A Lagit question on a Bakki Shower Installation

[Valarc]

I TEACH college kids this stuff... if I couldn't do the math I'd be in a world of trouble

As far as the media changing the velocity - it's hard to say. It would certainly decrease the total velocity change, but it's quite likely it would still be accelerating within the shower. It would be darn complicated to try to calculate the difference!

That's a big reason why I went with the energy-based calculation instead of acceleration. Every time the water splashes or changes direction, it loses some energy, and hence there's less kinetic energy available at the end for the velocity of the water. As I said, everything I did was a theoretical maximum - best case scenario.

[D@z]

As already stated, the water is accelarating throughout the media trays. The bottom tray receives the water at the highest velocity and not only that but the cleanest water at the highest velocity hence its effectiveness is not simply a linear improvement of 1/4 over a three teir system.

[Valarc]

Based on what data, daz? It really bothers me how these things are stated as an absolute fact. The cleaner water part I can buy, but whether the very small incremental change in velocity has any meaningful effect is very questionionable. What I calculated was a complete theoretical maximum... there is no possible way for the water to be gaining more than that. In reality, due to the presence of the media, the real velocity change is going to be MUCH less.

I'm really starting to get frustrated with the way people state something as a fact without ever having tested it. If you think that's why it works, that's great - it's a theory, an idea, a hypothesis... but it's NOT a fact.

[junglegeorge12]

Actually val, your equation may apply but there is something more simple than that at work. As you stated, the water hitting the media will slow it down. Since the flow rate feeding it does not slow up, you have a small accummulation or buildup, then this little thing called weight and gravity take over and the water accelerates simply based on accumulation and weight. Any equations that apply would have to factor in water weight, flow rates per sq/in. and resistance to downward flow the media causes. That is why a taller tower with less surface area per gallon/min. of flow rate would enhance acceleration. More buildup of weight more quickly. Your equation would apply as you said, to an empty tower in a vaccum. So since our towers are not empty and we are not operating in a vacuum, it appears your application of science was a textbook mistake, and great for a classroom, but the world does not operate inside a classroom (although FIR does)!Flawed thinking is and interesting thing, and as a teacher of mine once put it, "If someone knew they were deceived, they wouldn't be anymore."

[gregbickal]

I thought when I was jumping out of airplanes that they told us we fell at like 20feet per second or something.

I thought that the rate of speed that anything fell was constant. Boy, maybe I should have went to college

[junglegeorge12]

actually greg you do accelerate when jumping, how fast depends on weight, gravitational pull, and resistance. Once you reach peak speed, all you have to do to go faster is 'dive'(or carry alot of weight so you can go faster). Ever stack a buddy right on your back with the same downward surface area to see if you go faster???

[gregbickal]

What happend to Newton and the apple? I thought that if you dropped an apple and a bowling ball from the same height that they both hit the ground at the same time?

[Mike T]

Greg:

Your Quote:
"This reminds me of the time when I was jumping out of airplanes in the military. Do you fall faster if you jump from higher up.... NOPE. Gravity is constant."

This would only be true if you're on a static line, during a free fall, however, your speed increases until you reach Terminal Velocity which is 125mph...If you then assume a full delta you can reach speeds in excess of 200mph... Flare out into a fishbone and you can actually move 2' horizontally for every foot you drop vertically...You can FLYYYYYYYYYYYY!!!!

Back to the Bak Set Up, I tend to agree w/ Luke about the cleansing through each tray...didn't think about that aspect when I asked my question...

Aloha! Mike

[James P]

I think Luke and valac have it right- its not about velocity or even speed as a isolated or immediate cause and affect. In my opinion, It is about drenching all media surface, 'complete flushing insurance' , massive expose of water volume to degassing and maybe ( ?) some benefit of pulverizing macro organic detritus?

This is why I wanted Mike S to describe to me WHY speed through media is so important as he sees and understands it.

Mike I'm not enticing you into a trap here. I'm just trying to understand what your take on speed through the media is.

[D@z]

Quote: Originally Posted by Valarc Based on what data, daz? It really bothers me how these things are stated as an absolute fact. The cleaner water part I can buy, but whether the very small incremental change in velocity has any meaningful effect is very questionionable. What I calculated was a complete theoretical maximum... there is no possible way for the water to be gaining more than that. In reality, due to the presence of the media, the real velocity change is going to be MUCH less. I'm really starting to get frustrated with the way people state something as a fact without ever having tested it. If you think that's why it works, that's great - it's a theory, an idea, a hypothesis... but it's NOT a fact.

Not based on any data or facts, nowhere did I ever claim that it was. Its purely my opinion, posted on an opinion board. I have better things to do with my time than to go into it in any more detail than that. Being a scientist working in a field which is very flow orientated I could quite easily model a shower system with a piece of software called FLUENT, and give you your facts but as I say, I realy dont care enough to do that.

If you wish to prove conclusively that I'm wrong then please feel free but so far your crude calculation has backed up my first opinion and you agreed with my second one.

If you cant contribute to a debate amongst HOBEISTS without getting 'frustrated' then I think you maybe should be looking for a more technical forum.