Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
8th Edition
ISBN: 9781305387102
Author: Kreith, Frank; Manglik, Raj M.
Publisher: Cengage Learning
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Chapter 2, Problem 2.16P
To determine
The increase in heat transfer.
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In boiling water at 1 atm pressure outside a stainless-steel tube with a surface temperature of 410F, the heat-transfer coefficient h in the absence of radiation is 32 Btu/h*ft^2*F. If the emissivity of the stainless steel is 0.8, will radiation significantly augment the rate of boiling (e.g., by more than 5 percent)? Assume that the vapor film is transparent to radiation and the boiling liquid is opaque.
Water at atmospheric pressure is boiled in a container using a horizontal 8 mm electric wire (ε=0.9) whose temperature is maintained by an electric current at 250oC. Estimate the boiling heat transfer coefficient between the water and the wire surface. Properties of Water, liquid: ρl = 957.9 kg/m3, hfg = 2257 kJ/kg, vapor: ρv = 4.8 kg/m3, Cp,v = 2560 J/kg.K, μv = 14.85*10-6 N.s/m2, kv=0.0331 W/mK.
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a. 247 W/m2K
b. 440 W/m2K
c. 90.7 W/m2K
d. 710 W/m2K
Water is to be boiled at atmospheric pressure in a polished copper pan by means of an electric heater. The diameter of the pan is 0.51 m and is kept at 111 deg C. What is the power required to boil the water? Tsat = 100°C; Properties of water at 100°C: Density, ρl= 961 kg/m3; Kinematic viscosity, ν = 0.293x10-6 m2/s; Prandtl Number, Pr = 1.740; Specific heat, Cpl = 4216 J/kg.K; Dynamic viscosity, μ = ρ × ν = 961 × 0.293 × 10-6 = 281.57 x10-6 Ns/m2; hfg = 2256.9 kJ/kg; ρv = 0.597 kg/m3; σ = 0.0588 N/m; Csf=0.013; n=1;
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Chapter 2 Solutions
Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
Ch. 2 - A plane wall, 7.5 cm thick, generates heat...Ch. 2 -
2.2 A small dam, which is idealized by a large...Ch. 2 - 2.3 The shield of a nuclear reactor is idealized...Ch. 2 - A plane wall 15 cm thick has a thermal...Ch. 2 - 2.5 Derive an expression for the temperature...Ch. 2 - A plane wall of thickness 2L has internal heat...Ch. 2 - 2.7 A very thin silicon chip is bonded to a 6-mm...Ch. 2 - 2.9 In a large chemical factory, hot gases at 2273...Ch. 2 - 2.14 Calculate the rate of heat loss per foot and...Ch. 2 - 2.15 Suppose that a pipe carrying a hot fluid with...
Ch. 2 - Prob. 2.16PCh. 2 - Estimate the rate of heat loss per unit length...Ch. 2 - The rate of heat flow per unit length q/L through...Ch. 2 - A 2.5-cm-OD, 2-cm-ID copper pipe carries liquid...Ch. 2 - A cylindrical liquid oxygen (LOX) tank has a...Ch. 2 - Show that the rate of heat conduction per unit...Ch. 2 - Derive an expression for the temperature...Ch. 2 - Heat is generated uniformly in the fuel rod of a...Ch. 2 - 2.29 In a cylindrical fuel rod of a nuclear...Ch. 2 - 2.30 An electrical heater capable of generating...Ch. 2 - A hollow sphere with inner and outer radii of R1...Ch. 2 - 2.34 Show that the temperature distribution in a...Ch. 2 -
2.38 The addition of aluminum fins has been...Ch. 2 - The tip of a soldering iron consists of a 0.6-cm-...Ch. 2 - One end of a 0.3-m-long steel rod is connected to...Ch. 2 - Both ends of a 0.6-cm copper U-shaped rod are...Ch. 2 - 2.42 A circumferential fin of rectangular cross...Ch. 2 - 2.43 A turbine blade 6.3 cm long, with...Ch. 2 - 2.44 To determine the thermal conductivity of a...Ch. 2 - 2.45 Heat is transferred from water to air through...Ch. 2 - 2.46 The wall of a liquid-to-gas heat exchanger...Ch. 2 - Prob. 2.47PCh. 2 - The handle of a ladle used for pouring molten lead...Ch. 2 - 2.50 Compare the rate of heat flow from the bottom...Ch. 2 - 2.51 Determine by means of a flux plot the...Ch. 2 - Prob. 2.52PCh. 2 - Determine the rate of heat transfer per meter...Ch. 2 - Prob. 2.54PCh. 2 - 2.55 A long, 1-cm-diameter electric copper cable...Ch. 2 - Prob. 2.56PCh. 2 - Prob. 2.57PCh. 2 - Prob. 2.58P
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