This Instructable is as an add-on to my prior instructable, except this time I am using a K14/6087 turbo found on all 1980's and early 1990's volkwagen turbo diesels.. It has an Inducer diameter of 30.15mm. Any turbocharger will work, but larger turbos off older petrol cars are better suited. This K14 will serve as a test bed for some experimental designs of mine, over time.
Step 1: Jetspecs.exe
Choose your turbo. Alternatively, use any turbo you can get! Then the calculations. The program you use to calculate critical dimensions is called jetspecs.exe and its widely available for download across the web. For a 30.15mm inducer, with 8mm primary holes, 10mm secondary's and 12mm tertiary's see the image attached. The highlighted parts are the important bits, the arrows indicate a required input. You could use any size holes, but you want larger rather than smaller holes so the air stream penetrates the flame column well.
Step 2: Choose Your Combustion Chamber!
Attached are a few pics of various combustor variations that I experimented with, I always find myself returning to the 'can' type. Notice in the 3rd pic the section view, there is a part highlighted green. These are 'locator' rings welded to the top and bottom plates on the combustor. The flame tube then is made shorter (180mm f.t. vs 200mm combustor) this is to allow for thermal expansion as the f.t. heats up. Without this you will be putting the combustor under unnecessary thermal and mechanical stress!!
Step 3: Experiment...
... and share what you did! What worked for you, what didn't work for you. The rest of us might benefit from it :)