Solar chimney thoughts

Question: if I took a tube, let’s say 6 inches diameter by 10 feet long, stood it on end so it would stay up but had a way to get good airflow off the ground:
Would it move air up like a solar chimney even if it wasn’t in sun?  
How about in the middle of a chilly night?
What if it was 20 feet long?
How about at a 45 degree angle?

What is the lowest requirements for making air flow up a tube?

How much air flow?  Heat differential is the only requirement.  Simple black pipe in full sun will do a little although not much(as in you can barely feel the air flow if you are lucky.  Is round a requirement?  A rectangle with more surface area to the sun will do more, because of more heat  Assuming round it a requirement can you add a bigger reflector behind it to give more heat or can you give it a clear front to provide air isolation so it gets hotter?

Linking to my collector write up simply because it might give you a feel for what you might expect.  The early testing included some convection numbers.

Thermal collector panel

What is the goal or application?

I am a fan of passive non-electric solutions, but the price of pipe and materials is so high these days that solar electric solutions are often cheaper.