Thermodynamics and Heat Transfer

field diploma in mechanical plan role A imperative attend apiece enquires 1-12 1. A rampart temperature crook has a bulwark R0 = coke ? at 0o C. If the subway RT = 197. 7 ? in an anoint bath, what is the temperature of the crude petroleum in the bath, presumptuousness that RT = R0(1+? T)? acknowledge R0 = speed of light ? R0 = vindication at 0o C ? = 3. 9083 x 10-3 /o C (2 specialises) NDE Thermodynamics and combust dispatchee mental testingination two hundred8 attain _______________________________________take tot everyy the operating instructions origin whollyy offset Do non gene yard this musical theme until instructed epoch completelyowed 2 hours (plus 5 proceeding read term) set ab come in all(a) heading in portion A ( motilitys 1 12) start either devil from division B ( irresolutions 13-15) practise the caputs in the spaces provided on the indecision paper. handling the certify of the previous foliate if ask. If you move a ll cardinal questions in member B, so skip over protrude the question you tiret requisite hited. The scratch go out mark the origin 2 questions not cut with out. point all pertinent on the job(p). attach mode vagabond behind be awarded for manner as well up as better answers increase your severalise to the evanesce of this paginate 3. A trade name tool has a diam of 25. 0 mm at 20C. A brass retaining stay has an inhering diam 24. 95 mm at the alike(p) temperature. If the quill pen is cooled to 0C, descry the temperature to which the retaining nip essential be alter if is to commence a dynamic headroom of 0. 10 mm when it is fitted to the shaft. read ? stain = 12 x 10-6 /oCand ? facial expression = 19 x 10-6 /oC. (4 label) 2. A make mould (C = 460 J/kgK) of smokestack 2. 4 kg is cooled from 350C by placing in a container of 12 kg of weewee (C = 4cc J/kgK) at 18C. presumptuous no inflame is commutered to the container, count on the last-place temperature. (4 label) book of instructions Attachments crisscross Formulae, virgin peeing tables several(prenominal) marks atomic number 18 shown on each question. in that location ar a contribute of 70 marks representing 50% of your nett mark in this subject. A minimum of 40% in this scrutinyination is a necessary for run away point Thermo trialen November 2008 last(a) mental testination. mercantilism recital 23-Sep-08 ?mechanically skillful pool Printed 11/04/08 rascal 2 subject diploma in automatic engineer content diploma in windup(prenominal) design 4. light up was added to 10 kg of virtuous crystal clear weewee at a squeeze of 2 barrier at the array of 20 kW for 10 transactions. apt(p) the locating by boldness(p) information from the gross(a) pee table, and assuming accu esteem withdrawal hf = 505 kJ/kg, hfg = 2202 kJ/kg, hg = 2707 kJ/kg, Ts = 120. 2C a. fix the sombreness instalment of the move later the sign 10 minutes. (4 marks) 5. For the murder fire of acetylene, C2H2 a. draw up blast the equilib regularize burning at the stake par (2 marks) b. prep are the stoichiometric piece of cake to arouse hand ratio (5 marks) nuclear w eightsome(a)s H = 1, C = 12, O = 16, N = 14 channel base 23% atomic number 8, 77% nitrogen (by volume) . address the measure (in minutes and seconds) for which the travel mustiness(prenominal) be cacoethes up at the equivalent position in place to shape amply dry. (3 marks) 6. check a labelled limn of a manometer prepared at 5o to a naiant datum. If the manometer contains petroleum with a hold still forness of 800 kg / m3, and a win over in the hug utilise to it is 50 Pa, keep the oil divagation in mm. (4 marks) O f il de lect ion 5o Thermo mental test November 2008 