Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470917855
Author: Bergman, Theodore L./
Publisher: John Wiley & Sons Inc
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Chapter 7, Problem 7.109P
(a)
To determine
The mean outlet temperature of the helium leaving the bed and the amount of thermal energy generated by each pellet.
(b)
To determine
The maximum internal temperature of the hottest pellet in the packed bed.
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Chapter 7 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 7 - Consider the following fluids at a film...Ch. 7 - Engine oil at 100C and a velocity of 0.1 m/s flows...Ch. 7 - Consider steady, parallel flow of atmospheric air...Ch. 7 - Consider a liquid metal (Pr1), with free stream...Ch. 7 - Consider the velocity boundary layer profile for...Ch. 7 - Consider a steady, turbulent boundary layer on and...Ch. 7 - Consider flow over a flat plate for which it is...Ch. 7 - A flat plate of width 1 m is maintained at a...Ch. 7 - An electric air heater consists of a horizontal...Ch. 7 - Consider atmospheric air at 25C and a velocity of...
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- An ordinary egg can be approximated as a 5.5-cm-diameter sphere whose thermal conductivity of roughly k = 0.6- W mk overall density of p = 1000; and heat capacity of C₂ = 3000- kg m² The egg is initially at a uniform temperature of T₂ = 10°C and is dropped into boiling water at T.. = 90°C W - determine how long it will take for the egg to m²K Taking the convective heat transfer coefficient to be h reach T = 70°C. In solving the problem, please follow the steps below. For the Lump Model In solving this problem, please use the lump model method (ignoring the requirement of small Biot number and discuss the outcomes, 1. 2. Compute the characteristic length Lc Compute the volume and surface area of the sphere (as the egg model) Vol As 3. Compute the diffusivity α = = 10- k p Cp = J kgk Compute non-dimensional excessive temperature 0 = h Lc k 4. Compute the Biot number using the characteristic length found above Bi = T-Too 5. Ti-Too 6. Calculate the Fourier number from the equation =…arrow_forwardA 30-cm-radius metallic sphere is having thermal conductivity of k = 100. overall density of W 7 mk p = 1500- kg m² and heat capacity of C₂ = 3000 The sphere is initially at a uniform temperature of kgk CO T₁ = 20°C and is dropped into boiling water at T = 90°C. The convective heat transfer coefficient is assumed to be only h = 50; W m²K Using lump model, compute the temperature of the sphere after t = 1200 seconds. In solving this problem, please use and show the following steps (do not use EES) 1. Compute the volume and surface area 2. Compute the characteristic length Lc = k p Cp h Lc 4. Compute the Biot number Bi k 5. Calculate the Fourier number Fo= (at)/Lc² 6. Calculate the excess temperature using 0 = exp(-Bi * Fo) T-Too 7. Compute the target temperature T using 0 = Ti-Too 3. Compute the diffusivity a = = the sphere Vol Vol As == 3 r³ and А¸ = 4πr²arrow_forwarda) A turbine blade 6 cm long and having a cross sectional area 4.65 cm and perimeter 12 cm is made of stainless steel (k=23.3 Wim K). The temperature at the root is 500 C. The blade is exposed to a hot gas at 870 °C. The heat transfer coefficient between the blade surface and gas is 442 W/im K. Determine the temperature distribution and rate of beat flow at the root of the blade, Assume the tip of the blade to be insulated. b) The hot combustion gases of a fumace are separated from the ambient air and its surounding, which are at 20°C, by a brick wall 0.5 m thick. The brick has a themal conductivity of 5 W/mk and a surface emissivity of 0.6. Under steady-state conditions an Page no.1 of 1 outer surface temperature of 120°C is measured Free convection heat transter to the air adjoining the surface is characterized by a convection coefficient of 15 Wim K What is the brick inner surface temperaturearrow_forward
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- Need help on the Q.arrow_forwardThe 0.5 m x 1.2 m wall of an industrial furnace is constructed from L = 0.15-m-thick fireclay brick having a thermal conductivity of 1.7 W/m-K. The temperature distribution, at an instant in time, is T(x) = a + bxwhere a = 1400 K and b = -1050 K/m. Determine the heat fluxes, q, and heat rates, q,, at x = 0 and x = L, in W/m2 and W respectively. Do steady-state conditions exist? W/m2 1x=0 i W/m? i W Ix=0 = Ir=L = i W Steady-state conditions exist.arrow_forward8--The reactor from uniform carbide and graphite as a cylinder rod with diameter of 12 mm. The volumetric heat liberationis 3.88x108 W/m3 The thermal conductivity of the rod material is 85 W/mC.. Determine the heat losses from the rod and the surface temperature if the maximum temperature of the rod is 200C...Ans Tw=1940 C,,Heat losses=1.164 MW/m2.arrow_forward
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