2. Naval Ship Systems Naval Engineering

3. Fundamentals of Thermodynamics I Principles of Measurement

4. References Required: Introduction to Naval Engineering, Appendix A, pp. 511-516 Optional: Principles of Naval Engineering, pp. 11-16

5. Objectives Know basic metric to USCS conversion factors and techniques. Comprehend the relationship between relative, absolute, gage, and vacuum pressures. Comprehend the operation of devices used in the Navy to measure temperature and pressure.

6. Purpose of Measuring Devices Why are they essential to proper operation of engineering systems?

7. Measurement Systems SI – International standard for a majority of the world and almost all the scientific communities – Typical Units Meters Liters kilograms

8. Measurement Systems United States Customary System (USCS) – a.k.a “the English system” – Typical Units Feet Gallons Pounds

9. Force, Weight, and Mass

10. Mass ≠ Weight – Mass – an object’s resistance to acceleration – Weight – the force exerted by an object due to gravitational acceleration Weight is dependent on location, mass is not.

11. Properties Properties define a system Two varieties – Extensive – Intensive

12. Properties Extensive Properties – Depend on the quantity of matter present – Extensive properties are additive – Examples Mass Volume

13. Properties Intensive Properties Independent of the quantity of matter present

14. Extensive vs. Intensive Extensive properties can almost always be made intensive by dividing the property by mass. – Examples: Specific heat capacity specific volume Using intensive properties can simplify system analysis. How

15. WHAT IS TEMPERATURE? An indication of the internal energy contained in a substance. – Monatomic Gases: Linearly proportional

16. WHAT IS TEMPERATURE? – Poly-Atomic Gases: translational, rotational and vibrational kinetic energy. Temp is a measure of but not directly proportional to internal kinetic energy.

17. Measurement of Temperature Relative Scales – Fahrenheit (°F) – Celsius (°C) Absolute Scales – Rankine (°R) – Kelvin (K)

18. Temperature Relationships (°F) = 9/5*(°C) +32 (°C) = 5/9*[(°F) –32] (°F) = (°R) – 459.67 (°C) = (K) – 273.15

19. Principle of Operation Temperature Devices Expansion Thermometers – Liquid in glass – Bimetallic – Filled system/distant reading Pyrometers – Thermocouple – Resistance – Radiation and optical pyrometers

20. Expansion Thermometer Liquid in Glass Bimetallic Filled System/Distant Reading

21. Expansion Thermometer Liquid in Glass Bimetallic Filled System/Distant Reading

22. Expansion Thermometer Liquid in Glass Bimetallic Filled System/Distant Reading

23. Expansion Thermometer Liquid in Glass Bimetallic Filled System/Distant Reading

24. Pyrometers Thermocouple Resistance Radiation and Optical

25. Pyrometers Thermocouple Resistance Radiation and Optical

26. Pyrometers Thermocouple Resistance Radiation and Optical

27. Pyrometers Thermocouple Resistance Radiation and Optical

28. Measurement of Pressure Definition: Force per unit area Units of measurement – Pounds force per square inch (psi) – Inches Hg or inches H 2 O (“Hg) – Atmospheres (atm)

29. Pressure Relationships Gage pressure (PSIG) Absolute pressure (PSIA) Vacuum pressure (PSIV) or (in Hg) Differential Pressure (PSID) Atmospheric pressure (14.7 psi)

30. Pressure Relationships P abs = P atm. + P g P vac = P atm. – P abs

31. Operation of Pressure Measuring Devices Manometers Bourdon tube Bellows gage

32. Operation of Pressure Measuring Devices Manometers Bourdon tube Bellows gage

33. Operation of Pressure Measuring Devices Manometers Bourdon tube Bellows gage

34. Operation of Pressure Measuring Devices Manometers Bourdon tube Bellows gage

35. Define temperature and pressure. Describe the scales used to measure temperature, including reference points and relationship to one another. Describe the relationship between absolute, atmospheric, gage and vacuum pressures. Describe the principles of operation for each type of temperature and pressure measuring device.

36. Questions?