Principles

Question 1

Explain fluid compressiablity

Answer 1

Fluids are considered to have no to little compressiablity

Question 2

What is pressure measured in

Answer 2

PSI

Question 3

Define Pascal’s law

Answer 3

“When force applied to a fluid within a confined space the resulting pressure is felt equally in all directions and at right angles to the confining space”

Question 4

30ilbs of force applied to a 2 Sq inch surface. How much psi is there

Answer 4

15 PSI

F/A = P

Question 5

Bramahs principle

Answer 5

Under given load the smaller the area it acts upon the greater the pressure is produced

The greater the area under pressure the greater the force avaliable.

Question 6

2 advantages of hydraulics sys over mechanical system

Answer 6

Ease to transmitt force over large distances

Large gains in Mechanical advantage are possible

Question 7

Which has an impact on static pressure? Height or volume of container

Answer 7

Height

Question 8

Define viscosity

Answer 8

Internal resistance to flow. (How thick a liquid or fluid is)

Question 9

Charactistics when determine a fluid for a system

Answer 9

Viscosity
Chemical stability
Flash point
Fire point

Question 10

Open or closed hyd systems used in aviation

Answer 10

Closed

Question 11

Explain difference between open and closed centre’s system

Answer 11

Open centre selector valves are in series.

Closed they are in parrallel