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HyperCFD™
3.5
Supersonic
and Hypersonic Re-Entry Vehicle and Rocket Analysis using 3-D Gasdynamics
Determine drag coefficient
(Cd), center of pressure (Xcp), CN-alpha and Cm-alpha of supersonic
and hypersonic rockets and re-entry vehicles. In addition, on
a separate screen HyperCFD displays and plots CN-Body, CN-Fins,
CN-Total and Cm-Total as a function of angle of attack (AOA)
using up/down controls. HyperCFD uses empirical aerodynamic corrections to
the modified Newtonian surface inclination method that allows
excellent results from Mach 1.05 to Mach 20. Includes a wide
variety of nose cone shapes and fin cross-sections. Nose cone
shapes include, conical, elliptical, parabolic, power series
Sears-Haack, tangent ogive and spherical segment. Fin cross-sections
include single wedge, symmetrical double wedge, arbitrary double
wedge, biconvex section, streamline section, round-nose section,
and elliptical section fin shapes. HyperCFD is useful to
determine supersonic and hypersonic rocket drag and center of
pressure location for medium and large scale professional
sounding rockets.
New in this description is a methodology to determine
thermal loads into the airframes of
supersonic and hypersonic rockets using temperature distribution
(T/Tinf) results from HyperCFD and
AeroCFD.
In addition, a Microsoft
Excel thermal analysis
(50 KB) spreadsheet is available as a free
download.
Also new in
this description is a slender missile
analysis that validates HyperCFD
for the prediction of drag coefficient (Cd) and center of pressure
location (XCp) for the flight regime which extends from Mach 1.05 to
Mach 6.
The following links clearly illustrate
how HyperCFD has been used to analyze re-entry vehicles.
Revisiting China’s Early Warhead Designs
Iranian Warhead Evolution
Standard
HyperCFD Features
1) Temperature on the surface of the rocket relative to free-stream
conditions.
2) Pressure and temperature can be output to a CSV format file and read
as a text file or Excel spreadsheet.
3) Cd estimation as a function of AOA based on the Lester Lees
modified Newtonian surface
inclination theory.
4) Cd estimation and XCp estimation as a function of small angle
of attack (1 to 2 degrees).
5) Cd estimation for decreasing cross-sectional components.
6) Display fin normal force coefficient (CN Fins), body normal
force coefficient (CN Body), total normal force coefficient (CN
Total) and total moment coefficient (CM Total) in addition to
standard drag coefficients and center of pressure location in
CSV format.
7) Plot shock wave shape and generate shock wave coordinates for
sharp nose and blunt body projectiles.
8) Plot aerodynamic coefficients verses Mach number for Cd
(subsonic, supersonic and hypersonic), XCp/L (Center of pressure
location), CN (Normal force coefficient) and CM (Moment
coefficient).
9) HyperCFD computes subsonic nose-body friction drag coefficient,
nose-body base drag coefficient, fin surface drag coefficient,
fin interference drag coefficient for laminar and turbulent flow
based on NASA high speed wind tunnel data.
The following shock wave values are displayed in the Rocket
Geometry plot section
10a) Nose tip half-angle for attached shock or body half-angle
after blunt nose for detached shock.
10b) Shock wave half-angle for
attached (pointed nose) and detached (blunt nose) shock waves.
10c) Shock x-location from nose tip (Shock-x).
HyperCFD Results
Case #1: Re-Entry Vehicle
HyperCFD main screen displaying
re-entry vehicle
HyperCFD re-entry vehicle pressure
distribution
Case #2: Conical Nose Cone
Case #3: Missile With Fins
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This
section discusses the aerodynamic predictions, tests and
analyses of a slender fin stabilized missile
configuration for Mach numbers that range from 1.05 to
6. Prediction techniques consisted of both empirical and
analytical methods, including a state-of-the-art
computational fluid dynamics (CFD) code. Free flight
tests in the USAF Aeroballistics Research Facility were
conducted on sub-scale wind tunnel models to obtain an
aerodynamic baseline to which the CFD predictions could
be compared. This section summarizes these results and
validates HyperCFD for the prediction of drag
coefficient (Cd) and center of pressure location (Xcp)
for the flight regime, which extends from Mach 1.05 to
Mach 6.
