Question

[18 pts] Consider you're making pasta and you leave your stainless-steel spoon partially immersed in boiling water The handle of your spoon is of rectangular shape (3 mm thick and 60 mm wide) and 0.15 m of the spoon's handle (L) is exposed to the kitchen air temperature of 22 °C. The convective heat transfer coefficient is determined to be 8.9 W/m2K. Determine: 1. 46 Heat transfer rate and the efficiency from your spoon. The temperature difference across the exposed portion of your spoon. The effectiveness of your spoon as a fin. Qualitatively, compare your results with those based on an infinite fin approximation-what does this mean for the fin's length, would increasing its length increase the heat transfer rate? a. b. c. d. qy Is is

Need help for Test corrections thanks so much.

Answer 1

1.3mm tor stairlen skeel 1o 100 Spoon can be considered as Trite leng m Tr. Assuming steady stats condihons oand riting th eneng balane euahom for the element . Heot conducid in to the element Heat conduclid orut hu elenment + Heat conv ested rom ts element to ss umina kis Constant

ri2 . Theni-tne .50lution is given b o Hris probl em ust have uo o boundary condi ton are ar alo d x Solwina above equaom, we 2-

(a) Heat transien nate and tne ethicien PKA ODD ) O ご 0,055025 x tanh (3.087528 )× 3 1.23 412 w for in efhicienu 3. 2 (6013) 015 (100 22) 8.9(60s oo-22) 13.2 45 336 ossile し1 , 2711 , 2 13. 245 336 x 100 32,268

b The tempear neacren e posed 丁-TK Cos m (LE -) g. g x 2 (3%。) x 10001 1000 x 15 60vS rm 20-3197 VKA Cosh|20.3391 (0,1515-х) 100-22 tfech wihnt in 3.3x(의3)(100-22) 드 34.205

Date: esult wihh those based on an İnfinite fin approximahm-what cLoe this mean for the in's lenghy o ecr een le utc oY minte approxi mahon 0:055025 ( 100-2 2 = 29195 evewe can compare tmas tc ri nu ru Hence with Increasづ len alhocuy be len om the in