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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, Chuck Rogers and David "Coop" Cooper, are always looking for high power rocket and Tripoli Research/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 [email protected] .
Charles E. (Chuck)Rogers
Rogers Aeroscience
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, Chuck Rogers and David "Coop" Cooper, are always looking for high power rocket and Tripoli Research/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 [email protected] .
Charles E. (Chuck)Rogers
Rogers Aeroscience