This section summarizes the results from the paper,
Aerodynamic Test and Analysis of a Slender Generic Missile
Configuration published by the AIAA Atmospheric Flight
Mechanics Journal in 1989 and authored by John Cipolla. |
Hypersonic missile In free flight
as tested in the ARF
HyperCFD main screen displaying
hypervelocity missile
Aerodynamic coefficients plotted
using Cd vs Mn command button
HyperCFD fin geometry screen for
hypervelocity missile
HyperCFD aerodynamic coefficients
as a function of AOA on body, fins and fin-body
HyperCFD Motor On/Off screen
Free Flight data measured using the
USAF Aeroballistic Research Facility (ARF)
Free-flight center of pressure
location and
drag coefficient of a slender missile with fins compared to HyperCFD.
Free
Flight data from "Aerodynamic Test and Analysis of a Slender Generic Missile
Configuration"; John Cipolla, AIAA.
Case #4: Biconic Re-Entry Vehicle
HyperCFD analysis of a Biconic re-entry
vehicle operating at Mach 5 to determine Cd (drag coefficient),
Xcp (center of pressure) and CNa (lift slope)
Case #5: LGM-30 Re-Entry Vehicle
LGM-30
Minuteman re-entry vehicle during post-boost flight
LGM-30
Minuteman HyperCFD analysis for Mach 25 flight. Dimensions
estimated from images.
Case #5: Mars Phoenix Entry Capsule
AeroCFD used to generate a 3-D composite view
of the Mars Phoenix entry capsule.
HyperCFD analysis of the Mars
Phoenix entry capsule operating at Mach 18.5 to determine Cd,
Xcp and CNa
Wall Temperature, Recovery
Temperature and Airframe Thermal Loads
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This is a
simplified discussion of the interaction between
vehicle aerodynamics and heat loads on the airframe of a
supersonic or hypersonic vehicle. First, the heating
rate per area, q (W/m2) is defined as,
q = k (Tr - Tw) where k is the
convective heat transfer coefficient (W/m-K), Tr is the recovery or stagnation
temperature, Tw is the wall temperature and r
is the recovery factor which is equal to 1 for this
example. Both temperatures are defined in degrees Kelvin
(K). Wall temperature is computed using HyperCFD or
AeroCFD and is derived from the ratio of T/Tinf where Tinf
is the local atmospheric temperature and T is the wall
temperature (Tw). The example below (second image) determines wall
temperature, recovery temperature and maximum heat load
into the airframe near the nose tip of a supersonic or
hypersonic rocket. For this example Prandtl number (Pr)
and recovery factor (r) both equal 1 and k = 151 W/m-K. |
HyperCFD analysis of a
hypersonic missile to determine airframe temperature
distribution (T/Tinf)
DETERMINE WALL TEMPERATURE AND
THERMAL LOAD
For a complete analysis download
the free thermal analysis (50 KB)
Example to determine wall
temperature, recovery temperature and airframe heat rate of a
hypersonic rocket
SYSTEM REQUIREMENTS
(1) System: Windows 98, XP, Windows 7, 8, Windows 10 (32 bit and 64 bit), NT or Mac with emulation
(2)
English (United States) Language
(3)
256 colors
PROGRAM REVISIONS
HyperCFD
3.5.0.1
(December 20,
2016)
1)
Greatly enhanced computational speed for Windows 8,
10 and other enhancements. Verified compatibility with Windows 10.
2) Plot shock wave shape and generate shock wave coordinates for
sharp nose and blunt body projectiles.
3) Plot aerodynamic coefficients verses Mach number for Cd
(subsonic, supersonic and hypersonic), XCp/L (Center of pressure
location), CN (Normal force coefficient) and CM (Moment
coefficient).
4) HyperCFD computes subsonic nose-body friction drag coefficient,
nose-body base drag coefficient, fin surface drag coefficient,
fin interference drag coefficient for laminar and turbulent flow
based on NASA high speed wind tunnel data.
The following shock wave values are displayed in the Rocket
Geometry plot section
5a) Nose tip half-angle for attached shock or body half-angle
after blunt nose for detached shock.
5b) Shock wave angle for a
pointed nose OR shock wave angle of an equivalent pointed nose
using blunt nose-body angle.
5c) Shock x-location from nose tip (Shock-x).
HyperCFD
3.5.0.2 and 3.5.0.3
(December 30, 2016)
1) Refined results of the shock wave shape analysis and
fixed a few run time errors.
HyperCFD
3.5.0.4
(January 3, 2017)
1) Added background theory of attached shock
waves and detached shock waves In the HyperCFD Instructions
section.
HyperCFD
10.0.0.1
(December 20, 2021)
1) Added the capability
to generate and model 3-Dimensional airframe geometry.
2) HyperCFD 10.0 models hypersonic glide vehicle (HGV)
aerodynamics.
HyperCFD
10.0.0.2
(November 16, 2022)
1) Corrected wave drag
under prediction for Airframe Geometry screen. |
