patrick_g
Elite Member
Regarding the bowline... Besides there being both a cowboy bowline and a sailor bowline (AKA innie and outie) there are several variants of bowlines like the tugboat bowline, anchor bowline etc.
The reason (excuse) for my bowline example was to OPEN SOME MINDS to possibilities beyond ones own self inflicted myopia. This holds for the classroom example as well as the will it fly thing.
You may note that some of us are still doggedly (and relatively mindlessly) holding onto one position or the other, clutching to their hearts, assumptions (not necessarily stated in the problem but just plucked from somewhere) and think those of opposite persuasion are daft at best.
Guys, get over it, depending on assumptions and definitions, EITHER can be right OR wrong. Until and unless all the definitions and assumptions are teased out and agreed upon, arguing at cross purposes just wastes time.
Once you accept the MAGIC CONVEYOR the plane is doomed by the laws of physics to never take off. So long as you conveniently restate the problem in your own terms to nullify the magic conveyor (voiding the contract so to speak) you can easily make the plane take off.
This was a thought experiment not a trial such as performed by the Myth Busters whose truck pulling the "conveyor" was NOT equivalent to a MAGIC CONVEYOR. A comparison of apples to light bulbs. The one has NO BEARING on the other.
There currently exists no technology to even get close to building an actual real conveyor that will interfere with the take off of an airplane capable of taking off with no conveyor involved. So, for any realists with limited imagination and limited visualization ability who can't wrap their minds around the concept of the "MAGIC CONVEYOR", clearly the plane will always take off. For the rest of us who can grasp the concept of the "MAGIC CONVEYOR" we can see that the plane could theoretically be prohibited from taking off. This second position has absolutely nothing to do with reality and is just the result of applying simple physics to a theoretical situation to determine what would happen IF a "MAGIC CONVEYOR" could be built.
Now, as regards the helo on the turntable. If the turn table rotates at the same speed as the rotor but in opposite direction then the blade is standing still in the air mass and the relative wind over the blades is zero and so there is zero lift. Collective and cyclic pitch are not effective in the least when there is no airflow over the airfoil.
The model with the little engine mounted to the rotor has been around for decades and decades in one form or another. I have even flown a freeflight lampshade with a model airplane engine mounted vertically. You need fins inside the "duct" to cancel torque induced rotation or centrifugal force can increase to the point of disturbing fuel flow.
Pat
The reason (excuse) for my bowline example was to OPEN SOME MINDS to possibilities beyond ones own self inflicted myopia. This holds for the classroom example as well as the will it fly thing.
You may note that some of us are still doggedly (and relatively mindlessly) holding onto one position or the other, clutching to their hearts, assumptions (not necessarily stated in the problem but just plucked from somewhere) and think those of opposite persuasion are daft at best.
Guys, get over it, depending on assumptions and definitions, EITHER can be right OR wrong. Until and unless all the definitions and assumptions are teased out and agreed upon, arguing at cross purposes just wastes time.
Once you accept the MAGIC CONVEYOR the plane is doomed by the laws of physics to never take off. So long as you conveniently restate the problem in your own terms to nullify the magic conveyor (voiding the contract so to speak) you can easily make the plane take off.
This was a thought experiment not a trial such as performed by the Myth Busters whose truck pulling the "conveyor" was NOT equivalent to a MAGIC CONVEYOR. A comparison of apples to light bulbs. The one has NO BEARING on the other.
There currently exists no technology to even get close to building an actual real conveyor that will interfere with the take off of an airplane capable of taking off with no conveyor involved. So, for any realists with limited imagination and limited visualization ability who can't wrap their minds around the concept of the "MAGIC CONVEYOR", clearly the plane will always take off. For the rest of us who can grasp the concept of the "MAGIC CONVEYOR" we can see that the plane could theoretically be prohibited from taking off. This second position has absolutely nothing to do with reality and is just the result of applying simple physics to a theoretical situation to determine what would happen IF a "MAGIC CONVEYOR" could be built.
Now, as regards the helo on the turntable. If the turn table rotates at the same speed as the rotor but in opposite direction then the blade is standing still in the air mass and the relative wind over the blades is zero and so there is zero lift. Collective and cyclic pitch are not effective in the least when there is no airflow over the airfoil.
The model with the little engine mounted to the rotor has been around for decades and decades in one form or another. I have even flown a freeflight lampshade with a model airplane engine mounted vertically. You need fins inside the "duct" to cancel torque induced rotation or centrifugal force can increase to the point of disturbing fuel flow.
Pat