Quiz+3+Key+2009

# Quiz+3+Key+2009 - QPIZ#3 Sprung 2009 Name Kg Problem...

This preview shows pages 1–10. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: PTFE 32 10 QPIZ #3 Sprung 2009 Name Kg \/ Problem Maximum Score Séore 1 25 2 25 3 25 4 25 Totai 106 PTFE 3210 Quiz 3 Spring 2009 Name____ 1. Three large sheets of plastic are to he glue together. All of the sheets are made from the same plastic (thermal diffusivity of 1x10"9 mzls and thermal conductivity of 0.2 W/m-K). The thickness of each of the three sheets is 0.005 m. Glue is applied to the appropriate surfaces and sheet 2 is sandwiched between sheets 1 and 3. The glue layers are extremely thin and their effect on heat transfer can be neglected. Metal platens at a constant temperature of 220°C are used to heat the plastic sheets so that the glue will set (cure). The platens are placed in direct contact on the surfaces of the outer sheets and can be assumed to instantaneously raise the temperatures of these surfaces to 220°C. The initial temperature of the plastic sheets is 20°C. A. What is the minimum time that the sheets should be heated to ensure that both glue lines reach the cure temperature of 120°C? (15 points) 5% /@z B. What is the heat ﬂux from the platens to the surfaces of the sheets when the glue lines reach the cure temperature of 120°C? (10 points) SWM/ﬂ 2. Air at a pressure of 1 atmosphere and a temperature of 300°C ﬂows with a velocity of 10 m/s over a ﬂat piate 5 m long. Calculate the cooiing rate per unit Width of the plate needed to maintain the plate at a surface temperature of 27°C. (25 points) yaw/M jéé may"? Page; If calculations are used on Question 3, please Show them if you want partial creditlt osphere has a dry bulb temperature of 85°F. 3. An air-vapor mixture at a pressure of one atm The relative humidity of the mixture is 50%. Use the attached psychrometric chart to answer the following questions: a. What is the humidity ratio (lb of water per lb of dry air) for the air—vapor mixture? (5 points) b. What is the dew point of the air—vapor mixture? (5 points) 0. What is the adiabatic saturation temperature of the air-vapor mixture? (5 points) e to a ﬁnal Ifthe air-vapor mixture was cooled under constant pressure of one atmospher temperature of 50°F: were removed in the cooling process? d. How many pounds of water per pound of dry air (5 points) air mixture in e. How much energy per pound of dry air (BTU/Pom) was removed from the (5 points) the cooling process? “93 ‘(q “’51 “*3! do” "mp °Emmmli°£9d “Ii-‘90 “10H “DESSEWR‘I 5‘1 PDIdBFV 'uuua up nwoﬁlaﬂsd 9-v Lamp 'uoymodloo mg I; ‘aJmmadLua; q|nq—Mq LU U! o amawmqaﬁsd m o " = ' .- _ Y In. ' A . - _ I :1 maximum III at». , "Ali 'DMB ML Vﬁﬁ. _ ' 3-w- :" n ') II. I. i . :" gm! 3 m mummumI umumunmm -' i D wasnmnmtwu awn-3mm; rmumrlnmnmmalnuln rams. rmhgjnm'lingnhfmm gun A I, m _. l A. ch magmmzumuawzmm 5:! L" H""“ ' "'"Q' ‘55 ‘5‘ V um'gnzqm' ‘33 I. 3~ . \gé’ mug 'gi amyé; 419/ a V - .08 B “‘ .4: A I .4 maﬁa; an m. ‘6 I G ﬁlly!Hilﬁlh‘ﬂlllﬂllﬁiidmliiYIIIIIJQ, A win Mai-Wm a —:M . . ’ ma": Alma “'9 AI - . .. ' ' . g WI! : I L I I. an...” r - 3 4‘, .3: III: .