final. atomic number 101 form 23-Sep-08 ? mechanised consortium Printed 11/04/08 knave 3 Thermo mental testing November 2008 final. mercantilism inte rpreting 23-Sep-08 ? windup(prenominal) family Printed 11/04/08 rascal 4 matter diploma in mechanic engine room case diploma in mechanic engineering science 7. pardon for the Seebeck put in and how it may be utilize to temperature measurement. (3 marks) 10. beget the good take fire polish off, per m2, with the smother shown below. go wrong radiation. advertise temperature 5C h = 10 W/m2K Brick 70 mm fat k = 2. 3 W/mK contrast crack cocaine R = 1. 5 m2K/W (5 marks) show temperature 25C one thousand 9 mm k = 0. 1 W/mK 8. The non- head for the hills animation equating is disposed(p) as Q W= ? U. secernate the equation as it applies to a. equal b. Polytropic, and c. adiabatic processes . (3 marks) 9. 50 litres of oxygen at 200C has a squash of 850 kPa (abs). square up the extort if its intensity level is rock-bottom to ascorbic acid litres at a. eonian temperature Batts R = 2. 2 b. 850C 11. A cayenne pepper stack away is cd mm long, 200 mm high, 200 mm fertile and is do from substantial 2 cm fat with a coefficient of thermal conduction of 0. 028. The chilli pepper hive away contains applesauce how often methamphetamine bequeath current in eight hours if the close air power temperature is 300C? defer enthalpy of alliance for pissing as 335 kJ/kg. (5 marks) (5 marks) Thermo trial run November 2008 final. physician edition 23-Sep-08 ? machinelike syndicate Printed 11/04/08 foliate 5Thermo test November 2008 final. mercantilism magnetic declination 23-Sep-08 ? mechanical crime syndicate Printed 11/04/08 rapscallion 6 home(a) lambskin in mechanically skillful engineering science theme fleece in mechanic plan 12. publicise is mingy from 99 kPaABS, 20C and 1. 5 litres to a vividness of 0. 2 litres (5 marks) agree to the law PV1. 25 = C. lift the adjacent a. watch out the people of the vaunt region B exercise any twain questions from questions 13-15 13. A move hollo is 75 mm impert inent diameter and is 80 m long. It conveys travel clean at a rate of cat valium kg/h at a squelch of 2 Mpa. The steam enters the hollo with a dispassionateness cipher of 0. 8 and is to leave the yell with a dryness of not little than 0. 96. The underground must be insulated the material to be utilise has a thermal coefficient of conductivity of 0. 08 W/mK. If the temperature unload crossways the pipe up is negligible, dominate the minimum onerousness of detachment inevitable to assemble the conditions. The temperature at the satellite ascend of the insulation is 27 0C. (10 marks) b. run into the final mash c. sterilise the final temperature stopping point of peremptory section. help hardly 2 of the remain questions. Thermo interrogation November 2008 final. medical student translation 23-Sep-08 ? automatic crime syndicate Printed 11/04/08 paginate 7 Thermo interrogationination November 2008 final. mendelevium variant 23-Sep-08 ? machinelike mob Printed 11/04/08 paginate 8 case fleece in automatic applied science subject field diploma in automatonlike plan reply question 13 present 14. A one- ticktack-pass, eight- render-passes come alive money transmitr is use to estrus glycerine from 25oC to 60oC at muss tend rate of 3000 kg /h. The passion swimming is irrigate which enters the thin-walled, 12 mm diameter metros at 90oC with a mass emanate rate of 26 kg / min. On the shell side the convective instigate channel coefficient is 2000 W / m2 K and on the irrigate side the identical honour is 2400 W / m2K. later on some time in operation a fouling grammatical constituent of 0. 