Estimation CONFIDENTIAL COPYRIGHT 2018 Estimation Course Skills to

Estimation CONFIDENTIAL COPYRIGHT © 2018

Estimation Course Skills to be gained today - Gain reference points in various scales of measurement - Use these references to intuitively know if the answer to a calculation is right or wrong CONFIDENTIAL COPYRIGHT © 2018

Estimation – Benefits of a reference framework Intuition As an engineer you are often required to use your own insight and intuition to determine whether the answer to a calculation is correct, or wildly wrong. Eg. You are calculating the terminal velocity of a sprinter in a 100 m race and your answer is 5 m/s – How do you know if this is a reasonable answer? Framework The answer is that you are relying on your framework of knowledge and experience to guide you. i. e. In the above case, measurements and speeds that you are already familiar with. The purpose of this course is to provide you with more reference points in the scales of; velocity, temperature, pressure, voltage, current, mass, force, and inertia and so help you sanity check answers to calculations before you provide them to others. CONFIDENTIAL COPYRIGHT © 2018

Estimation – Velocity (m/s) Average walking speed = 1. 4 m/s 30 mph speed limit = 13. 4 m/s 50 mph speed limit = 22. 4 m/s 70 mph speed limit = 31. 3 m/s Skydive terminal speed = 73. 7 m/s World record driven wheel car (2018) = 200. 6 m/s (Challenger 2) World record jet powered car (2018) = 341. 1 m/s (Thrust SSC) Speed of sound (at sea level) = 343 m/s Q. What is the terminal speed of an Olympic sprinter? CONFIDENTIAL COPYRIGHT © 2018

30 (at nd /s sou 43 m of 3 ed l) = Spe eve l red we sea po jet m/s ord 41. 1 3 rec rld 8) = Wo (201 SC) S car rust (Th eel wh ven dri m/s ord 00. 6 2 rec rld 8) = ) Wo (201 ger 2 car allen (Ch l ina erm /s et 7 m div 73. Sky ed = spe /s 3 m 31. it = /s lim 4 m ed pe 13. hs t= mi mp d li age peed 70 e pe ver g s A hs lkin s mp wa. 4 m/ =1 Estimation – Velocity (m/s) Q. You have just re-calibrated a radar gun and wish to use it to measure the terminal velocity of some Olympic sprinters. The first test reading is 5 m/s – Is the reading true or false? FALSE TRUE Try Again 100 m sprint terminal speed = 12. 2 m/s CONFIDENTIAL NEXT >> COPYRIGHT © 2018

30 (at nd /s sou 43 m of 3 ed l) = Spe eve l red we sea po jet m/s ord 41. 1 3 rec rld 8) = Wo (201 SC) S car rust (Th eel wh ven dri m/s ord 00. 6 2 rec rld 8) = ) Wo (201 ger 2 car allen (Ch l ina erm /s et 7 m div 73. Sky ed = spe /s 3 m 31. it = /s lim 4 m ed pe 13. hs t= mi mp d li age peed 70 e pe ver g s A hs lkin s mp wa. 4 m/ =1 Estimation – Velocity (m/s) Q. You are on a powered rubber-dinghy in the sea and spot a SHARK fin in the distance, heading your way and looking hungry. You need to contemplate your strategy – speed (out-run it) or agility (dodge it). You know the top speed of the boat is 15 m/s, which is pretty quick on water, and choose to out-run the shark – is this a good plan? NO YES Try Again Top speed of a shark = 19. 7 m/s CONFIDENTIAL NEXT >> COPYRIGHT © 2018

