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Nozzle 3.7
Example: External shock pattern for an
overexpanded SSME rocket nozzle.
Nozzle 3.7
is a one-dimensional isentropic with cross-sectional area variation,
compressible flow computer program for the analysis of converging-diverging
nozzles. Nozzle internal flow may be entirely subsonic, entirely
supersonic or a combination of subsonic and supersonic
 including
shock waves in the diverging part of the nozzle. Shock waves are
clearly identified as vertical red lines on all plots. The cross-sectional
shape in the axial direction of the nozzle is specified by selecting
from five standard nozzle types or by defining nozzle geometry
using the Free-Form nozzle geometry method. Nozzle plots color
contours of pressure ratio, temperature ratio, density ratio
and Mach number and has a slider bar that displays real-time values
of all nozzle flow properties. New in this version is the ability
to determine shock-angle, jet-angle (plume-angle) and Mach number
for axisymmetric and two-dimensional nozzles in the region near
the lip for underexpanded and overexpanded flow.
The converging-diverging nozzle
featured in the new AeroRocket supersonic blow-down wind tunnel
was designed
using
Nozzle 3.7 applying the concept of a normal shock
diffuser. Finally, use
AeroRocketCAD to generate Nozzle 3.7 and VisualCFD shapes
from AutoCAD
DXF geometry.
More ...
VisualCFD 4.1 Example: The Masten Space
Systems XA-1.0
vertical takeoff rocket has been modeled using VisualCFD 4.1.
VisualCFD
is a "true" three-dimensional axisymmetric and two-dimensional CFD program that solves the inviscid Euler equations
for subsonic, transonic and supersonic flow using automatic mesh generation and
graphical results visualization. VisualCFD provides a
 maximum of
100 cells in
the axial direction, 50 cells in the transverse direction and
10 cells in the circumferential
(3-D) or thickness (2-D) direction. The latest version of VisualCFD has
increased the number of finite-volumes available for analysis from
18,000 cells to 50,000 cells without increasing run time. Due to its "true" 3-dimensional
formulation, VisualCFD provides non-zero lift and non-zero pitching moment for axisymmetric shapes at angle of attack. Model geometry is specified by selecting from a library of standard shapes. Nose sections are defined using one of five basic shapes
that include Conical, Ogive, Elliptical, Parabolic and
Sears-Haack with power series coefficient. The user has the
option for adding up to two constant diameter sections,
one variable diameter transition section and one variable diameter
boat tail section to complete the library of user-defined shapes. For
added flexibility VisualCFD can import up to 1,000 X-R data points
for generating axisymmetric and two-dimensional designs that require
grid clustering in regions where shock waves dominate the flow. Flow
fields are displayed using fill-contour plots, line-contour plots
and surface distribution plots for pressure coefficient, pressure
ratio, temperature ratio, density ratio and Mach number.
See how to easily generate single and
multiple fin sets using VisualCFD.
More ...
Customer Comment: I am a
user of VisualCFD
for our successful Carmack Prize winning 100k' amateur rocket
flight. We used your tool to derive a Cd curve for our airframe that
was clearly superior to other amateur rocketry tools.
Ken Biba, Team AeroPac
SUPERSONIC BLOW-DOWN WIND
TUNNEL
(1" DIAMETER)
 A new
supersonic blow-down wind tunnel is available for testing
aerodynamic shapes. The new 1" inside-diameter supersonic blow-down
wind tunnel, having a test section blockage factor
less than 3%, now joins the successful 1/2"
supersonic wind tunnel.
The AeroRocket 1" diameter supersonic
blow-down wind tunnel performs
drag measurements up to Mach 3.
In addition,
AeroRocket's expertise in the fabrication
of miniature wind tunnel models makes possible the measurement
of supersonic drag coefficient for designs ranging from
simple high power rockets to the very complex HTV-3X and X-30
NASP.
Mach number
verses time is measured during the blow-down process
using a pitot-static pressure probe for measuring total
pressure (Po) and static pressure (Ps) of a compressible
fluid in this case air. Click here
to view a QuickTime movie of a 2.5 second segment
of a typical blow-down wind tunnel test using the 1"
diameter supersonic wind tunnel where nearly
constant Mach 1.6 flow is maintained for approximately
2.5 seconds, an eternity compared to typical shock tube
performance.
 StarShip
VASIMR Analysis:
StarTravel performs
two-body astrodynamics analyses of spacecraft and satellites
knowing burnout velocity and flight-path angle at burnout. For
this purpose StarTravel
uses two-body astrodynamics for determining sub-orbital, orbital and interplanetary motion
around the Earth and Sun. In
addition, StarTravel
performs general heliocentric and Hohmann Transfer orbital analyses.
New in the latest version of StarTravel is the ability
to
determine the ballistic trajectory of rockets
and missiles launched vertically, horizontally and everything in
between. Also,
perform a Variable Specific Impulse Magnetoplasma
Rocket (VASIMR) analysis or a standard constant specific impulse analysis (nuclear propulsion) by specifying starting exhaust velocity and ending
exhaust velocity or constant exhaust velocity for
heliocentric flight to planets and stars.
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