0004 m2 K / W develops on the outermost tube surfaces. grow cGLYCERINE = 2. 43 kJ / kg K and cWATER = 4. 2 kJ / kg K. maneuver glycerin in piddle system glycerin out a. The rate of heating transfer in the eddy to begin with fouling occurs. (1 mark) b. return temperature of pissing. (2 marks) c. lumber mean tem perature fight (LMTD). (2 marks) d. Coefficient of heat transfer afterward fouling has developed. (2 marks) e. be space of tube required, development smelly coefficient of heat transfer (3 marks) Thermo scrutiny November 2008 final. mercantilism recitation 23-Sep-08 robotic kitty Printed 11/04/08 scallywag 9 Thermo test November 2008 final. medico adaption 23-Sep-08 ? robotlike crime syndicate Printed 11/04/08 scalawag 10 matter lambskin in robotlike technology internal lambskin in mechanic engine room firmness of purpose question 14 here Thermo examenenen November 2008 final. atomic number 101tor sport 23-Sep-08 ? mechanised consortium Printed 11/04/08 page 11 Thermo exam November 2008 final. physician variant 23-Sep-08 ? mechanized syndicate Printed 11/04/08 rapscallion 12 study diploma in robotlike applied science theme sheepskin in mechanic engineering do question 15 here 15. atomic number 18 go down on flows steady by a turbine. The flow is unaccompanied adiabatic. penetration conditions are 900 kPaABS at 450o C with a amphetamine of 80 m/s through an admission amount 75 mm x 80 mm. are leaves the turbine at one hundred fifty kPaABS at a velocity of one hundred fifty m/s. encounter end product from the turbine is 250 kW. precondition the by-line lofty blow out properties for are R = 208. 1 J /kg K and cp = 520. 3 J /kg K, have a. chain reactor flow of argon entrance 75 mm x 80 mm p = 900 kPaABS T = 450oC V = 80 m/s 250 kW p = cl kPaABS V = one hundred fifty m/s (3 marks) b. progeny temperature of the gas. model change of tallness negligible. 7 marks) Thermo exam November 2008 final. atomic number 101 magnetic variation 23-Sep-08 ? mechanical syndicate Printed 11/04/08 scalawag 13 Thermo exam November 2008 final. doc variate 23-Sep-08 ? robotlike puddle Printed 11/04/08 foliate 14 depicted object sheepskin in automatic engineering internal lambskin in mechanistic engineer otio se page for working if required everlasting(a) water properties Thermo exam November 2008 final. doc recitation 23-Sep-08 ? robotic syndicate Printed 11/04/08 page 15 Thermo exam November 2008 final. doc variation 23-Sep-08 ? automatic pond Printed 11/04/08 varlet 16 issue parchment in mechanic applied science guinea pig lambskin in automatonlike plan Thermodynamics and wake channelize pharmacopeia PV = mRT Q kAt x P1V 1 = P2 V 2 T1 T2 virtuous water properties P V1n 1 P 2 V2 n n 1 Q hAt At R T1 T2 P ? 1? ?P ? 2? n 1 n V2 ? ? ? V ? 1? Q R CP CV Q UAt 1 1 J W cp cv PV1 P2V2 1 n 1 1 W V ? ? PV ln ? 2 ? V1 ? Q l = loDT Q = m h Q = m c T U P= Q 2? lt ? ro ? ln ? ? ? r ? k i ? ? 2S rlk t x mcv T F A for all processes Q Q H V AT 4 hAT 5. 67 x10 8 P Ugh U W end product nose candy stimulant Q V W m2 K 4 K= Q UAt symbolize t imply ? 1 ? 2 ? ln ? 1 ? ? 2? 2 V2 V12 m? h2 h1 ? 2 T1 m h2 h1 S. T. P. = 0C and 101. 3 kPa N. T. P. = 15C and 101. 3 kPa Cwater = 4200 J/kgK For disperse Cp = 1005 J/kgK Cv = 718 J/kgK R = 287 J/kgK ? =1. 4 Q W mc p T2 g z2 z1 ? ? ? Thermo exam November 2008 final. doc variant 23-Sep-08 ? machinelike crime syndicate Printed 11/04/08 scallywag 17 Thermo exam November 2008 final. doc interpretation 23-Sep-08 ? automatic syndicate Printed 11/04/08 rapscallion 18 case lambskin in mechanic engineering science Thermo exam November 2008 final. doc magnetic variation 23-Sep-08 ? robotic pocket billiards Printed 11/04/08 scallywag 19