physics tuba question

[Chuck(G)]

http://www.coolquiz.com/trivia/explain/ ... _balls.asp

[tubeast]

My server doesn´t allow me to open the link Chuck provided, but here´s the explanation our fluid dynamics professor provided:
In addition to the effect Rick Denney mentioned, the dimples make sure the airflow around the ball is turbulent rather than laminar even at compareably low speeds.
It´s true that turbulent airflow has more internal resistance than laminar flow, but with laminar flow the "air-shadow" (space which the flow around the ball doesn´t reach because air already is there) behind the ball expands with distance from the ball and adds to its drag resistance.
With turbulent flow, the air-shadow is much narrower, offering less resistance, which makes the ball loose less dynamic energy on its path.

This effect is used in volleball, too. When serving, the players try to give the ball a speed great enough so there will be tubulent flow. The ball goes almost on curved, but basically horizontal line until it lost so much speed that the flow switches to laminar. All of a sudden the ball will change its path, falling much faster.

As to tubas: I´m afraid dimples won´t have that much effect because especially at the end of the tube the air flow is incredibly slow. Plus, the geometry of the horn that has effect on air resistance won´t change, as opposed to the ball.

[windshieldbug]

What was that custom model of F. E. Olds trombone that had that hammered finish?

I believe both the Olds trombones and trumpets with the hand-hammered 'dimpled' bells were known as the "Military" models;
Since there is no real airflow I can only imagine that it was justified by the overtones created/cancelled by this treatment.

[iiipopes]

My Besson has had the dents hammered out of it so many times before I got it that it looks like a hammer peen finish! Doesn't affect tone, as the valves are perfect. As a matter of fact, a band director friend said if he had found it first, he would have bought it for his band!

[Rick Denney]

http://www.coolquiz.com/trivia/explain/ ... _balls.asp

So it is the same. Cool.

Rick "who'll loan Chuck his picking hammer" Denney

[hbcrandy]

From the side of practicality, how does one propose to buff and degrease the inside of the tuba when the smaller tubing is about 3/4" in diameter and several feet long?

[windshieldbug]

From the side of practicality, how does one propose to buff and degrease the inside of the tuba when the smaller tubing is about 3/4" in diameter and several feet long?

Using a very small labor force

[iiipopes]

It's expensive, but if you can find a tech with an ultrasonic bath it works great! I just haven't come up with the $150 yet to do mine.

[Donn]

Wonder if you could get the ball magnets with a rubber exterior?

[windshieldbug]

Teflon.