Recent content by aarothepharo

Hello Everyone: Take a look at the following diagram Assuming the coil build above. How would you determine the force pushing-pulling the Neodymium Magnet in the center of the plastic pipe. I know the number of turns, length, amperage are in effect.

Just in case anyone thinks it can't be done. This guy has been building them out of wood for years. http://woodgears.ca/dust_collector/blower_build.html

It looks like nobody has a formula for me so I will use calculus. Thanks for all the help everone

Legolaz: I understand your concern and have already studied the design with a strength stand point. Thanks for the feed back.

Legolaz: I am a Mechanical Engineer. I have found a lot of formulas and probably could use calculus but was wonder if anyone knew of a formula to prevent me from doing it. Any test can be conducted safely and any test that can not be conducted safely should not be conducted. I abide by those rules.

I agree.

Baluncore. I'm building an impeller in a housing however I want to spin it in free air off of a 6.5 HP engine to test if it can spin fast enough without shattering.

Does anybody have any equations that predict the power required to turn an impeller in free air? I am building a wood impeller four blades flat in reference to rotation radiating from central hub. I need to predict the length of the blade to be able match a certain HP.

As we all know, the air we breath is made up of appox... 78% Nitrogen ... 21% Oxygen ... and then traces of other random things. Lets consider that only the oxygen and nitrogen exist so that we neglect the other chemical traces. If I were to fire up a compressor that pumps outside air...

Can anybody help me out? The numbers are not working out for me.

Hey, I'm not getting the numbers to com out right. It says I need less than 1 meter of pex. run the numbers and see what you get: ts = 285.777 K to = 286.333 K ti = 294.111 k

Check My Math: re = (998.21 KG/M3)(0.254 M/S)(0.012573 M) / (1.00 mPa * S) re = 3.18782 Do the Units and the Math look good? v = 30 gallons per hour through .495 ID pipe = .254 M/S

Ok cool. Can you give me reynolds number equation? And the heat transfer equation. I Dont have a heat transfer book.

I want to build a small geothermal cooling unit to cool one small room in my house. If i lay 0.5" pex pipe which is 0.475" ID. The big question is how long does the water flowing in the pex tubing have to stay under ground. Constant ground temperature is about 55 degrees F around my house. I...