- Iu‘u a. , {ﬁn - 7 an I ‘3 am» A I/ .5 II = . an. I. I IJMI , / r 4 mm " ' II II In." ' u.th / 2 4e ' - 5 ' . : ‘ 4‘ . tannin I ‘I m I. ' I‘ xv m . - nil-gin. '19 0 nun-Imam I napalm... alum . I . I ‘ «mung-mun». If” . ' - . ~ mutual-1 ., Iliﬂllﬂllrmﬂlﬂlln, ﬁrm I . .‘r - .3 . I . I. I I IIEIIEFAIIIZIIa-Elﬂlllln... / -- mum; 11m" .' I. . L -' ' .Iﬂl .. f .. I unansgnmlmﬂgnln .. 9 . ' "warn man In. I, - - ' - ﬁlﬁlllﬂhﬂﬂlﬂllﬁﬂl’ﬂ lulu-w . uln- F uneasily _ annually-raglan»: _ man-mmmlnm ' I mammal ml .Ea-SﬁllllllhEIﬁlllﬂllb' unly‘rmvmuun Ill _-I.mmnmam Imgmnwnsaumnuunmnu w Jun-mum“ z=ulunzuamnumu I .nmqnmlnnunnnnpmm I ma ll' umuumnmaullnnasu All! 8 “IIIIIII‘lﬂﬂ'ﬂﬁiﬂﬂ!!ﬂlmllMIEIDIIHHM' I "II ‘H I I ‘ warm ' l-ﬁ‘iﬁﬂVMHFMEMEFA‘QHMﬂIIHEImHIll“58"]!lﬂnﬂlllllﬂlllﬂlhﬂil!ﬂlﬁllt IIIlIHBalmEl‘!;'ill’ﬂlllﬁ5‘lllﬂl’llﬁlwiﬁ£!ﬁllﬂ§ - ‘5 ‘ ﬂluﬂnﬁﬁllﬂﬂlﬂlﬁﬂﬂlllll Ilﬁlwxl‘ﬁﬂll’ll’ﬂ‘lllk‘ﬁlIHY . EIIYAIIIMSIIIIIHIIIIISIIIIEIIIHIHKES‘Z m iﬂlnhﬂllﬂﬂfﬂﬂmllﬂlp‘ﬂmllmﬂ “full-II J I , . I "llIﬂllilllliilﬁlllﬂllﬂﬁlilﬂl ”' Kilﬂlﬂﬂlﬂlt'llll’lulﬁllllhﬂﬂiﬁﬂﬂlﬁ' ' Illlllllli 4 n ._ - EIIIIIIIIIIFSSEZiIIhIIIﬂlﬁ "' IIIIYJIWMI", way I _I . ‘ isnlllllllﬁllIlEIEHIIlﬂlll IIIIRIWJIII’; Fﬂﬂﬂl’l ‘4 IA _ 'uEHﬂlﬂliIZIIIIIIpSIIIIIIﬁ Il'llllﬂllﬂlﬂl J I‘lllllﬂI!L!"I'JIMIIEIIHIIHIIHIIHIIHIIPASIIIIIﬂlllli‘iﬁillﬁﬂlllllllﬂliﬂlll I’JI'II'IIHIHIIIIEMWJEIIHIIllhllillﬂlllllﬁllh‘lﬁllllIﬁllllli!Ilnllilllﬁlllusil'ﬂll! Illﬂlii'll g ﬂﬂfxll‘ I ' I ‘- III! I IIJV ."II 315‘ --_ s Bl’llﬂllﬂlllll’ll’ﬂlf ‘ II II . Vlllllliri‘ .ﬂ’lll'llﬂt‘lﬂlllllﬂllﬂllliﬁ llllnlliﬂi I Iﬁlﬂlﬁﬂﬂﬂﬂlﬁﬂﬂﬂl’ I . ‘ _ lllllll" ﬂ IIIII‘IIYAIIIIHII‘IIIIMIIHIIWII HIIIIIIIMIIIYJIIEEIIIEIIEL‘ IIHIIIHIVAIIIIHIﬂl'glﬂllllmiﬁlﬂllﬂllﬂll’ . unrulmlllﬁ:i=§£:’§: ___ w umImayalasnaamInna-lunI-rﬁaaagm ,...u|‘iimunuu ligasaﬂllnggyllngu .Ilﬂllilulﬂ’lllﬂi‘.Illllﬁilllly mun-ziaulnlnw - - Hui-uln-ulilulimunnlnmnn ~ . . . .. SIIHIHIIIHESQIIllilllﬂlllillli :3:was!"aw'aagﬂwzﬁiaﬁswa‘"‘°“’°““"°””.:ga:: iii-agar: ea: 2:: w: A . . . ‘4 A :- - ' " .3 -. ﬁllﬁﬂl' .II! .Ilﬂﬁ‘l'igglliﬁlﬂ lik‘ MIME: Ii: All! I" J I I'ih - I“ “I _ - - a a c .c .o p s: p p c Io c Io p o b p 9 o o ,o- c p ,o o a .o .o a ' ' c c ‘o a a o. o O O a 8 8 8 § § § § § § 3 = 5 9 ° 3. a 3’ -g 3 3 g 8. § 4. An oven is used to heat up a continuous, cylindrical carbon ﬁber with a diameter of 10 microns (one micron equals 106 meters). The ﬁber enters the oven at a temperature of 20°C and leaves the oven at a temperature of 200°C. The air in the oven is at a temperature of 220°C, and the heat transfer coefﬁcient between the ﬁber and the air is 10 W/mz-K. The properties of the carbon ﬁber are: Density of 2 gin/ems, speciﬁc heat of 710 Iikgrn~K, thermal conductivity of 10 W/m—K, and thermal difﬁisivity of 7.0 x 10*5 rug/s. If the ﬁber is moving through the oven at a speed 100 meters per minute, how long is the oven? Note: First ﬁnd how long the fiber stays in the oven, and then caiculate the oven length. (“.25 points) Neglect both thermal radiation and the effect of heat conduction along the axis of the ﬁber. 1"- .. ‘ ,, FD .2 9'24 206 z ( ,5 we. :2 m .1 a . 7" 0 6‘ r r; __, ZSX/ mu ,mz Fla t L 121'? .&4 < / ‘ F 5 ;~\ \._.. {AK ﬂ (/OQMW)(/M {@9ng a Z EC/m ...
View Full Document

{[ snackBarMessage ]}

### Page1 / 10

Quiz+3+Key+2009 - QPIZ#3 Sprung 2009 Name Kg Problem...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online