30 (at nd /s sou 43 m of 3 ed l) = Spe eve l red we sea po jet m/s ord 41. 1 3 rec rld 8) = Wo (201 SC) S car rust (Th eel wh ven dri m/s ord 00. 6 2 rec rld 8) = ) Wo (201 ger 2 car allen (Ch l ina erm /s et 7 m div 73. Sky ed = spe /s 3 m 31. it = /s lim 4 m ed pe 13. hs t= mi mp d li age peed 70 e pe ver g s A hs lkin s mp wa. 4 m/ =1 Estimation – Velocity (m/s) Q. You are responsible for designing a multi-stage radial-compressor system. One of your colleagues presents a calculation that the air-speed at the entry to the final compression stage is 360 m/s. Is this calculation answer plausible? NO YES Try Again The inlet would be choked as the speed of sound is only 343 m/s NEXT >> CONFIDENTIAL COPYRIGHT © 2018

30 (at nd /s sou 43 m of 3 ed l) = Spe eve l red we sea po jet m/s ord 41. 1 3 rec rld 8) = Wo (201 SC) S car rust (Th eel wh ven dri m/s ord 00. 6 2 rec rld 8) = ) Wo (201 ger 2 car allen (Ch l ina erm /s et 7 m div 73. Sky ed = spe /s 3 m 31. it = /s lim 4 m ed pe 13. hs t= mi mp d li age peed 70 e pe ver g s A hs lkin s mp wa. 4 m/ =1 Estimation – Velocity (m/s) Q. You are creating an ‘arresting device’ which must be capable of halting a Boeing 747 at the end of a run-way on takeoff. The calculations you are presented with show an assumption that the entry speed into your device is 82 m/s. Is this plausible? YES NO Try Again Fully laden 747 take-off speed is typically 82. 2 m/s CONFIDENTIAL NEXT >> COPYRIGHT © 2018

30 343 1. 4 COPYRIGHT © 2018 CONFIDENTIAL (at nd /s sou 43 m of 3 ed l) = Spe eve l red we sea po jet m/s ord 41. 1 3 rec rld 8) = Wo (201 SC) S car rust (Th 82. 2 m/s Boeing 747 take-off 12. 2 m/s Sprinter top speed eel wh ven dri m/s ord 00. 6 2 rec rld 8) = ) Wo (201 ger 2 car allen (Ch 343 m/s Orifice choke speed (Air) 19. 7 m/s Shark top speed l ina erm /s et 7 m div 73. Sky ed = spe /s 3 m 31. it = /s lim 4 m ed pe 13. hs t= mi mp d li age peed 70 e pe ver g s A hs lkin s mp wa. 4 m/ =1 Estimation – Velocity (m/s)

Estimation – Temperature (C) Yakutsk, Russia Average -50 deg C in Winter Death Valley, California Average 47 deg C in Summer CONFIDENTIAL COPYRIGHT © 2018

Estimation – Temperature (C) l tee 0 s t= 413 oin g p , 370 ltin +1 me ion ust = mb ure l Co rat tro pe Pe tem gas 00 1, 0 l tee p 0 s 413 g tem 1 rin = +87 pe tem m niu mi ing Alu melt 50 6 =+ int po in res e oxy br Ep on fi lass g rb (ca trix) ition ma trans +180 p= tem an -50 ssi Ru nter = Wi Q. You are conducting a design review of a CVT, which uses a special oil, that is too viscous to pour below – 20 deg C, will your OEM clients accept this? YES NO Try Again Automotive requirements are for engine function down to -40 deg C NEXT >> CONFIDENTIAL COPYRIGHT © 2018

