Tuesday 29 May 2012

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

Wednesday 23 May 2012

CADAC Variable Locations

In the Fortran code for the CADAC4 software, variables are defined with a specific location. The number range is in the manual, however which variables are stored in which number location is not summarised. To help with this I wrote a Perl script to scan all the Fortran user modules and put together a list of all the names and locations. This helps me to know which spots are free for adding my own code, and means that if I do use a parameter it will have the same location.

CADAC4 Variable Locations

Updated Rocket Engine Data

I have been working on updating my summary of Rocket Engine Data. I have added in the Russian RD-192 engine, as it is about the right size for the main boost engine for the DH-1. I have been trying to find as much data on this as I can, because it runs on the Methane/LOX mixture which is of interest for the first stage.

I am also working on trying to get the OpenFOAM CFD software installed to try and get some basic numbers for the drag coefficients. At the moment the CADAC software is using the same coefficients from the basic sounding rocket example. Also the thrust calculation is a bit wrong because it assumes the exit pressure of the rocket will be the atmospheric pressure (Pe = Patm). However this is not the case especially for the sustainer RL-10A-4 engines.