Day 1: Energy Convertors Intro

1. Day 1: Energy Convertors Intro • Read pp.2-8 and take your own note on the following: • What is an energy converter? • Are they 100% efficient? Why or why not? • List 4 different types/examples of energy converters • What energy systems do energy converters appear in? • Why is efficiency so important in energy conversion? • How is efficiency calculated? • Name 1 advantage and 1 disadvantage of energy conversion. • List 1 example of energy conversion from the device you built for your 9wk test.

2. Mechanical Energy Convertors What Do They Do and How Different from a Transformer? • change mechanical energy to useful fluid, thermal, or electrical energy • input energy is different from output energy (hence convertor) • if input energy type same as output energy type = force transformer Fluid Energy Energy Convertor Mechanical Energy Electrical Energy Thermal Energy Vane pump Alternator Spin Welder

3. Mechanical Energy Convertors Common Conversion Factors for Energy Units • Many times, rated values for devices must be converted to common energy units • * WHEN ENERGY IS AVAILABLE WORK CAN BE DONE. • WHEN WORK IS DONE, ENERGY IS OFTEN PRODUCED • Therefore Energy=Work or E=W Convertor Energy Units • are based on type of energy output (ex. water pump output is fluid pressure ,so fluid pressure units are used….65psi) • common energy convertor units based on output type are listed below:

4. Mechanical Energy Convertors What’s a Mechanical To Fluid Energy Convertor? • takes a mechanical energy input and converts it into useful fluid energy output • check out the VANE PUMPbelow Gas powered rotating vanes/blades Low Pressure Water In (2psi) High Pressure Water Out (500psi) *Rotational mechanical energy IN(blades) is converted to fluid kinetic energy OUT(water) use to move water out of an area (ex. broken water line) Foot pump* is another good example (input=mechanical , output=fluid(air)) *Demo

5. Mechanical Energy Convertors What’s a Mechanical To Electrical Energy Convertor? • takes a mechanical energy input and converts it into useful electrical energy output • check out the ALTERNATOR below Belt Alternator Shaft converted to Electrical OUT(rotor winding assembly, stator windings) …used to recharge car battery and operate electrical system Rotational mechanical energy IN (belt,alternator shaft)

6. Mechanical Energy Convertors What’s a Mechanical To Thermal Energy Convertor? • takes a mechanical energy input and converts it into useful thermal energy output • check out the SPIN WELDER below Stationary Steel Rod Thermal energy used to fuse components Friction Welding occurs here Rotating Steel rod converted to Thermal Energy OUT (friction between stationary and rotating rod) …used to fuse/weld metal components together Rotational mechanical energy IN (rotating steel rod)

7. Mechanical Energy Convertors Efficiency of an Energy Convertor • no matter what type of energy convertor, they all have efficiency • efficiency is a measure of the extent of useful energy produced • calculated as a % of energy out versus energy in % Efficiency of Energy Convertor Energy Output Work Out = = X100% Energy Input Work In Remember:Energy is work so you could also have: % Efficiency of Energy Convertor X100% HOW EFFICIENT ARE YOU?????

8. Mechanical Energy Convertors Important Equations Related to Energy Convertors Since Energy is Work, here is a summary of work and energy equations: Mechanical Work&Energy: W=FxD W=TxAngle Ek=1/2mv 2 or 1/2Iω2 Fluid Work & Energy: W=∆pxV W=px ∆ V Electrical Work & Energy: E=Pxt W=∆Vxq Thermal Work & Energy: H=mc∆T And of course, don’t forget the EFFICIENC Y equation! Homework: Complete Student Exercises from pg.19 in workbook (copy questions and correct answer)

9. Mechanical Energy Convertors Answers to Student Exercises 1. Output energy 2. Divided 3. C. less than 100% 4. Less than 5. Same 6. A, b, c, All correct 7. Mechanical 8. B 9. D 10. As a minimum, include the converters discussed in presentation (vane pump, spin welder, alternator)