Estimation – Temperature (C) l tee 0 s t= 413 oin g p , 370 ltin +1 me ion ust = mb ure l Co rat tro pe Pe tem gas 00 1, 0 l tee p 0 s 413 g tem 1 rin = +87 pe tem m niu mi ing Alu melt 50 6 =+ int po in res e oxy br Ep on fi lass g rb (ca trix) ition ma trans +180 p= tem an -50 ssi Ru nter = Wi Q. You are designing a carbon-fibre supersonic aeroplane that travels at Mach 3, will it survive the heating effect of friction from air on its leading edges? YES NO Blackbird SR 71 reached surface temperatures of 338 deg C, which would melt the epoxy resin holding the carbon fibres together (180 deg C) CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Estimation – Temperature (C) l tee 0 s t= 413 oin g p , 370 ltin +1 me ion ust = mb ure l Co rat tro pe Pe tem gas 00 1, 0 l tee p 0 s 413 g tem 1 rin = +87 pe tem m niu mi ing Alu melt 50 6 =+ int po in res e oxy br Ep on fi lass g rb (ca trix) ition ma trans +180 p= tem an -50 ssi Ru nter = Wi Q. You are designing a heat-shield mounting bracket, which attaches directly to the engine, can it be made from engineering plastic PA 66 -CF 30 (melting point 260 deg C)? YES NO Temperatures behind the heatshields on engines are typically up to ~250 deg C, this doesn’t leave much safety factor CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Estimation – Temperature (C) l tee 0 s t= 413 oin g p , 370 ltin +1 me ion ust = mb ure l Co rat tro pe Pe tem gas 00 1, 0 l tee p 0 s 413 g tem 1 rin = +87 pe COPYRIGHT © 2018 CONFIDENTIAL tem m niu mi ing Alu melt 50 6 =+ int po in res e oxy br Ep on fi lass g rb (ca trix) ition ma trans +180 p= tem an -50 ssi Ru nter = Wi 338 Deg C Leading edge temperatures Blackbird SR 71 -40 to +150 Automotive oil requirements 250 Deg C Temp behind engine heatshields

Estimation – Pressure (Bar) (Gauge) Air pressure at STP = 0. 013 Bar (Gauge) Mains water = 10 m head = 0. 981 Bar (Gauge) Work-shop air-lines = 7 Bar (Gauge) Gear pumps = ~300 Bar (Gauge) max Piston pumps = ~450 Bar (Gauge) Engine water pump pressure = ~ 7 Bar (Gauge) Absolute Vacuum = -1 Bar (Gauge) CONFIDENTIAL COPYRIGHT © 2018

Ge 7 s= ine ir-l pa ho rks 81 Wo 0. 9 =+ 13 ter 0. 0 wa = +. 3 ins e 0 r Ma =ssu pre cuum -1 a ric = V he um ugh osp o acu R l. V Atm Estimation – Pressure (Bar) (Gauge) ar 300 il is o Ax 450 nt Be mp = pu = mp pu oil Ful Q. You are designing a cylinder head stud and have calculated the peak combustion pressure as 300 Bar, does this seem reasonable? YES NO Try Again Diesel engine peak pressure ~ 220 Bar Petrol engine peak pressure ~ 120 Bar NEXT >> CONFIDENTIAL COPYRIGHT © 2018

Ge 7 s= ine ir-l pa ho rks 81 Wo 0. 9 =+ 13 ter 0. 0 wa = +. 3 ins e 0 r Ma =ssu pre cuum -1 a ric = V he um ugh osp o acu R l. V Atm Estimation – Pressure (Bar) (Gauge) ar 300 il is o Ax 450 nt Be mp = pu = mp pu oil Ful Q. You are specifying an oil pump for an automotive transmission system, Max pressure is 40 Bar and flow-rate is 15 L/min, your colleague is suggesting a piston pump, does this seem reasonable? YES NO Gear pumps are more suited to low peak pressures and high flow rates CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Ge 7 p= um 7 rp s= ate -line e w p air gin En sho k 981 r +0. Wo = 13 ter 0. 0 wa = +. 3 ins e 0 r Ma =ssu pre cuum -1 a ric = V he um ugh osp o acu R l. V Atm Estimation – Pressure (Bar) (Gauge) ar 300 il is o Ax 450 nt Be mp = pu = mp pu oil Ful Q. You design a water cooling circuit and calculate the pressure drop across the coolers, pipes, etc to be 9 Bar at full flow rate. Is this OK? YES NO You will never achieve full flow rate, the pump will start to cavitate at the inlet when the pressure drop in the circuit equals the supply pressure CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Ge ar il is o Ax 450 nt Be mp = pu 300 120 to 220 ICE combustion pressure range = mp pu oil Ful 7 p= um 7 rp s= ate -line e w p air gin En sho k 981 r +0. Wo = 13 ter 0. 0 wa = +. 3 ins e 0 r Ma =ssu pre cuum -1 a ric = V he um ugh osp o acu R l. V Atm Estimation – Pressure (Bar) (Gauge) Gear pumps more suitable up to ~150 Bar Water pumps typ 7 Bar (Gauge) output CONFIDENTIAL COPYRIGHT © 2018

