F.A.O.: Gabriel, The Hell Better Aeroengineer

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3WE
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F.A.O.: Gabriel, The Hell Better Aeroengineer

Postby 3WE » Tue Nov 13, 2018 2:41 pm

https://www.youtube.com/watch?v=OacVy8_ ... io=1#t=299

Just before 2:30 on this movie, they focus on a rocket engine from a Total Air Disaster (which I believe is an unmanned test) and follow it for a couple minutes.

I have always been impressed at how this engine is in some sort of aerodynamically stable, non-tumbling state. Rock solid in pitch (no phugoids), Rock solid in roll, AND a nice stable yaw motion.

AND, even though I am a fertilizer chucker, I try to envision what surfaces and airflows are driving this behaviour...is that ragged "fuel line" hanging off the back acting as a 'rudder' on this thing?

Do you have any thoughts on this?
Commercial Pilot, Vandelay Industries, Inc., Plant Nutrient Division.

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Gabriel
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Re: F.A.O.: Gabriel, The Hell Better Aeroengineer

Postby Gabriel » Wed Nov 14, 2018 5:48 am

No, sorry.

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Re: F.A.O.: Gabriel, The Hell Better Aeroengineer

Postby 3WE » Thu Nov 15, 2018 9:32 pm

No, sorry.
Not even impressed with that seemingly stable fall?
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Re: F.A.O.: Gabriel, The Hell Better Aeroengineer

Postby ocelot » Fri Nov 16, 2018 3:59 am

It is tumbling, just in slow motion. That the axis of the tumble is close to vertical is a coincidence. (Or maybe not, it probably appealed to the director so we see this part and not others.)

If you spin an object on two different axes, this ends up being equivalent to a single resultant spin on some other axis; it's a simple vector addition.

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Re: F.A.O.: Ocelot, The Hell Better Aeroengineer

Postby 3WE » Fri Nov 16, 2018 4:53 pm

It is tumbling, just in slow motion. That the axis of the tumble is close to vertical is a coincidence. (Or maybe not, it probably appealed to the director so we see this part and not others.)

If you spin an object on two different axes, this ends up being equivalent to a single resultant spin on some other axis; it's a simple vector addition.
1. Ok, you have engaged geospatial and mathematical thought processes...most interesting and I think I understand and valid comments!

2. I think I still disconcur. This thing is in "stable flight*", and has something making it turn.

*Yeah, it's a stretch to say "stable flight" but it's a VERY SMALL stretch. You have this continuum of a glider, a "typical" airplane, the space shuttle, this engine and then a rock with just the right shape to establish an aerodynamically stable fall...

Thanks.
Commercial Pilot, Vandelay Industries, Inc., Plant Nutrient Division.

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Gabriel
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Re: F.A.O.: Gabriel, The Hell Better Aeroengineer

Postby Gabriel » Fri Nov 16, 2018 8:09 pm

No, sorry.
Not even impressed with that seemingly stable fall?
A lot of objects with random shapes and mass distribution tend to enter and assume a stable spin when falling.

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Re: F.A.O.: Gabriel, The Hell Better Aeroengineer

Postby 3WE » Fri Nov 16, 2018 9:30 pm

No, sorry.
Not even impressed with that seemingly stable fall?
A lot of objects with random shapes and mass distribution tend to enter and assume a stable spin when falling.
Sucked the joy right out of it...Ok, I guess you are correct. Thanks.

I am still impressed at the very slow rotation...and I THINK it is real time as the flame flashes occur rapidly...and I still think I should see some sort of oscillation as opposed to the steady spin.
Commercial Pilot, Vandelay Industries, Inc., Plant Nutrient Division.


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