NAVAL SCIENCE 345 INTRO TO NAVAL ENGINEERING

WHAT IS NAVAL ENGINEERING? l “THE TRANSFORMATION OF AVAILABLE ENERGY FORMS INTO FORCES FOR PROPELLING AND OPERATING WARSHIPS AT SEA” l MAKING THE SHIP GO

WHAT’S THE POINT? l YOU are going to be a naval engineer l “Technically and tactically proficient” l Safety of ship and crew l 2/C Cruises & Warfare schools l BE THE HERO!

Administrative Matters l Textbooks –Introduction to Naval Engineering –Principles of Naval Engineering l Syllabus –Overview –Grading policy –Responsibilities

Individual Presentation l Independent research l Expand on class topics –Applications –Technological developments l Ability to deliver a 10 min. brief –PowerPoint recommended –Make it interesting –Preview with me

PRINCIPLES OF MEASUREMENT INTRODUCTION TO NAVAL ENGINEERING

What does it mean to measure? l IT’S A COMMON LANGUAGE l PROVIDE INDICATION OF PLANT PERFORMANCE l PROVIDE INPUT FOR ALARMS l HOURLY LOGS FOR RECONSTRUCTION(WHAT JUST HAPPENED AND WHY)

What do we measure? l LENGTH (in, ft, yd, mi, nm) l AREA (in 2, ft 2 ) l VOLUME (ft 3, gal) l MASS (lbm) l FORCE or WEIGHT (lbf, tons, lt) l TIME (s, min, h) l VELOCITY (ft/s, mph, kts) l ACCELERATION (ft/s 2 ) l PRESSURE (psia, psig, in of Hg, in of H 2 O) l TEMPERATURE ( o F, R) l ENERGY (BTU, ft-lbf) l TORQUE (ft-lbf, in-lbf) l POWER (ft-lbf/s, ft-lbf/min, BTU/h, hp, MW)

TEMPERATURE l A measure of a substance’s internal kinetic energy l [Simply stated] The degree of hotness or coldness of a substance, as measured on a thermometer

Temperature Conversions l Fahrenheit – o F = (9/5 o C) + 32 l Celsius or Centigrade – o C = 5/9 ( o F - 32) l Rankine –R = o F l Kelvin –K = o C

Temperature Measuring Devices l Expansion Thermometers –Liquid in glass –Bimetallic –Filled system / distant reading l Pyrometers –Thermocouple –Resistance –Radiation and optical pyrometers

Liquid in Glass Thermometer

Bimetallic Expansion Thermometer

Distant Reading Thermometer

Thermocouple

Resistance Temperature Device

Radiation Pyrometer

PRESSURE l Force exerted on a unit area l Measured in psia, psiv or psig (other units include atm, in Hg, mm Hg) l Atmospheric pressure at sea level is 14.7 psia, 0 psig, 1 atm, in Hg, 76.0 mm Hg

PRESSURE l WHICH EXERTS MORE PRESSURE, A 2000 POUND ELEPHANT WHICH HAS A.5 FT RADIUS FOOT, OR A 150 POUND WOMAN ROCKING ON HER HEELS WITH A.5 IN RADIUS? l ELEPHANT- 4.4 POUNDS PER SQUARE INCH WOMAN POUNDS PER SQUARE INCH

Gage and Vacuum versus Absolute Pressure l Absolute Pressure = Atmospheric Press. + Gage Press. l Vacuum = Atmospheric Press. - Absolute Press. Don’t have absolute pressure gages

Manometer Pressure Measuring Devices

Bourdon Tube Pressure Measuring Devices

Bourdon Tube Pressure Measuring Devices

Bellows Gage Pressure Measuring Devices

ACCURACY l KNOWING THE ACCURACY IS JUST AS IMPORTANT AS KNOWING THE APPARENT VALUE l CALIBRATION WITH A STANDARD l CRUCIAL PERIODIC MAINTENANCE…OUR GRIP ON REALITY

Example Problems l Convert the following to o F: –100 o C –100 K –100 R l Convert the following to psia –100 psig –10 psiv