Estimation – Current (A) 4 Cylinder ECU, including injectors & coils = 10 A Worldwide multi adapter plug = 3 -5 A Single phase mains plug = 13 A (3. 25 k. W @250 V Europe) Electric motor for mild hybrid system = 333 A (16 k. W @48 V) Electric motor for Battery Electric Vehicle = 150 A (120 k. W @800 V) CONFIDENTIAL COPYRIGHT © 2018

Estimation – Current (A) 48 W, VM hyb = rid 50 333 =1 pte V BE da 0 V ild , 80 ga 13 g= plu 0 ins U = 1 ma C yl E ase 3 -5 4 c r= k. W ph 120 gle 16 k Sin Plu Q. You calculate the peak electrical load from all of the ancillaries on a passenger car as 4. 5 k. W, for your 12 V vehicle, this means 375 A draw – is this reasonable? YES NO High spec vehicles are now trying to move the larger loads onto a 48 V sub-network, to keep currents & hence wire sizes down CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Estimation – Current (A) 48 W, VM hyb = rid 50 333 =1 pte V BE da 0 V ild , 80 ga 13 g= plu 0 ins U = 1 ma C yl E ase 3 -5 4 c r= k. W ph 120 gle 16 k Sin Plu Q. You purchase an electric vehicle with 90 k. Wh of battery, the manufacturer suggests it can be fast-charged in ½ an hour. You install a ‘fast-charger’ in your garage at home. The smart electricity meter says you are drawing 720 A. Is that about what you would expect? YES NO Try Again On a single phase home supply, 250 V x 720 A = 180 k. W (To charge 90 k. Wh in ½ an hour). CONFIDENTIAL NEXT >> COPYRIGHT © 2018

Estimation – Current (A) 48 W, VM hyb = rid 50 333 =1 pte V BE da 0 V ild , 80 ga 13 g= plu 0 ins U = 1 ma C yl E ase 3 -5 4 c r= k. W ph 120 gle 16 k Sin Plu Q. Your CNC machine has a 20 k. W milling head and will be hooked up to a three phase supply. Your installer is about to connect it to the supply using a 100 A fuse-board. Does this seem about right? YES NO 3 -phase supplies are 400 V rated, so you should only need a 50 A fuse. CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Estimation – Current (A) 48 W, 333 CONFIDENTIAL = rid 50 =1 94 A 4. 5 k. W draw on a 48 V circuit hyb V BE pte da 0 V ild , 80 VM k. W ga 13 g= plu 0 ins U = 1 ma C yl E ase 3 -5 4 c r= ph 120 gle 16 k Sin Plu 50 A 20 k. W CNC machine on a 400 V three phase supply 720 A Fast charge 90 k. Wh in ½ hour @250 V COPYRIGHT © 2018

