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Copy the sentences in your notebook. Fill in the blanks using the terms below:

1. _______ is how much space an object occupies.

2. _______ is a force applied over an area.

3. _______ is a system in which no fluid can enter or leave.

March 2, 2010

DRILL

Pressure Closed System Volume

3. 1.2.

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UNIT 3 – Engineering Design

Engineering, the systematic application of mathematical, scientific, and technical principles, produces tangible end products that meet our needs and desires.

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UNIT 3 – Engineering Design

a. Getting familiar with the Big Idea

b. The Design Process

c. Core Technologies

d. Mechanical Technology

e. Electrical Technology

f. Reverse Technology

g. Fluid Technologyh. Thermal Technology

i. Optical Technology

j. Materials Technology

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Fluid Technology

PURPOSE OF SUB-UNIT

• To familiarize students with the functioning and applications of fluid technology systems.

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• The technology of using fluid, either gas (pneumatics) or liquid (hydraulic) to apply force or to transport.

Example applications: •Air brakes on a truck, •Tires on a car, •Airfoils on an airplane, •Warm-air heating ducts, •Hydraulic jack, •Plumbing in a school•Hydro-electric dam

What is Fluid Technology?

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• Blood flow in capillaries (only a few micro-meters in diameters)

• Crude oil across Alaska through 800-mile-long, 4-ft diameter pipe

• Streamlined, smooth surfaces of airplanes for efficient air flight

• Dimpled, rough surfaces of golf balls for efficient flight• Why does a stream of water from a faucet sometimes

appear to have a smooth surface, but sometimes a rough surface?

• How does aerodynamic design of cars and trucks affect gas mileage?

Other applications of Fluid Technology…

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• College engineering text definition: – a substance that deforms continuously when acted on by a

shearing stress of any magnitude• Standard definition:

– a substance (as a liquid or a gas) that conforms to the shape of its container

• Gases are compressible, liquids are not

• Fluid Systems have 2 things in common:– They contain a fluid, either gas (pneumatics) or liquid

(hydraulics)– They contain a pressure difference that creates a net force

What is a FLUID?

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• Area – a surface within certain boundaries– Typically 2-dimensional

• Volume – the amount of space an object occupies – 3-dimensional

• Force – a push or pull• Pressure – a force applied over an area

FLUID PRINCIPLES

What is the area of the portion of this piece of lumber that sits on the floor?

(Convert all units to inches first) 4” x 12” = 48 square

inches

What is the total volume of this piece of lumber?

(Convert all units to inches first)

48” x 2” = 96 cubic inches

Your teacher stands on this piece of wood on the floor.

What is the pressure applied to the floor beneath the wood?

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• Pressure is a force applied over an area.• What are some typical units for pressure?

– Psi (pounds per square inch)

• Pressure = Force / Area

FLUID PRINCIPLES

A = 48 square inches

Your teacher (weighing 165 pounds) stands on this piece of wood on the floor.

What is the pressure applied to the floor beneath the wood?

F = 165 lbs.

P = F / A

P = 165 lbs / 48 in2

P = 3.44 psi

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1. Create a chart for data in your notebook.

2. Record the following experimental data.Round to nearest 10th

AIR

Volume (ml) Pressure (psi)

Principles of Fluid Technology

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1. Graph your data

2. Make volume the independent

3. Make pressure the dependent

4. Start both at zero

Principles of Fluid Technology

X-axis

Y-axis

Volume (mL)

Pre

ssu

re

(psi

)

What is the data range?

Volume: 9-30 mL

Pressure: 17-55 psi

0 5 10 15 20 25 30

60 55 50 45 40 35 30 25 20 15 10 5

Principles of Fluid Technology

Pressure (psi)

0

10

20

30

40

50

60

0 5 10 15 20 25 30 35

Volume (mL)

Pre

ssu

re (

psi

)

1. Your graph should like the graph below.

2. What can you say about the relationship between volume and pressure?

As volume increases, pressure decreases

3. Is this a proportional or inversely proportional relationship?

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