Shameless update from Dale Kramer

On Saturday, March 19, 2016 at 4:50:48 PM UTC-7, DaleKramer wrote:
On Saturday, March 19, 2016 at 6:04:23 PM UTC-4, 2G wrote:
On Saturday, March 19, 2016 at 11:21:45 AM UTC-7, DaleKramer wrote:
I believe I have answered every question.

There is NO reason to compare my design to a helicopter in terms of disc loading since it does not operate like one.

I suggest to you that you read up on multirotor design and control.

I believe that this revolution of flight, over the last decade, has resulted in more multirotor controlled air vehicles flying than all other air vehicles combined.

Yes, perhaps I should mention a little more about that in the link.

I didn't say that you didn't answer the questions; it was your attitude towards me that I called you on.

Your "design" is not a revolution, just a variation on a concept that has been tried in the past and rejected by every aviation company since.

Further review caused me pause; the pilot, along with all controls and instruments, must rotate in two dimensions AND open the cockpit to the full prop down wash during the most critical phases of flight: takeoff and landing. Is this so?

Attitude goes both ways.

I has also been said that no designs are revolutions, just variations.

In hover flight the pilots seat only ever opens a maximum of 90 degrees, the final 20 degrees is when engines are shut down. At 90 degrees, the pilots upper torso is still in the fuselage, the pilots legs from the waist down are enclosed in a secondary shell (with airbags). Airflow should be no worse than an open cockpit aircraft or a motorcycle. This is a 'sport' design and I don't expect it to appeal to the non-sporting. The pilots seat could be fully enclosed and still rotate, but I choose not to do that initially.

The controls are fly by wire so there is very little complexity in that 110 degree travel joint.

Your images show the legs forward in level flight, and the legs 90 degrees out of the plane in the opposite direction. I fail to see how this can be done with a rotation about just one axis. In any event, this requires a major body motion at a critical moment. Have you ever heard of "vertigo" and what causes it? This can be caused by just tilting the head down. Apparently you are completely unaware of this.

2G there is a lot of "stinking attitude" as you say here, but I am afraid its coming from you Thats not an unusual thing for this web site lol. I dont know much about mr kramer but I do know that he has not only sucessfully designed aircraft but also sold them to other folks who enjoy them. Will this project work? Who knows, there are definitely huge tecnological challenges here, and this guy is going to need help from other specialized engineers. That being said, your attitude is the type which I am sure the wright bros encountered all day long, namely folks who have'nt done squat themselves but sure can point out all the faults in another persons aspirations. Surely Dale knows this is not the forum to use for gaining serious investment capital, or for that matter "intelligent" aerodynamic advice. He appears to just be getting his ideas out into the public "air" a bit. So dude, lighten up, and at least applaude the guy for thinking outside the box.

On Sunday, March 20, 2016 at 7:26:55 AM UTC-4, wrote:
Surely Dale knows this is not the forum to use for gaining serious investment capital, or for that matter "intelligent" aerodynamic advice.

That is for sure! Exactly zero of the backers so far have been from my soaring acquaintances.

So I am still here because it is somewhat enjoyable and stimulating to share these ideas now.

On Sunday, March 20, 2016 at 8:33:24 AM UTC-7, DaleKramer wrote:
On Sunday, March 20, 2016 at 7:26:55 AM UTC-4, wrote:
Surely Dale knows this is not the forum to use for gaining serious investment capital, or for that matter "intelligent" aerodynamic advice.

That is for sure! Exactly zero of the backers so far have been from my soaring acquaintances.


+1, but I want a delivery position...if it works. Fingers crossed.

Andy

On Sunday, March 20, 2016 at 3:08:51 PM UTC-4, Andy Blackburn wrote:
On Sunday, March 20, 2016 at 8:33:24 AM UTC-7, DaleKramer wrote:
On Sunday, March 20, 2016 at 7:26:55 AM UTC-4, wrote:
Surely Dale knows this is not the forum to use for gaining serious investment capital, or for that matter "intelligent" aerodynamic advice.

That is for sure! Exactly zero of the backers so far have been from my soaring acquaintances.


+1, but I want a delivery position...if it works. Fingers crossed.

Andy


Wow, thanks!

On Sunday, March 20, 2016 at 3:08:51 PM UTC-4, Andy Blackburn wrote:
+1, but I want a delivery position...if it works. Fingers crossed.

Andy

I will consider that a deposit on delivery position #1

On Sunday, March 20, 2016 at 2:22:53 PM UTC-7, DaleKramer wrote:
On Sunday, March 20, 2016 at 3:08:51 PM UTC-4, Andy Blackburn wrote:
+1, but I want a delivery position...if it works. Fingers crossed.

Andy

I will consider that a deposit on delivery position #1

#1? maybe I need a few brave should in front of me.

Yes - way back when I worked at NASA Ames on variable stability helicopters as part of grad school. They had the XV-15 tilt rotor there and well as the RSRA - talk about bad transitions to forward flight. It has a rotor that was an oval cross section with blowing slots on both leading and trailing edges. The idea was to stop the rotor in flight and swap the slots you were blowing out of on the blades that were facing aft (they were symmetric airfoils (fore and aft AND top/bottom) - so "aft" was more of a term of art as it depended entirely on the blowing setup. In forward flight it was an X-wing planform. I understand the transitions were "exciting".