Estimation – Force (N) Grip strength average adult = 300 - 450 N Passenger car ‘Drag’ at top speed of 155 mph = 1500 N Tensile limit of an M 4 steel bolt (12. 9 grade) = 1000 N Downward force on top of piston (120 Bar, 86 mm dia) = 70, 000 N CONFIDENTIAL COPYRIGHT © 2018

o op 450 000 70, 00 olt =3 n= isto h ngt fp tre rag rd r ca 500 nge = 1 sse MPH Pa 5 5 000 @1 =1 4 b it M lim ps sile Gri Ten t on ce For Estimation – Force (N) Q. You calculate the drag force of a 600 BHP Le. Mans car, travelling at a top speed of 330 km/h (91. 6 m/s) as 8. 8 k. N – does this seem about right? YES NO Try Again Correct. Use power (k. W) = force (N) x velocity (m/s) to determine drag force. NEXT >> CONFIDENTIAL COPYRIGHT © 2018

fp dra 0 000 150 70, g= 000 450 =1 00 olt =3 n= isto car h ngt ger o op n sse tre 4 b it M lim ps sile Pa Ten Gri t on ce For Estimation – Force (N) Q. You calculate the tensile strength of an M 8 bolt, using 1300 MPa UTS material as 45 k. N is this reasonable? YES NO Try Again Unbrako list their M 8 Cap screws as 47. 6 k. N NEXT >> CONFIDENTIAL COPYRIGHT © 2018

fp dra 0 000 150 70, g= 000 450 =1 00 olt =3 n= isto car h ngt ger o op n sse tre 4 b it M lim ps sile Pa Ten Gri t on ce For Estimation – Force (N) Q. You design a motor-cycle foot-rest – using a single bar for both feet – to be attached to the frame using two M 4 bolts, the person standing on the foot rest weighs 76. 5 kg, is this a reasonable design? YES NO 76. 5 kg = 750 N, but the foot rest will have to cope with shock loads, perhaps up to 3’g’ = 2250 N, overwhelming the two M 4 bolts. CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

dra 0 000 150 70, g= 000 450 =1 00 olt =3 n= isto car fp ger o op n sse h ngt 4 b it M lim tre ps sile Pa Ten Gri t on ce For Estimation – Force (N) 750 N Weight of a 76. 5 kg person 8, 888 N Le. Mans car drag at 330 km/h CONFIDENTIAL 47, 600 N Unbrako M 8 tensile strength COPYRIGHT © 2018

Estimation – Rotating Inertia (kg. m 2) Crankshaft = 0. 045 kg. m 2 Car wheel = 0. 35 kg. m 2 Ice-skater (arms out) = 100 kg. m 2 Ice skater (arms in) = 75 kg. m 2 Passenger car yaw moment = 2000 – 5000 kg. m 2 CONFIDENTIAL COPYRIGHT © 2018

Estimation – Rotating Inertia (kg. m 2) r r ca 0 nge 00 sse t = 2 pa n all me Sm mo yaw ska 100 t= ou 75 ms in = , ar ms ter , ar ter ska 5 0. 3 el = he 45 0. 0 ft = V, SU can a in eri erti 0 Am in = 500 ge t of Lar men yaw mo Ice rw Ca sha nk Cra Q. Your test department have measured the rotational inertia of your single seater racing car on its three principal axes. They have specified the answers in the test sheet as follows; Pitch = 1, 000 kg. m 2, Yaw = 225 kg. m 2, Roll = 1, 000 kg. m 2, does this seem right? YES NO The numbers are entered into the wrong boxes, 1000 kg. m 2 is about right for the yaw inertia, and 225 kg. m 2 for roll. (Also, pitch & yaw values should be similar, whilst roll should be smaller) CONFIDENTIAL Try Again NEXT >> COPYRIGHT © 2018

Estimation – Rotating Inertia (kg. m 2) r r ca 0 nge 00 sse t = 2 pa n all me Sm mo yaw ska 100 t= ou 75 ms in = , ar ms ter , ar ter ska 5 0. 3 el = he 45 0. 0 ft = V, SU can a in eri erti 0 Am in = 500 ge t of Lar men yaw mo Ice rw Ca sha nk Cra Q. You use the tri-filar (three wires) pendulum method to measure the inertia of a childrens merry-go-round, with radius 2 m and mass 100 kg, your calculations estimate that its rotational inertia is 800 kg. m 2. Is this plausible? YES NO Try Again Rotational inertia of a cylinder = 0. 5 x m x r 2 = 0. 5 x 100 x 42 = 800 kg. m 2 CONFIDENTIAL NEXT >> COPYRIGHT © 2018

