DH-1 Dimensions

In preparation for making a CFD model in OpenFOAM, I have put together a drawing showing the main dimensions of the combined stage 1 and stage 2 vehicle. This gives me the data points to create a 2D model.

DH-1 Dimensions

CADAC4 - Head.ASC

The two input files for the ROCKET.EXE executable are the HEAD.ASC and the CADIN.ASC. The HEAD file looks something like this:

 SCROLL NOECHOIN NOINTMSG NOSTGMSG NORANVAR NOTRAJBIN TRAJASC NOSTATBIN NOSTATASC NOTABOUT NOSWEEP
*
      51    REARTH       E Radius of the Earth = 6370987 - m
      52    CRAD         E Conversion factor = 57.29577951 (Deg/Rad)
      54    AGRAV        E Acceleration due to gravity @ sea level             =
      58    WEII3        E Earth Angular rotation = 7.2921154E-5 (rad/s)
     200    MAIR         D =0:Std Atmosphere, =1: Weather Deck
     201    TEMPK        G Atmospheric temperature - degK
     202    PRESS        O Atmospheric pressure - Pa
     203    RHO          O Atmospheric density - kg/m^3
     204    VSOUND       G Sonic speed - m/sec
 *   205    GRAV         O Gravity acceleration - m/s^2
     206    VMACH        O Mach number of rocket - ND
     207    PDYNMC       G Dynamic Pressure - Pa
    1200    MAERO        D =|MAERT|MAERV|, MAERT=1:Type, MAERV:Stage #
 *  1201    CD           O Drag coefficient - ND
 *  1202    CL           O Lift coefficient - ND
    1203    ALPHAX       D Angle of attack - deg
 *  1206    CA           G Axial force coefficient - ND

The original file is generated from the MKHEAD3.EXE program parsing the MODULE.FOR code and extracting all the parameters. However in order to get some output from the run, some of these parameters need to be marked as outputs. This is done by putting an asterisk ('*') in the second column. If there is no asterisk then this variable is not written to the TRAJ.ASC output file.

RL-10 Engine Data

One of the proposed rocket engines used in the DH-1 is the RL-10. To help get some good figures, I have used a summary of data about this engine, along with a few further figures on mass flow rates and the characteristic velocity. These numbers will be used in the simulations to make sure that the thrust and mass flow rates used are correct.

Rocket Engine Data

CADAC4 Software

I have been learning to use the CADAC4 software, which is available for download from the AIAA or as part of the self study CD:

Fundamentals of Six Degrees of Freedom Aerospace Simulation and Analysis in FORTRAN and C++

Library of Flight

2004, CD ROM

ISBN: 9781563476907

The Fortran version of the software is available from the AIAA. However I found there were a few issues when using the code under Windows and compiling with Gnu Fortran (gfortran). To fix this I had to edit some of the files especially to do with reading and opening files. I will upload the corrected versions of these files here.

Reference link: http://arc.aiaa.org/doi/book/10.2514/4.102523
 

 

DH-1 Detail Data

DH-1 Detail Data

I have put together some summaries of all the relevant figures for the DH-1 vehicle as per the data in the book. In the version I have the are some inconsistencies with the figures used so this puts it all together to make it clear.

DH-1 Detail Data