3D Files, Printers, simulations and More
by Robert brand
In the past we used wind tunnels and that was fine for subsonic flights. ThunderStruck does have access to wind tunnels at a number of establishments, but it is unlikely that we will need them. In part because supersonic wind tunnels are rare and because subsonic tests do not translate to supersonic conditions. Why wont we need them? Simply because computer modelling allows us to test most things extremely accurately without the need for wind tunnels. The first part of the equation is to “make” a 3D model of the airframe and from that the options are extraordinary. Simulations of wind tunnels are just one option. What else can you do with the computer files of your model? well, we are not doing everything possible, but here are a few things:
- Produced images of the ThunderStruck craft in solid form (we use Solidworks)
- Rendered the surface to appear metallic
- Added the ThunderStruck Logo and artwork
- Animated the control surfaces on the craft
- Sent it to a TV animator who will use the flight profile to simulate the mission
- Made 3D models of the craft with a 3D printer.
- Made a scaled nose cone for the 1/6th size model for demonstrations. Nose cones are immensely hard to create, but so easy with a 3D printer
- And finally (so far) carried out Mach 2 flight simulations
These simulations show up any problems and thus they have already resulted in small changes to the Phase One craft design. The biggest change will be a longer and more slender nose. You will see why in a moment.
One the right are the original plans from three sides. The software automatically creates the view (top right of image). The 3D files are then produced and it is often that simple. Everything flows from the files. The extension for the files is STL. A printer may break the files up to print an object in two, three or more parts. It depends on the size of object a printer can handle. we wanted a 22cm model of thunderstruck and that was printed in three parts as it was too wide and two high. The parts were simply joined with acetate. It melts the material slightly and the pieces are then welded together without glue.
The solid image looks like this with a little bit of shadow and a plain surface. A “light source” is placed where needed to create essential shadows for the right feel and look.
The image above has been created to appear to sit on a grey surface. Remove that surface and add a metallic texture and a background image and you get this:
The video below shows an animation for the control surfaces. Nothing much to see other than we are working on getting the smaller bits right for the big animations. You can also see our logo on the side so this is a two in one demonstration
Below is a rough picture of the printed 22cm model and the Nose Cone needed for our TV interview on Wednesday with Channel 7 (The Seven Network, Australia). It will be painted. If you look closely you will see the nose cone join and similarly you will see the join on the 3D model.
Below is the plan for the nosecone and it is simple to reproduce. Notice the curved area near the base of the nose cone. This is to ease the airflow over the surface and prevent the delamination of the airflow.
Finally we can do simulations. I will explain what you are looking at below in the next post but wow this stuff is impressive. This si not the top end software, but just a basic system and it is more than adequate for our needs:
Most of the work on this page has been provided by Team Member Ben Hockley of Brisbane. I am grateful that we have a person with his skills in the team.