Egan's Chapter 6 part 2
What is the critical temperature of liquid oxygen?
-118.8 C
Air consists of 21% Oxygen and 79% Nitrogen. Find the partial pressure of each at 760mmHg (normal atmospheric pressure).
.21x760mmHg= 160 mmHg .79x760mmHg= 600 mmHg
According to Dalton's law, a gas making up 25% of a mixture would exert what percent of the total pressure?
25%
1 atm = ? mmHg
760 mmHg
What is fluidics?
A branch of engineering applying hydrodynamics principles in flow circuits; devices have no moving parts.
What is transitional flow?
A mixture of laminar and turbulent flow.
What does jet entrainment do?
A pressurized has passed through the jet where beyond is an air entrainment port. The force of the gas flowing through the jet drags the non moving gas (room air) into the stream of O2.
What does the law of continuity mean?
As the cross section of a tube gets smaller, the velocity of the fluid increases and vice versa.
What does the Bernoulli principle state?
As the flow increases, the pressure in the fluid will decrease as there is less pressure on the walls.
What is Henry's Law?
At constant temperature, the amount a certain gas will dissolve in a certain type of fluid and it's the fluids volume is directly proportional to the partial pressure of that gas in equilibrium with that fluid; as temperature rises solubility decreases and vice versa.
How can a gas be liquified?
Being cooled to below its boiling point; being cooled to less than its critical temperature and then compressed.
Fill in the blanks: High temperatures ______________ gas solubility and low temperatures ____________ gas solubility.
Decrease, increase
According to Poiseuilles Law, doubling the tube radius (increases or decreases) the the resistance by a factor (or 2^4 = 16)?
Decreases; increasing radius decreases resistance.
What is laminar flow?
Fluid moving in discrete cylindrical layers or streamlines.
What is the formula for partial pressure?
Fractional concentration x total pressure
What is gas tension?
Gas pressure in a liquid.
What is a vapor?
Gaseous state of a substance that coexists with its solid or liquid state at room temperature and pressure.
How are gases similar to liquids?
Gases exert pressure, are capable of flow, and exhibit the property of viscosity.
As a liquid is warmed, the kinetic activity of any dissolved gas molecules (increases or decreases?) which (increase or decreases?) the escaping tendency's of the molecules and partial pressure.
Increases; increases.
What are the three patterns of flow through tubes?
Laminar, turbulent, and transitional flow.
The more a gas is cooled below its critical temperature, the (more or less?) pressure will be needed to liquefy it.
Less
A fluid that is moving faster through a pipe has more or less pressure?
Less pressure; the slower fluid moves through a pipe the more pressure it puts on the walls versus when fluid is moving faster, it puts less pressure on the walls
Can you see molecular water?
No
What are the three basic assumptions of gas laws?
No energy is lost during molecular collisions; the volume of the molecules themselves is negligible; and no forces of mutual attraction exist between these molecules.
What is Poiseuille's Law?
Predicts the pressure required to produce given flow; Indicates that resistance is very sensitive to changes in tube radius.
What pressures are considered hyperbaric pressure? What are hyperbaric chambers used for?
Pressure above atmospheric; used to depressurize sea-divers (usually).
When a fluid is flowing out of the end of a tube, you see a progressive decrease in fluid pressure as fluid flows through the tube due to what?
Resistance.
What is flow?
The bulk movement of a substance through space.
What is the combined gas law?
The combination of all other gas laws; PV=nRT
What do the critical temperature and critical pressure represent?
The critical point.
The pressure exerted by a liquid in motion depends on the nature of what?
The flow itself.
The rate of diffusion of a gas is inversely proportional to what?
The gases molecular weight.
What is critical temperature?
The highest temperature at which a substance can exist as a liquid.
What is turbulent flow?
The loss of regular streamlines; forms irregular eddy currents in a chaotic pattern. Reynolds number NR= v x d x 2r/h
What is flow resistance?
The pressure difference between two points along a tube at a given flow.
What is partial pressure?
The pressure exerted by a particular gas in a mixture of gases; totals must add up to 100% or atmospheric pressure.
What is critical pressure?
The pressure needed to maintain equilibrium between the liquid and gas phases of a substance at critical temperature.
What is hydrodynamics?
The study of fluids in motion.
What is Dalton's Law?
The total pressure of a mixture of gases must equal the sum of all partial pressure of all component gases.
In the Bernoulli principle, why does pressure decrease as flow increases?
There are fewer molecular collisions against the wall because of the increased flow.
Why must gas law calculations take into account the presence of water vapor?
Water vapor occupies space, so the dry volume of gas at a constant pressure and temperature is always smaller than its saturated volume and vice versa.
What is the Coanda effect?
When fluid flows through a small orifice with a properly contoured downstream surface;the atmospheric pressure "locks" it against the downstream surface.
What does the Venturi effect say?
When fluid is flowing through a pipe and flows through an even smaller pipe, the velocity increases and the pressure decreases.
What is Gay-Lussac's Law?
When volume is constant, pressure and temperature are directly proportional to one another; temperature goes down, pressure will go down and vice versa; P1/T1=P2/T2
What is Boyle's law?
With constant temperature, volume and pressure are indirectly proportional; pressure goes up, volume goes down and vice versa; P1V1=P2V2
What is Charles' Law?
With pressure constant, the volume of a gas is directly proportional to its temperature; higher temperature, higher volume; V1/T1=V2/T2
Can gases dissolve in liquids?
Yes
How can you alter the amount of entrained air?
You can get larger or smaller entrainment ports, depending if you want to entrain more or less air, or changing the jet into a larger or smaller one.
I'm terms of entrainment, if you get a smaller jet, do you get lower or higher gas velocity and more or less entrainment?
You get higher velocity and more entrainment as openings are larger.
In terms of entrainment, if you get a larger jet, do you get lower or higher gas velocity and more or less entrainment?
You get lower gas velocity and less entrainment as openings are smaller.
