New Version of the Free RASAero II Software (Version 1.0.2.0) Released To All:
A new version of the free RASAero II software (Version 1.0.2.0) has been
released, and is available for download from the RASAero web site at
www.rasaero.com . A link to the new version of the RASAero II software is on
the home page, or click on the RASAero II Software and RASAero II Users Manual
buttons on the left-hand side of the home page to access the web pages for
downloading the new version of the software, and downloading the updated users
manual. Note that while it is always important to upgrade to the latest
version of any software, in this particular case there were errors in the nose
cone wave drag models for LV-Haack, parabolic, and elliptical nose cones, that
have now been corrected. If you used any of those nose cones on your rockets,
you'll need to re-run the rockets. There were no errors in the nose cone wave
drag models for tangent ogive, Von Karman ogive, conical, and power law nose
cones. The updates to RASAero II in the Version 1.0.2.0 of the software are
listed below. RASAero II Version 1.0.2.0 – Release Date May 22, 2019
Corrected errors in the nose cone wave drag models for LV-Haack, parabolic, and
elliptical nose cones. There were no errors in the nose cone wave drag models
for tangent ogive, Von Karman ogive, conical, and power law nose cones. Nose
cone wave drag occurs at transonic, supersonic, and hypersonic Mach numbers.
Added the ability to enter nested upper stages; where the upper stage motor
extends beyond the bottom of the upper stage and slides into the front of the
booster stage. Added new protuberance drag models (for missile raceways,
camera shrouds, fin brackets, etc.); streamlined no base drag, streamlined with
base drag, and inclined flat plate. Combined protuberance drags; rail guide,
launch lug, launch shoe, streamlined no base drag, streamlined with base drag,
inclined flat plate; into one combined protuberance drag coefficient (CD)
output. Added option to the existing capability to export tabular output data
from the Flight Simulation to an Excel (.CSV) output file, where rather than
having the data exported to the file in increments of every 0.01 sec, the user
can select every 0.01 sec, 0.10 sec, 0.50 sec, or 1.0 sec. (The Flight
Simulation is still run with a time step of 0.01 sec, the data is just exported
in larger time steps.) Note that the Aerodynamic Plots also has the existing
capability to export aerodynamic tabular output data to an Excel (.CSV) output
file. Corrected error in the first motion on the launch rail when the initial
thrust was lower than weight. Rocket did not slide backwards on the rail, but
negative acceleration was built up which had to be unwound into positive
acceleration before the rocket would begin to move up the rail. Made further
improvements in the extensions to the power-on base drag model for very large
nozzle exit diameters at supersonic and hypersonic Mach numbers, with the
nozzle exit area filling a large portion of the rocket base area, for more
accurate power-on CD predictions for first and second stages of satellite
launch vehicles. No change in the power-on CD for most model, high power, and
amateur rockets. Made mods to the Rogers Modified Barrowman Method nose cone
subsonic potential CNAlpha and Center of Pressure (CP) equations for increased
accuracy. In the Rogers Modified Barrowman Method the Nose Cone and the body
tube which follows the nose cone are treated aerodynamically as a single unit
for subsonic potential CNAlpha and CP. Made mods to the Rogers Modified
Barrowman Method expansion section subsonic potential CNAlpha for increased
accuracy. No mods were made to the Rogers Modified Barrowman Method expansion
section subsonic potential CP. Corrected error in the Barrowman Method
subsonic CP for LV-Haack nose cones. For rounded and square airfoils with All
Turbulent Flow corrected errors in the fin supersonic and hypersonic friction
drag. Modified line-up of print columns in subsonic, transonic, and supersonic
and hypersonic print outputs. The further improvements in the extensions to
the power-on base drag model for very large nozzle exit diameters at supersonic
and hypersonic Mach numbers came about from RASAero II being used to generate
aero data for flight simulations for orbital launch vehicles for
undergraduate/graduate student studies and for proposed small space launch
vehicles. Launch vehicles, in particular the second stages of launch vehicles,
can have very large nozzle exit areas that fill most of the base area of the
first or second stage. For a launch vehicle on an ascent trajectory to orbit
almost all of the flight within the atmosphere is "power-on" relative to the
drag coefficients (CD’s) used for the launch vehicle. The RASAero II authors,
Charles E. (Chuck) Rogers and David (Coop) Cooper, are always looking for high
power rocket and amateur rocket flight data to compare the RASAero II altitude
predictions against to further develop and improve the RASAero II aerodynamic
prediction and altitude prediction models. The flight data and rocket
information can be sent to the e-mail address below.Additional information on
the RASAero II software can be found on the RASAero web site at www.rasaero.com
. The RASAero II authors, Charles E. (Chuck) Rogers and David (Coop) Cooper can
be contacted at CRogers168@xxxxxxx .Chuck RogersRogers Aeroscience