Estimation – Rotating Inertia (kg. m 2) r r ca 0 nge 00 sse t = 2 pa n all me Sm mo yaw ska 100 t= ou 75 ms in = , ar ms ter , ar ter ska 5 0. 3 el = he 45 0. 0 ft = V, SU can a in eri erti 0 Am in = 500 ge t of Lar men yaw mo Ice rw Ca sha nk Cra Q. You are sizing an electric motor to accelerate a printing press roller. The roller has diameter 0. 5 m and weighs 250 kg. You calculate the inertia to be ~8 kg. m 2. Does this seem about right? YES NO Try Again Rotating inertia of a cylinder = 0. 5 x mass x radius 2 = 0. 5 x 250 x 0. 252 = 7. 8 kg. m 2 CONFIDENTIAL NEXT >> COPYRIGHT © 2018

Estimation – Rotating Inertia (kg. m 2) r r ca 0 nge 00 sse t = 2 pa n all me Sm mo yaw ska 100 t= ou 75 ms in = , ar ms ter , ar ter ska 5 0. 3 el = he 45 0. 0 ft = 800 kg. m 2 4 m dia, 100 kg childrens merry -go-round CONFIDENTIAL V, SU can a in eri erti 0 Am in = 500 ge t of Lar men yaw mo Ice rw Ca sha nk Cra 8 kg. m 2 0. 5 m dia, 250 kg printing press roller 1000 kg. m 2 Race car polar moment COPYRIGHT © 2018

Final Quiz Speed of sound in dry air (m/s) 3 34 3434 Min working temp, transmission oil (deg C) -4 - 4000 Max Combustion pressure Petrol ICE (Bar) 1. 2 12 1200 Current draw of a 120 k. W B. E. V. (A) 0. 15 1. 5 15 150 Tensile strength of an M 8 bolt (N) 47. 6 476 4, 760 47, 600 0. 045 0. 45 4. 5 45 Inertia of a Crankshaft (kg. m 2) CONFIDENTIAL COPYRIGHT © 2018

Estimation What have we learned? - You now have a reference framework for various units - You can readily sanity check calculation outputs against your reference framework CONFIDENTIAL COPYRIGHT © 2018

THANK YOU Doug Cross, Founder Tel. +44 (0) 7825240709 E: doug. cross@leadfoot. ltd CONFIDENTIAL COPYRIGHT © 2018

Accelerator programme – short courses Doug Cross, Founder Tel. +44 (0) 7825240709 E: doug. cross@leadfoot. ltd CONFIDENTIAL COPYRIGHT © 2018

ACCELERATE YOUR CAREER WITH TRAINING FOR YOUR NEXT POSITION Leadership Position Senior Manager e. g. Dept head, Programmemanager, etc Senior Engineer Team Leader - Engineering application - Estimation - Innovation - Confidentiality - Technical Risk Management - Managing teams - Systems Eng. - Budgets - Project planning - Forecasting - IP - Technical Risk Management Managing Director / Owner - Workforce drive - Direction setting - Finance - Strategy - Planning - Legal (NDA’s, employment contracts) - IP Creation - Tech / Org Risk Management CONFIDENTIAL - - - Vision setting - Dealing with Workforce drive corporate finance Direction setting team Finance - Strategy - Planning Competitor - KPI’s benchmarking - How to deal with Planning legal team (eg. Deal making Mergers & Legal (Competition acquisitions) law, Employment - Commercialising law, H&S, Contracts, IP etc) - Healthy risks IP Strategy Organisational Risk mitigation COPYRIGHT © 2018