You are of course correct, but if we're going to point out what's unorthodox, both in the subject and in the analysis and suggestions from vultures' row, we're going to need a bigger server.
Or maybe build a scale model and test the full range of flying characteristics.
You want redneck? Get a few leaf blowers or a fan boat and put er by a smoldering leaf fire.
There is no magic in wind tunnel testing that will provide valid data with someone with little experience or assistance building the models and running the tests. It is easier to spend more time and money in a wind tunnel collecting bad data than by using some of the common mass-market analytical methods. TLAR backed up by sound engineering is often good enough for for airframe design at this level rather than placing absolute trust in tools and methods without the skill or knowledge to identify flaws.
I could be mistaken, but I've always assumed that there's a science behind where the tufts are placed, as opposed to just "hmm, yeah I might stick a few here" - there's also apparently no consideration for the considerably interference a gopro is going to have to the airflow just directly upstream of the intake
Somewhere back in the last 37 pages I had asked if he had done any of this, and someone directed me to his RC plane video. I'm wondering how often do (successful) homebuilt designs get sophisticated testing like that? For some reason I would have assumed most, if not all, do and did (at least for Vans, Velocity, the Lance designs) but maybe not? Presumably though those guys also didn't (and don't) operate in a vacuum either shutting out all outside advice. The VK-30 was pretty unconventional, did Cirrus guys of yonder do windtunnel tests?
I understand, the weight is the big thing. My main point (perhaps poorly illustrated) was that there are other designs out there that stay at one power setting for most of their life that continue to see small design improvements with each update year after year, even if it's just incremental improvements in fuel burn, etc.
Yeah, it's almost like confirmation bias. But a tuft inside the inlet "hmm, yeah, air is going in here!"
Building an RC model of a yet-to-be-built prototype is not 'sophisticated' in and of itself. Models most of us are familiar with would be appropriate for fixed-surface (wing, canard, verticals) sizing and basic geometry and balance at best. Models that would have even a slim chance at identifying the problems people are harping about here are beyond the capability of most average modelers and airplane homebuilder. Configuration-specific controllability characteristics are at least understood well enough to know how to scale a model to represent them, but achieving that scaling is challenging, even moreso as the scale decreases. Predicting handling qualities, aeroelasticity, power/propulsion integration, and cooling issues? Not a chance, at this scale; not from a model, not from a wind tunnel test (in and of itself), and not from X-Plane or any other linear estimation tool.
Why?
True, but but had Peter been part of the KC-135 winglet design I feel like he would have just randomly stuck three or four pieces of yarn on instead of neatly organizing them out like thatWhy?
Here's an image of a KC-135 winglet with tufts. Were they wrong to only tuft the winglet? I mean, if they knew what they were doing shouldn't they have tufted the whole airplane? (facetious question for those not following the thread)
Nauga,
scoped
What you feel he might have done has no bearing on what is actually required. What was the goal of his tuft test and how many did he need for a conclusive answer? There are cases where I can tell what I need to know with a single tuft. You might know it as a yaw string but the principle is the same.
Yeah, 120mph forced through a air-to-water radiator is real ineffective . . . Cooling systems for modernized aircraft engines aren't exactly in the realm of rocket science.
Well, the problem with oil coolers or radiators is that they require airflow to be effective. There's only so much cooling you can do when sitting at idle. Adding an electric radiator fan would be more effective I'd think.
But again, ducting does little of anything for a pusher configuration when not in motion. There's no airflow to go through the ducting, lol. If you've ever dealt with older sports cars like the Corvettes, many of the high-hp models tend to overheat if they sit in traffic at idle. The radiators are small and steeply-angled (to fit in the narrow front end), they don't do well cooling a 427 in 95 degree heat. Once moving, they do just fine.
I’m not sure the fans he used on the test stand were actually installed in the plane.
