area), aerodynamic parameters (e.g. aspect ratio correction factor), and anywhere between 3 and 30 points on the polar curve. The polar curve can be a speed - sink polar, or one of 3 different variations of a CL-CD (lift coefficient - drag coefficient) polar. Once entered, the polar curve can be converted from one type to any other.
A Any combination of supported units of measure is permitted (Options | Units). For instance, you can enter speed in m/s and sink in fpm.
A Unit conversion in Polar Explorer is very simple, and you can convert glider data from one set of units to any other set of units through Options | Units. The results of the conversion are instantly shown on the screen.
A It draws a smooth piece-wise double parabolic curve through every V-W or CL-CD point on the polar curve.
A Polar Explorer goes to great lengths to accommodate and correctly process almost any possible and impossible glider polar. If a polar has dents, knees or bulges, Polar Explorer will take them all into account when calculating the speed-to-fly, cross country speed, circling performance, etc.
A For instance, if you have a table with 20 points on a speed polar, it should take 5-10 minutes to enter the points and iron out unwanted irregularities.
A No. The data defining a glider can be stored in a glider library. One library can store up to 500 gliders, and you can use more than one library.
A It already comes with a fairly large library of polars (see Polar_Explorer_Short_Guide.pdf). Most of the polars are based on flight measurements by DLR institute in Germany and Richard Johnson in U.S.A. There are also some factory polars.
A Any glider in a library can be: renamed, edited, deleted from the library and copied to another library. (The same can be done to any sheet in the sheet library.)
A It can calculate the following performance curves, shown here grouped into five categories:
A Any combination of the following parameters can be varied:
A It normally calculates only a
certain number of discreet points on the performance curves, and then draws
a smooth curve through those points.
A Graph display precision can be set
separately to low, medium, high, or straight-line. It is independent of the
calculation precision, and it determines how the program shows the curves on
the screen. When the precision is higher, the performance curves are drawn
more accurately, and therefore slower.
A Horizontal speed (V) and vertical speed (W) can be both shown either as EAS or as TAS by setting the V equivalent and W equivalent parameters on the main sheet to Yes for EAS or No for TAS.
A The results can be shown in any combination of units that are available in the Options | Units window.
A Polar Explorer approximates the Reynolds number influence on the viscous drag coefficient through the Reynolds number exponent that is a part of glider definition data.
A It is defined by setting the values of pressure and temperature at zero altitude, and giving the temperature at up to 5 more levels. The laps rate in each segment is assumed constant. The gas constant for air can also be modified to simulate the effect of humidity.
A Polar Explorer can calculate circling performance in 4 different modes:
A Polar Explorer first calculates the optimum circling performance (see above). Then, it determines the circling radius for which the maximum rate of climb is achieved. Polar Explorer does this for different thermal strengths, so the climb rate varies from 0 to the maximum desired climb rate.
A It calculates it by varying climb rate, or by varying thermal strength and calculating the corresponding climb rate. In addition to altitude, glider performance and wing loading, it takes into account horizontal wind, updraft movement (drift), vertical movement of the airmass between the updrafts and the McCready speed ring setting.
A You can use Polar Explorer to get the following information:
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