Question

(1 point) A large cylinder with diameter D = 55 cm is at uniform temperature of T, = 450° C. A fan that blows air at temperature T㎡ = 25°C to cool the cylinder down. The convection coefficient is estimated to be h 110W/m2. K. The safe temperature for handling is Tsafe 55C. The properties of the cylinder are p 2700 kg/m3,c975 J/kg.K and k 20 W/m.K. A conservative measure imposes that the entire object has to reach to the safe temperature. a) Compute the Biot number to check if LPA is valid. Bi- b) Is LPA valid? no ф c) How long should the plate be left exposed to air? 0.7563 d) is using 1-term approximation valid? yes φ

0 0
Add a comment Improve this question Transcribed image text
Know the answer?
Add Answer to:
(1 point) A large cylinder with diameter D = 55 cm is at uniform temperature of...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • an aluminum sphere with an 8 cm diameter is exposed to 60C air with convection heat...

    an aluminum sphere with an 8 cm diameter is exposed to 60C air with convection heat transfer coefficient of 35 W/m^2 K. the initial temperature of the phsere is 5 C. a. computer the biot number. b. computer the temperature at the center of the sphere after 5.5 min exposure to the hot air. c. confirm that the lump application is valid.

  • Problem 2. A long 6.5 cm diameter solid cylinder steel (K 16.3 W/m. K,p 7817 kg/m3,...

    Problem 2. A long 6.5 cm diameter solid cylinder steel (K 16.3 W/m. K,p 7817 kg/m3, Cp 460 J/kg.k). It's initially at a uniform temperature of T 150°C. It is suddenly exposed to a convection environment with h-285 W/m2 K and Too 50°C. Calculate the temperature at 1.) the axis of the cylinder, and 2.) a 2.5 cm radial distance after 5 min of exposure to the cooling flow. (20%)

  • A large wall made of 10-cm-thick solid brick (k = 0.8 W/m.K, p 2000 kg/m3, and p 800 J/kg.K) is o...

    Heat transfer question. A large wall made of 10-cm-thick solid brick (k = 0.8 W/m.K, p 2000 kg/m3, and p 800 J/kg.K) is originally at a uniform temperature of 30°C. The wall is adiabatic (well insulated) on one side as shown in the figure. The other surface is suddenly exposed to convection air flow at 10°C, resulting in a heat transfer coefficient h=40W/m2.K. Fluid (4.1) Determine the temperature of both surfaces Gr 0 and x 10 cm) after 5 hr...

  • A cylinder with diameter D=6mm has a volumetric heat generation of 176.8×105 W/m3. The surface is...

    A cylinder with diameter D=6mm has a volumetric heat generation of 176.8×105 W/m3. The surface is exposed to air convection with a velocity of V∞ =11.11m/s and temperature at T∞=10 °C. You can initially evaluate air thermal properties at T∞ using Table A.4 or any other available data. (a)Determine the surface temperature Ts of the cylinder (12 points). (b)Is it reasonable to use T∞ rather than the film temperature to evaluate the air properties in this case (3 points)?

  • Problem 5.049 A long cylinder of 30-mm diameter, initially at a uniform temperature of 1000 K,...

    Problem 5.049 A long cylinder of 30-mm diameter, initially at a uniform temperature of 1000 K, is suddenly quenched in a large, constant-temperature oil bath at 350 K. The cylinder properties are -1.7 W/m-K, 1600 J/kg-K, and 400 kg/m2, while the convection coefficient is 53 W/m2-K. Step 1 When deciding if the lumped capacitance method can be used, what is the value of the Biot number? the tolerance is +/-296 By accessing this Question Assistance, you will learn whille you...

  • , A tite ditèrence analysis vestir coeficient is h. sis has been performed on the fin of diameter D using a uniform spacing o perfi at each node has been obtained. The thermal conducti has been obtai...

    , A tite ditèrence analysis vestir coeficient is h. sis has been performed on the fin of diameter D using a uniform spacing o perfi at each node has been obtained. The thermal conducti has been obtained. The thermal conductivity of the fin is & and the ambient flow hich discretized equation for node T, is correct? f Ax and the equatio s A hole is drilled through the center of a solid block of square cross section. The hole...

  • A long cylinder of diameter D 0.012 m, thermal conductivity k 358 W/(mK), density p -...

    A long cylinder of diameter D 0.012 m, thermal conductivity k 358 W/(mK), density p - 7614 kg/m3, specific heat c 418 J/(kgK) is initially at a uniform temperature of Ti-74°C. The cylinder is suddenly exposed to a gas at T,-18 ℃ The convection coefficient is h -17 W/(m2K). Verify that a lumped capacitance analysis can be used for the transient response of the cylinder temperature. What is the time t in seconds for the cylinder temperature to become Tf-32...

  • 1. Heat is generated at a uniform steady rate in a long solid cylinder. The cylinder...

    1. Heat is generated at a uniform steady rate in a long solid cylinder. The cylinder loses heat from its exposed surface to surroundings at constant temperature. Show that the radial temperature profile in the cylinder can be represented by the equation: T, = Twer - 9 4k where qy is the rate of heat generation per unit volume and Tur is the maximum temperature in the profile. [30%] In a long solid cylinder of 40mm diameter heat is generated...

  • This is for static air don't just copy from others', this is a different problem. 1. A very long horizontal cylinder of Unobtainium, of diameter 100 mm, is initially at a uniform temperature...

    This is for static air don't just copy from others', this is a different problem. 1. A very long horizontal cylinder of Unobtainium, of diameter 100 mm, is initially at a uniform temperature of 500 K. The cylinder is left to cool in a large room of static air at 300 K. Calculate a) the average convective heat transfer coefficient at the beginning of the cooling process when the initial temperature of the cylinder is 500 K, and 10] 15]...

  • A long horizontal cylinder with diameter of d-60 mm and length of L-1 m is at 27°C and is placed ...

    A long horizontal cylinder with diameter of d-60 mm and length of L-1 m is at 27°C and is placed in a quiescent environment at 4°C. Find the cooling rate (q). End effects (heat transfer from the two ends of the cylinder) are negligible. The following relation (Churchill and Chu) for Nusselt number can be used. Air (T-288.5K): v=14.87x10° m2/s, k=0.0254 w/m-K, α=21.0x10-6 m2/s, Pr-0.71, B-3.47x1031/K. 1. Quiescent air 7,-4°C 0.06 m diameter T 27 C L=1m MUD 10.60 +...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT