My Boomerang Won’t Come Back
I thought I’d work on some props today, to do this I targeted a plane which I have good data for but one which had a troublesome prop in the past, the CAC Boomerang. Yes I know, what Boomerang you say, well I have had a working FM for, oh, about 3 years now, every now and again I dust it off and improve it. Currently I fly it using the F4F 3D but one day I hope someone will build a correct 3D to match, I live in hope.
Anyway, I chatted with GH again today over the prop solidity and how this effects speeds. I discovered that the highter if you fix solidity, less speed range you have available before the prop engine will over rev. ie. whilst 20 deg prop pitch was enough at solidity of 0.065, when I increased the solidity to 0.095 I found I had narrowed my available engine speed operational range. So now the Boomer was more prone to over revving in a dive, which may be more correct, or not? I did some reading and some tweaking, I set the HP of the Boomer, rebuilt the wings to new ideals, trimmed the weight distribution and worked the prop over. I got a good speed curve, after a lot of debugging, that seems to allow correct solidity figures of 0.095 (% of disk area) and much more realistic drag and mach figure used for the prop of ~0.8.
I now await the 3D knight in shining armor to ride in and build a matching airframe. In the mean time I’ll expand these new props over more aircraft and hopefully I will see the same kinds of positive outcomes.
Um…hang tight. It appears that Boomerang might somehow “come into being” after all.