Originally Posted by dave1993

regarding the airfoil, is it possible you have not seen a single one of the photos ive put up here and scattered just about everywhere else on rcgroups? like just a few posts back for example?

Many old guys call those Trainer airfoils. When you get your big boy pants you can start using airfoils that don't have a ton of drag if you try to go fast.

Originally Posted by aeronaut999

Yes I'm aware that by the aerodynamicist's system of specifying airfoils by the shape of the camber line and the variation of thickness along the camber line, it's an arbitrary or accidental distinction as to whether the undersurface happens to have any undercamber or not.
Steve

That's what I was about to say! Thanks for the background, I'm not very familiar with hang gliders.

Originally Posted by Steve Anderson

Many old guys call those Trainer airfoils. When you get your big boy pants you can start using airfoils that don't have a ton of drag if you try to go fast.

sorry gramps. if getting "big boy pants" means spending a grand a month on the hobby and needing to join ama for fields big enough to fly that fast, ill pass.

for last few years ive been happy to experiment with wings and power systems and float around nearby soccer fields with my deltas and 4' foamies. no inclination to grow up and end up like some of the guys i see who dont seem to be having any fun at all. just bragging about how much they spent and recollecting "good old days". nope, not for me.

"Big boy pants"-- made me laugh. Time to let this thread simmer for a few more days, see ya in a while. Steve

Originally Posted by dave1993

sorry gramps. if getting "big boy pants" means spending a grand a month on the hobby and needing to join ama for fields big enough to fly that fast, ill pass.

for last few years ive been happy to experiment with wings and power systems and float around nearby soccer fields with my deltas and 4' foamies. no inclination to grow up and end up like some of the guys i see who dont seem to be having any fun at all. just bragging about how much they spent and recollecting "good old days". nope, not for me.

No that’s not what it means. A little time figuring out why you owe Don Stackhouse an apology and the reason you need to insult people who disagree with you may help you figure what it means.

Originally Posted by dave1993

maybe its just me but im less impressed by aerodynamic theory than real world obesrvations.

Maybe this thread ought to just park until Dave shares those real-world observations he is always talking about-- don't know why he won't share those pressure readings from the top/ bottom of the wing of his park flyer that show how the high pressure on the bottom surface is the dominant effect contributing to the lift force on the airfoil? Not that that has anything to do with whether lift involves a downwash (which it does), but still, it seems to be one of his favorite topics, so why won't he share the evidence with us? Maybe-- it's because that would belong in the "modelling science" forum? Which this is not...

This is the "bash academic theory" / "extol the virtues of my favorite branch of RC flying and bash the rest" / "make generalized physic arguments about lift based on quirky things I think I'm seeing in slow flying aircraft" / "misrepresent my opponent's statements/ predictions" / "engage in illogical arguments" / "argue against the existence of logic" / "accuse everyone else of being a religious nut case" forum.

You mentioned playing with cooling fans in your last post.

We all know that a propeller makes a strong propwash behind, but not in front of, the propeller disk, in terms of the velocity of the flow at any given point. (I.e. the outflow is much more concentrated than the inflow.)

So, is this yet another manifestation of the idea that an airfoil has a stronger high-pressure area on the bottom and only a weaker low-pressure area on top? If the low pressure on top were stronger than the high pressure on the bottom, then the "sucking" propwash in front of the prop would be stronger than the "blowing" propwash behind the prop? Even if the prop is operating at a very high airspeed and is using an airfoil whose pressure distribution is well known to be the opposite (low-pressure on top of the airfoil is stronger than high-pressure on bottom)? That would pretty much be the logical extension of the positions you've taken over the last few days.

Real world this, real world that, we would be all ears if you would tell us something from the real world that pertained in any real way to what we've been talking about. Rather than saying "you'd get all this if you knew about thin films, so go google thin films".

This thread is long overdue for being put out to pasture...

On the other hand maybe it ought to remain as a special preserve for this kind of twisted discussion-- sort an exhibit, a museum, a zoo?