You have an easy problem in comparison.

I agree with enough power and pitch authority you ought to be able to make the transition to forward flight (and back) without to much drama. The question I can't answer with simple math is exactly how much power you need. You've got a swept wing so it ought to be able to produce lift at pretty high AOA which is good. At some point the vertical component of the thrust vector will be insufficient to hold the aircraft in hover and as you continue to pitch over the wing better take up the slack or you will be in ballistic territory. If your total thrust to weight is 1.3:1 you will run out of thrust to hold hover at T*sin(Theta) = W, or Theta = arcsin(1/1.3) = arcsin(0.77) = 50.3 degrees nose up pitch. That might be a bit high, even for a highly swept wing. You'll need to get the elevator unstalled as well if you want to actually fly the thing through the transition with the stick. The hope is that the nose will want to pitch over anyway once you get started so you'd think you could sort of mush your way through the transition until the boundariy layer on the wing gets attached and the wing gets lifting - and hope that it doesn't get so draggy that it wants to mush and settle for very long.

My Dad was the project test pilot for a variation on this theme back in 1958:

https://www.youtube.com/watch?v=wDstVGAmI74

Like I said, with enough thrust you can do pretty much anything you want.

Andy

Andy, give up now on the hovercraft and RC drones, just launch one of those F-100D ZEL from you back yard.

On Sunday, March 20, 2016 at 4:30:23 PM UTC-7, Andy Blackburn wrote:
On Sunday, March 20, 2016 at 2:22:53 PM UTC-7, DaleKramer wrote:
On Sunday, March 20, 2016 at 3:08:51 PM UTC-4, Andy Blackburn wrote:
+1, but I want a delivery position...if it works. Fingers crossed.

Andy

I will consider that a deposit on delivery position #1

#1? maybe I need a few brave should in front of me.

Yes - way back when I worked at NASA Ames on variable stability helicopters as part of grad school. They had the XV-15 tilt rotor there and well as the RSRA - talk about bad transitions to forward flight. It has a rotor that was an oval cross section with blowing slots on both leading and trailing edges. The idea was to stop the rotor in flight and swap the slots you were blowing out of on the blades that were facing aft (they were symmetric airfoils (fore and aft AND top/bottom) - so "aft" was more of a term of art as it depended entirely on the blowing setup. In forward flight it was an X-wing planform. I understand the transitions were "exciting".

You have an easy problem in comparison.

I agree with enough power and pitch authority you ought to be able to make the transition to forward flight (and back) without to much drama. The question I can't answer with simple math is exactly how much power you need. You've got a swept wing so it ought to be able to produce lift at pretty high AOA which is good. At some point the vertical component of the thrust vector will be insufficient to hold the aircraft in hover and as you continue to pitch over the wing better take up the slack or you will be in ballistic territory. If your total thrust to weight is 1.3:1 you will run out of thrust to hold hover at T*sin(Theta) = W, or Theta = arcsin(1/1.3) = arcsin(0.77) = 50.3 degrees nose up pitch. That might be a bit high, even for a highly swept wing. You'll need to get the elevator unstalled as well if you want to actually fly the thing through the transition with the stick. The hope is that the nose will want to pitch over anyway once you get started so you'd think you could sort of mush your way through the transition until the boundariy layer on the wing gets attached and the wing gets lifting - and hope that it doesn't get so draggy that it wants to mush and settle for very long.

My Dad was the project test pilot for a variation on this theme back in 1958:

https://www.youtube.com/watch?v=wDstVGAmI74

Like I said, with enough thrust you can do pretty much anything you want.

Andy

Andy,

Sounds like the RSRA had a reaction rotor powered by air, but I don't see that in the specs I found? And are you saying that after the RSRA rotor was stopped, they continued to blow out the 'horizontal flight' trailing edges for some reason?

I was assuming that there may be some loss of altitude during the vLazair 'push' to forward flight. Part of the 'push' transition procedure could not only be 'only push when you get to a certain vertical speed' but also a minimum height above ground to make allowance for a slight height loss. Or worst case it might be 'climb straight to X altitude and then push over, it will dive some but you'll pull out of it In the early 3D flight RC model days I had a model with not much over 1/1 thrust. I have never been able to hover very long but I don't remember ever having much altitude loss or control problems coming out of a hover attempt. I know Mr Reynolds and a lot of other things likely skew that example but I can't wait to see what my 1/4 scale will do on these transitions (btw I am planning a tether system for 1/4 scale testing).

Fortunately I believe the stability through transitions will be augmented by the multirotor controller which is closed loop on heading and pitch until the throttle command is shut down to it when horizontal flight is achieved..

I also think it is possible that the aerodynamic controls are not needed at all below their un-stalled AOAs.

Wow, that video clip is awesome! I think of my electrics on the vLazair as a sort of re-chargable JATO system