A vertical oil-filled electric heating panel, 1.6m long by lm high, has a surface temperature of 84°C and convects freely from both sides. The 69 surrounding air is at 20°C. Using the correlation data given in the lectures, calculate the rate of heat transfer by natural convection. For air at 52°C , k =0.02816 W/mK, μ = 0.196 xl0-4kg/ms, Cp = 1006J/kgK, ρ = 1.086 kg/m3 Answer: 1126 W SHOW STEPS ON HOW TO REACH THIS

A vertical oil-filled electric heating panel, 1.6m long by lm high, has a surface temperature of 84°C and convects freely from both sides. The 69 surrounding air is at 20°C. Using the correlation data given in the lectures, calculate the rate of heat transfer by natural convection. For air at 52°C , k =0.02816 W/mK, μ = 0.196 xl0-4kg/ms, Cp = 1006J/kgK, ρ = 1.086 kg/m3 Answer: 1126 W SHOW STEPS ON HOW TO REACH THIS

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.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.10P: 3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the...

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A food product with 73% moisture content in a 10 cm diameter can wants to be frozen. The density of the product is 970 kg / m³, the thermal conductivity is 1.2 W / (m K), and the initial freezing temperature is -2.25 ° C. After 15 hours in the freezing medium -35 ° C, the product temperature becomes -10 ° C. Estimate the convection heat transfer coefficient of the freezing medium. Assume the can as an infinite cylinder. h = .... W / (m² K).
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A 200mm diameter spherical steel ball initially at 500°C is rapidly immersed in an oil bath that is at 20°C. The convection coefficient is h = 600W/m²-K, and the steel ball has the following properties: c= 500J/kg-K, p= 7000kg/m³, k=30W/m-K. Determine the time taken (min) for temperature at the surface of the ball to drop to 100°C.
A vertical plate is held at a constant temperature of 10oC. The surrounding air is at Tinf=100oC. For the natural convection process that is induced, where do you expect the highest heat transfer to occur? Explain.
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A food product with 80% water content in a 10 cm diameter can be frozen. Mass of the product type is 1000 kg / m³, thermal conductivity is 1.0 w / (m k), and the frozen early temperature is -1.75 ° C.After 15 hours in the freezing medium -25 ° C, the temperature of the product becomes -10 ° C. Estimating the coefficient of moving the heat of the medium freezing convection. Assume cans as an unlimited cylinder. H = Answerw / (m² k).
You are cooling the door to a large heat-treating oven, which is 3.50 m tall by 1.30 m wide, with a large fan blowing air at 25.0°C over the outside of the door. The convection coefficient associated with this cooling process is h = 57.0 W/(m2-K). The outside surface temperature of the door is 58.0°C. Find the heat transfer rate q, in units of Watts, associated with this cooling process.
Thermal jackets are typically put on cryogenicstorage tanks to minimize the heat transfer gainsfrom the surroundings. Consider a cylindercontainer that is 1.5 m long made from steel (k = 750W/m.K) with an inner diameter of 0.5 m and outerdiameter of 0.7 m. If the liquefied natural gas (LNG)inside the cylinder is maintained at 90 K, ambientconditions are Tamb = 20 °C, h = 7 W/m2.K. What is the required insulationmaterial to maintain the outer temperature of that jacket of 15 °C? Usethe end of the book and write your assumption with the right value.(Take a maximum allowed jacket thickness of Lins = 7 cm)
Thermal jackets are typically put on cryogenicstorage tanks to minimize the heat transfer gainsfrom the surroundings. Consider a cylindercontainer that is 1.5 m long made from steel (k = 750W/m.K) with an inner diameter of 0.5 m and outerdiameter of 0.7 m. If the liquefied natural gas (LNG)inside the cylinder is maintained at 90 K, ambientconditions are Tamb = 20 °C, h = 7 W/m2.K. What isthe required thermal jacket thickness to maintainthe outer temperature of that jacket of 15 °C? (Takea thermal conductivity of the insulation to be kins =0.015 W/m.K). Image credit: Okorder. Image forillustrative purposes only.