Steve

Originally Posted by Steve Anderson

No that’s not what it means. A little time figuring out why you owe Don Stackhouse an apology

your post dont sound like trying to elicit an apology. unless you consider don an airfoil type:

Originally Posted by Steve Anderson

When you get your big boy pants you can start using airfoils that don't have a ton of drag if you try to go fast.

if you read those original posts and my reply youll see i was strictly referring to ultralights and you and dons infatuation with speed dont apply there. if necessary i can go into more detail on legal issue involving speed limits of part 103.

i agree there was a considerable amount of "twisting" going on and an apology might be due. but not to the person you suggest. try reading those posts and links again. i suspect that in view of what appear to be romantic involvements this might not happen.

Originally Posted by aeronaut999

Not that that has anything to do with whether lift involves a downwash (which it does), but still, it seems to be one of his favorite topics, so why won't he share the evidence with us? Maybe-- it's because that would belong in the "modelling science" forum? Which this is not...

well... since op and anyone else sharing his viewpoint were simply run out of town then it must be open season topic wise. in any case understandable why those who dont read and/or understand posts might think they are ot.

Originally Posted by aeronaut999

This is the "bash academic theory" / "extol the virtues of my favorite branch of RC flying and bash the rest" / "make generalized physic arguments about lift based on quirky things I think I'm seeing in slow flying aircraft" / "misrepresent my opponent's statements/ predictions" / "engage in illogical arguments" / "argue against the existence of logic" / "accuse everyone else of being a religious nut case" forum.

lol! cant argue with that. pretty obvious a few guys here do NOT like it when their pet theories are challenged.

Originally Posted by aeronaut999

You mentioned playing with cooling fans in your last post. We all know that a propeller makes a strong propwash behind, but not in front of, the propeller disk. So, is this yet another manifestation of the idea that an airfoil has a stronger high-pressure area on the bottom and only a weaker low-pressure area on top?

its not so much that one is stronger than the other but as i said before:

"mostly im not convinced low pressure above is as effective as air from below."

at least in term of lift. i repeat this for any interested parties who actually do read the posts here.

Originally Posted by aeronaut999

Real world this, real world that, we would be all ears if you would tell us something from the real world that pertained in any real way to what we've been talking about.

how many actual experiments have you conducted and posted since the start of this thread. you know, ones with photos and description of results. in fact going though your post history not many since joining this forum. let me count... well.. there must have been at least ONE. no?

going through a persons forum history can be very telling. browsing list of attachments in their blog too. imo some guys here would be much happier in ltup where most have never even seen an rc model let alone built or flown one.

Originally Posted by aeronaut999

Rather than saying "you'd get all this if you knew about thin films, so go google thin films".

thin film technology is fasicnating and i have played with vacuum deposition at the school but i dont recall ever bringing that up here. maybe you confuse it with my response to dpates query about single surface wings. my description of os film was quite appropriate if somewhat unappreciated. maybe more so for those with actual sense of humor too.

Originally Posted by aeronaut999

This thread is long overdue for being put out to pasture... On the other hand maybe it ought to remain as a special preserve for this kind of twisted discussion-- sort an exhibit, a museum, a zoo?

lol! like i said...

Originally Posted by dave1993

your post dont sound like trying to elicit an apology.

An apology is not what I was trying to elicit with that comment, you are correct.

Originally Posted by dave1993

unless you consider don an airfoil type:

I think Don is a human, not an airfoil.

Originally Posted by dave1993

if you read those original posts and my reply youll see i was strictly referring to ultralights and you and dons infatuation with speed dont apply there. if necessary i can go into more detail on legal issue involving speed limits of part 103.

i agree there was a considerable amount of "twisting" going on and an apology might be due. but not to the person you suggest. try reading those posts and links again. i suspect that in view of what appear to be romantic involvements this might not happen.

I read some of your interaction with Don and also what you have written here. I don't need to re-read it.

You really like throwing out accusations about people. You also like to have everyone go back and do this and that, but when you're called out on something you said, you don't do any work. How is that list of Newtonian deniers coming?

Originally Posted by dave1993

i suspect that in view of what appear to be romantic involvements this might not happen.

Why would you suspect that? Are you and Tim having one?