Since the correlation given in the textbook is so complicated, for convection over a sphere. proposes the correlation to be NUD = 2+ C Re Pr¹/3 used a steel sphere (conductivity of 42 W/m-K) of 20 cm diameter that generates steady 40 W heat. placed it in air flow with 1 m/s where air temperature is 20°C. then measured the steady state tempera- ture of the sphere surface to be 30°C. Based on come up with a new correlation 2 measurements, what is the convection coefficient? 318 W/m²K Using properties at film temperature, what should the value of C be as per assumes m = 0.8? 0.142 What is the temperature at the center of the sphere? 30'38 ℃ calculations if

Since the correlation given in the textbook is so complicated, for convection over a sphere. proposes the correlation to be NUD = 2+ C Re Pr¹/3 used a steel sphere (conductivity of 42 W/m-K) of 20 cm diameter that generates steady 40 W heat. placed it in air flow with 1 m/s where air temperature is 20°C. then measured the steady state tempera- ture of the sphere surface to be 30°C. Based on come up with a new correlation 2 measurements, what is the convection coefficient? 318 W/m²K Using properties at film temperature, what should the value of C be as per assumes m = 0.8? 0.142 What is the temperature at the center of the sphere? 30'38 ℃ calculations if

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter2: Steady Heat Conduction

Section: Chapter Questions

Problem 2.25P: Show that the rate of heat conduction per unit length through a long, hollow cylinder of inner...

See similar textbooks

Similar questions

Show that the rate of heat conduction per unit length through a long, hollow cylinder of inner radius ri and outer radius ro, made of a material whose thermal conductivity varies linearly with temperature, is given by qkL=TiTo(rori)/kmA where Ti = temperature at the inner surface To = temperature at the outer surface A=2(rori)/ln(ro/ri)km=ko[1+k(Ti+To)/2]L=lenthofcyclinder
Since the correlation given in the textbook is so complicated, Dr. Roy wants to come up with a new correlation for convection over a sphere. He proposes the correlation to be NUD D=2+C Re" Pr3 He used a steel sphere (conductivity of 42 W/m-K) of 20 cm diameter that generates steady 40 W heat. He placed it in air flow with 1 m/s where air temperature is 20°C. He then measured the steady state tempera- ture of the sphere surface to be 30°C. 31'8 w/m² K Based on his measurements, what is the convection coefficient? Using properties at film temperature, what should the value of C be as per Dr. Roy's calculations if he assumes m = 0.8? O'142 What is the temperature at the center of the sphere? 30 38 C
Q4/The outside wall of a building 6 m high receives an average radiant heat flux from the sun of 1100 W/m². Assuming that 95 W/m² is conducted through the wall, estimate the outside wall temperature. Assume the atmospheric air on the outside of the building is at 20°C. Ans. 170°C
Q6 a) A 10-cm dia. copper ball is to be heated from 100 °C to till average temperature of 150 °C in 30 min time. The average density is 8950 kg/ m and the specific heat is 0.395 kJ/kg°C. Find (i) Total amount of heat transfer, (ii) Average rate of Heat Transfer, (ii) Average Heat Flux b) A plane wall constructed of solid iron with thermal conductivity 70 W/m C, thickness 50 mm and with surface area 1 m by 1 m, temperature 150 °C on one side and 80°C on the other. Calculate the conductive heat transfer.
Q2/ An aluminum sphere weighting 7kg and initially at a temperature of 533K is suddenly immersed in a fluid at 283K. if heat transfer coefficient between the sphere and fluid is 50W/m?.°C. Take density=2707kg/m3, specific heat=0.9KJ/kg.°C and thermal conductivity= 204W/m °C. إجابت * Determine the Bi number 0.00696 0.000696 0.0052 0.00052 0 أخری *.Determine the time required to cool sphere to 263K 26.28min 262.8min 52.56 min 525.6 min O أخری
Q2/ A (2 cm) thick steel plate of thermal conductivity (50 W/m.°C) has a uniform heat generation of (40 x 106 W/m³). The temperature at the left surface of the plate is (160 °C) and at the right surface is (100 °C) start from principle to find the place and the value of the maximum temperature. (25 marks)
A 2m^2 wall of 1010steel is 8 mm thick. If the outside of the wall is100 °C, andyou measure aheat flux of 80 kW/m2coming off the wall, what is the temperature of the insideof thewall?
A large 100-mm thick steel plate is initially at uniform temperature T = 180°C at time t = 0. Both sides of the plate are exposed to 30°C oil with convection coefficient h = 1500 W/m².K. The thermal conductivity, heat capacity, and density of the steel are k = 38 W/m-K, cp = 485 J/kg-K, and p = 7800 kg/m³. a) Find the temperature at the center of the slab when t = 125 s. b) Find the temperature at the surface of the slab when t=125 s.
Convection heat transfer from a plate (2 m x 2 m) is 450 W. If surface temperature of plate is 450 K and surrounding temperature is 300 K, what will be value of heat transfer coefficient?
The wall of a furnace comprises three layers as shown in the figuie. The first layer is tery (whose maximum allowable temperature is 1400°C) while the second laver is Tracto:y Chose maximum allowable temperature is 1093°C). The third layer is a plate of 6 35 od thermal contact. Steet plare To 6.35x3 45A 1370 C Concerntiation veluciy 37.8 C mass Siynes Figure. Layers in a composite furnace wall. e temperature To on the inside of the refractory is 1370°C, while the temperature T; on the side of the steel plate is 37.8° The heat loss through the furnace HnIlisexpectet tobe
Please solve only part 3. This is a 3-part question involving heat transfer. Part 1 and 2 are correct, but I need help how to find part 3. Thank you.
Q.32 Computer memory chips are mounted on a finned metallic mount to protect them from overheating. A 152 MB memory chip dissipates 5 W of heat to air at 25°C. If the temperature of this chip is to not exceed 60°C. The overall heat transfer coefficient-area product of the finned metal mount must be atleast W/°C.