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Hydraulics and Pneumatics

Posted: September 14th, 2009, 7:11 am
by Paradox21
What does it mean for hydraulics and pneumatics to be in a closed system rather than an open one?

Re: Hydraulics and Pneumatics

Posted: September 14th, 2009, 5:46 pm
by htmlfreak
You can't have air from the outside connecting into your pneumatic system, an example is an open tube manometer (well maybe not for this event). As long as your pneumatic/hydraulic system is surrounded or enclosed completely and has no contact with anything outside the let's say "container", you should be fine. Anyone who disagrees please say so :P

Re: Hydraulics and Pneumatics

Posted: September 14th, 2009, 6:23 pm
by andrewwski
I don't have the rules, but that sounds right to me. A closed system would be one that does not let gas or liquid in or out.

Re: Hydraulics and Pneumatics

Posted: September 14th, 2009, 7:40 pm
by DeltaHat
Simple example of a closed hydraulic/pneumatic system: two syringes attached tip to tip with fish tank tubing.

When you push down on one, the other extends. If the system is filled with fluid, then it is hydraulic. If it is filled with air, then it is pneumatic.

Re: Hydraulics and Pneumatics

Posted: September 14th, 2009, 8:29 pm
by fleet130
Examples of open systems might be a waterwheel or windmill. Would an engine that runs on compressed air be considered a closed system if it exhausts the air to the atmosphere as it leaves the engine? What if the exhaust air is captured into a waste accumulator? Is it a closed system if the energy transmitting fluid is recirculated? Example: a fan blowing air to drive a turbine inside an enclosed circular duct.

Re: Hydraulics and Pneumatics

Posted: November 8th, 2009, 9:51 am
by hassan5082508
is it ok to have a co2 canister blow a golf ball? or is that considered an unenclosed system?

Re: Hydraulics and Pneumatics

Posted: November 8th, 2009, 11:45 am
by andrewwski
That wouldn't be a closed system. There's gas leaving the system.

Re: Hydraulics and Pneumatics

Posted: November 8th, 2009, 12:18 pm
by Flavorflav
andrewwski wrote:That wouldn't be a closed system. There's gas leaving the system.
What if the co2 inflated a balloon, though? That should count.

Re: Hydraulics and Pneumatics

Posted: November 8th, 2009, 12:48 pm
by Sir_L_Jenkins
Flavorflav wrote:
andrewwski wrote:That wouldn't be a closed system. There's gas leaving the system.
What if the co2 inflated a balloon, though? That should count.

I would imagine, although you would have to make sure the balloon does not pop, which would cause the CO2 to escape, then it would be an open system and not count.

Re: Hydraulics and Pneumatics

Posted: November 8th, 2009, 1:37 pm
by Uncle Fester
Yesterday at Build-It-Day (Indianapolis), Dark Sabre hooked a windshield washer pump he got from salvage to a large chem-use syringe via plastic tubing. Took all of five minutes to do, including wiring. EASILY pushed out the syringe at a nice and easy speed with plenty of force (read: foolproof use of hydraulics).

Why do risky things that could cost points?